United
n g neer ng
Field Notes
States
Department
of
i
Agriculture
Forest
Service
Engineering Staff
Washington
uTSs
Volume 17
October
1985
September
D.C.
Engineering Technical
Information System
The Software Spot
Artificial
Intelligence
Slave Your Old
Demand Terminal
Serial Printer to a
Aerial
Photography
Determination
DG
or
Dasher D41 0
VDT
Flight Altitude
W Study
Metal Open-Top Drainage Structure
Flying
H P- 41 Road Data
Design System
Temporal Variations
in
Evaluation of
Structural
CADD
Traffic
Volumes
for Architectural
Engineering
Computer-Aided Design
Final Evaluation
Application
Report-Internal
Evaluation
Data Corporations
of
Control
CD2000 CADD
System
A Review
of Micro-
Mini-CADD Systems
Engineering Field Notes
Administrative
Professional
Management
Distribution
Development
Ser-vice-U.S.
This
publication
developed for the
is
an
administrative
document
of
was
that
employees
guidance
Department of Agriculture its contractors
Federal and State Government Agencies.
cooperating
of
the
Forest
and its
The text
the personal
of the
publication represents
opinions
authors. This information has not been approved for
distribution
to the public and must not be construed
as
in
the
recom-mended
instruc-tions
respective
Data
Retrieval
or
approved policy
except
procedures or mandatory
Manual references.
by Forest Service
in-formation
con-venience
The Forest Service-U.S. Department
no responsibility for the interpretation
by other than
names and
identification
of the
endorsement
any product
its
of
or
Agriculture
assumes
application of this
own employees. The
of firms or corporations
use
is
of
trade
for the
reader such use does not constitute an official
by the United States Government of
or approval
service to the exclusion
or
of
others
that
may
be
suitable.
This
information
unlimited rights
by private
Please
the sole property of the Government with
the usage thereof and cannot be copyrighted
is
in
parties.
direct
any comments or recommendations
address
publication to the following
FOREST SERVICE-USDA
Engineering
Attn
D.J.
Staff-Washington
M.J. Baggett
P.O.
Office
Carroll Editor
Editorial
Box 2417-Washington
Assistant
D.C.
20013
Telephone Area Code 703-235-8198
about
this
o
o
o
0
Q
0
The
and
CONCLUSION
rest
2
are
self-explanatory.
Figures 1
examples of the output documents.
is
Forests interested in these programs
should contact Dick Wisehart Stanislaus
National
Forest 19777 Greenley Road
Sonora California 95370 or call
209 532-3671.
--John E. Best
Supervisory Civil Engineer
Forest
Stanislaus National
0
Region
5
o
0
o
O
2
CONTRACT
PAYMENT
ESTIMATE
AND
Stanislaus National
INVOICE
Forest
4/17/85
COMFORT
STATIONS
INC.
46-9B66-2-72
Belcampo
Estimate
Cut Off
Construction
No
Co.
Example
4-17-85
Date
Contract
Amount
Original
Increase
or Decrease
New
Contract
$
$
$
Amount
84840.00
5000.00
89840.00
Used
Used
Time
Funds
50
73
%
%
-----------been
RRRkkkRRRRRRRRRkRRRRRRRRkkkRRRRRRRRRRRRRRkRRRRRR
I certify that the amount listed
Total
Earned
$
65355.00
is
correct
and
has
payment
not
been
received.
R
contractors
All
Previous
Payments
$
date
rep
.0
----------k
----------Above
and
items
payment
contracting
have
is
been
received
Amount
officers
is
Contracting
$
6535.50
$
58819.50
date
rep
DUE
Payment
Retained
recommended.
THIS
ESTIMATE
approved.
Officer
date
R
REMARKS
This
pay
estimate
is
an
example
only.
------01900
---------------------------------------------------------------------------ITEM
NO
ITEM
DESCRIPTION
AMOUNT
UNIT
PRICE
QUANTITY
-----------------------------------
Mobilization
LS
8500.00
1.00
8500.00
02110
Demolition
EA
400.00
1.00
400.00
02111
Removal
EA
400.00
1.00
400.00
13610
Vault
of
Toilet
Existing
Structures
18685.00
EA
Building
3.00
56055.00
---------------------------------------------------------------------------CUMULATIVE
TOTAL
65355.00
Kiýfiýtjýi$S.vi
isYý4ifiýývirii.4
ýp
nkriiJ.%i$ýSriYiritti$ý.ýiti.rt.Iff
irý
...fr.ýitýý.ýý.n...2..ýE..tr............ý.ý n..
ýý
Figure
1.--Sample contract
payment
.
rl
C.i..
tt..2ý%ý..i6ý..
estimate and
3
Fýy
-i
tint
invoice.
ý
ý9.
6o-.Y.Gýýi.f..
.
.
ý..cýLn..
i6
.S.ý.o
.
k4.
..n9
ýp.
. C.
...
COST-TO-GOVERNMENT
REPORT
Stanislaus National Forest
4/17/85
COMFORT STATIONS
INC.
46-9B66-2-72
Belcampo Construction Co.
No
Report
1
Construction
Total
Began
7/26/84
Days Allowed
Extension Days
Available
Days
Days
Used
Time
Funds
Used
Used
120.
20.
140.
70
50
Anticipated
Funds
DOLLAR
A
%
73
95
%
%
AMOUNTS
A
A
A
A
A
A
Original Contract
All Modifications
Present Contract
$
84840.00
5000.00
$ 89840.00
Total To
$
65355.00
$
85240.00
A
A
A
A
A
A
Date
A
A
Total Probable
A
A
A
RAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
REMARKS
This
cost-to-Government
BOB
report
is
an
example
only.
date
BADER
Engineer
Forest
----01900
--------------------------------------------------------------------------------------Q
U A N T I T I E S
A M O U N T S
UNIT
PRICE
----
-----
TODATE
------
PROB
----
LS
8500.00
1.00
1.00
1.00
02110
EA
400.00
2.00
02111
13610
EA
EA
400.00
2.00
1.00
1.00
2.00
3.00
4.00
3.00
4.00
ITEM
NO.
-------
18685.00
BID
---
BID
---
8500.00
800.00
800.00
74740.00
TODATE
PROB
------
8500.00
8500.00
400.00
1200.00
74740.00
400.00
56055.00
800.00
--------------------------------------------------------------------------------------Figure
2.--Sample cost-to-Government
report.
4
Is
the Forest Service
Ready
for Artificial
Intelligence
Dale R. Petersen
Project Evaluation
Office
Washington
Implementation
Engineer
modi-fied
If
be
title question were posed the answer might
If we asked a similar question but
the time to within 10 years the
answers
the
No.
I
I
dont
might be
hope so or
what is Artificial Intelligence
know.
AI
By
anyway
the
way
inter-pretation.
term that has broad
United States are in a
race toward the fifth-generation
computer and expert
On the other hand software packages for
systems.
microcomputers
claiming to embrace AI are now
available.
The best concept
of AI may have been
William
F.
expressed by
Zachmann vice-president of
International Data Corporation.
During his
in the May 6 1985 Computerworid
he said
believe
artificial intelligence expert systems
and software systems that aim in one way or another
to extend human mental capabilities
the way a
extends human physical capabilities
will
be
of
the
unquestionably
a very important part
future.
The same article states that expert
will soon grow at a rate of 60 percent per
year and in 5 to 10 years they will be everywhere.
It
may be
a
misunderstood
Japan and the
inter-view
bull-dozer
I
sys-tems
com-puter
lan-guage
Without
realizing it at the time I purchased
my
one software package designed to communicate
with outside data bases is considered
natural
The program
processing an element of AI.
allows quick development
of questions derived from
choice of English phrases to obtain data.
The
be
stored
for
reuse.
This is elementary
may
to be sure.
In fact AI is in its infancy
and at
the
that
same stage
computer programming was in the
1950s.
of AI incorporates
early
My understanding
natural language not S2K variety
possibly speech
recognition and information from a knowledge base.
This base is comprised of expert domain data or
rules.
For a given situation it is possible to
recall these rules to lead us through a proper
sequence or to judgment choices with certainty
ques-tions
5
a
All of this
times using graphics.
involves heuristic problem-solving
techniques
using
Classical programming
symbolic languages like LISP.
and inadequate
inefficient
languages are considered
for developing
symbolic processing applications.
factors
at
Minicom-puters
demon-stration
available for $3000 on easy-to-use software
on a microcomputer
using up to 400 rules.
handle
Each rule
can now
up to 1000 rules.
in
if-then
or
is
law rule
expert
essence an
Office Engineering has a
opinion.
Washington
diskette of Personal Consultant an expert
system.
Copies are available from Texas Instruments
to run on TI or IBM personal computers.
AI
is
TI
envision several
possibilities might be
I
could
1
applications
for AI.
Three
Use of the Forest Service Manual.
Imagine a
Forest Service Engineer wanting to know the
considerations
for selecting a new bridge site
or the process for obtaining a right-of-way.
He or she uses the speech command
asking questions relative to either a
bridge or a right-of-way that might start How
do I begin
In the
course of the computer
the
dialogue
Engineer is led to each
consideration
in the Forest Service Manual
Regional
supplement Forest supplerhent
policy letters Engineering practice
decisions and so forth until he or
she has a list of things to be done.
microcom-puter
impor-tant
FSM
consid-erations
or policies change and as work
progresses the AI program is updated and the
Engineer can check to see if there are required
changes or if anything has been overlooked.
As
conditions
situations on
Important first encountered
these projects may become data for future
It
could lead to an electronic
FSM plus.
con-siderations.
2
It may
Road Maintenance
Program.
include all of the requirements
in
and considerations conflicting
or not
into
an AI
a
road
maintenance
developing
budget
and
the
rules
making
By going through
program.
certainty judgments that could incorporate
features of tradeoff evaluation value
FSM requirements and so forth it may
be possible to create
a better
fairer budget.
It would be interesting to try.
Determining
Fe
-possible
a
to
engi-neering
6
3
consid-erations
A Ski
Lift Safety Program.
Suppose there is a
derailment.
What are all the
to be checked
before the lift is put
back into operation
We might ask our AI
that question.
We might find a number of
If this exists do this statements that may
include such things as code requirements State
laws lift history personal contacts to make
field inspection items reports to complete
operator factors weather situations and other
reminders.
This program might be a
com-puter
ski
lift
partic-ularly
discontin-uance
to try given
the
Service-wide Ski Lift Engineer
We could capture some of the
position.
expertise before he or she departs.
incum-bents
good
of
one
the
appli-cations..
These
are but some examples of possible AI
Perhaps you can think of many more.
in the Computerworld
Zachmann
article suggests
that the most important Al applications will run on
At this point I pose the
personal computers.
following possibilities as avenues that the Forest
Service might pursue to explore AI in one of the
above areas or in different areas
1
2
3
Interested users in the Forest Service might
buy some of the AI microcomputer
packages on
It
does not
the market and try an application.
have to be grandiose for starters.
In fact
the
smaller and simpler the better are the
chances for getting
started.
Any results
should be shared Service-wide.
Let Forest
Service Research
explore what is in
and recommend Forest Service
marketplace
that are most cost effective.
If
applications
appropriate Research might even develop some
applications.
the
Chief and Staff might determine how important
AI is for the future.
They in turn might
charter a group to determine how big an AI
program should be and at what rate it should be
pursued and for what priorities.
if the
Forest Service does pursue AI soon
Perhaps
we will be able to say
to the
question Is
the Forest Service ready for Artificial
Yes
Intelligence
7
Slave Your Old
Demand Terminal
Serial Printer to a
D41 0 Video
Wayne
Civil
T.
The
of
or
to
Data General Dasher
Display Terminal
Beddes
Engineer
Ray
Computer
4
Region
L.
or
Flinn
Systems
Engineering
Programmer Systems
Engineering
purpose of this article is to increase awareness
terminal
potential to use a surplus hard-copy
an RS-232-compatible
printer as a slave printer
the Data General Dasher D410 display terminal.
the
Are you currently using a Data General video terminal
with no convenient
means to print
Are you walking
long distances to your letter-quality printer when
all you really wanted was a simple screen dump
If
terminal that is collecting
you have an old hard-copy
dust why not slave it to the video terminal to
screen dumps or to print anything
accomplish
on the screen
To accomplish
this you need
one more item in addition to your hard-copy
terminal
or serial printer--you must obtain
or construct
a
printer port cable shown in figure 1.
dis-played
The slave printer attaches to the female 9-pin cannon
connector
on the rear of the D410 terminal.
When
terminal to the
you attach the printer or hard-copy
D410 make sure that the baud rates are the same by
setting the printer DIP switches on the rear of the
D410 according
to table 1.
Table
l.--Baud rates.
Baud
Switches
rate
192000
9600
4800
2400
1200
600
300
110
9
4
2
3
1
1
1
1
1
0
1
0
1
1
0
0
0
1
1
0
1
0
0
0
1
0
0
0
25-Pin
2
1
14
4
3
15
916
6
5
17 18
8
7
19
20
9
21
10
Cannon
11
12
22
23 24
9-Pin
Cannon
13
25
Shielded
Communications
Cable
2
1
6
3 4 5
7
8
9
Figure 1.--Printer
port cable.
construct
the printer port cable
you will need a
male 9-pin cannon connector 5 to 6 feet of shielded
4-conductor
communications
cable and a male or
female 25-pin cannon connector
commonly referred to
as an RS-232 plug.
According to the RS-232
remote terminals should have a male connector
but check your particular device since not all do.
To
stan-dard
connec-tor
Jump pins 6 8 and 20 together and pins 4 and 5
together on the 25-pin connector then connect
pin 8
of the
to pin 9 of the 9-pin
25-pin connector
pin 7 to pin 2 pin 3 to pin 7 and pin 2 to
Refer to figure 1 or to your Dasher D410 and
pin 8.
D460 display terminals users manual.
10
terminal or printer attached
to the D410
the
LOCAL PRINT key to print the contents of
depress
the
This will home the cursor and then print
screen.
on
the screen from the
cursor on down.
If
everything
Electronic Office
you try to print a Comprehensive
screen and the cursor is trapped inside a screen
window preventing
the entire
you from printing
screen you may negate the screen window by taking
the
terminal offline.
To take the
terminal offline
depress CMD-ON LINE and then depress CMD-BREAK ESC
FB000.
Put the terminal back online and continue
your screen dump in the normal way.
With
the
When you want to print more than one screen put the
D410 in print passthrough
mode and you can direct
all output that would
ordinarily go to the screen to
the printer.
To engage the print passthrough
mode
take the terminal offline simultaneously
depress
the CMD and BREAK ESC keys then sequentially
depress
F
3
ALPHA LOCK must be on.
The cursor will
from the screen indicating that print
is engaged.
Put the D410 back online and
execute Command Line Interpreter commands such as
TYPE or FILESTATUS.
When you are finished with the
printer disengage the print passthrough
by taking
the
terminal offline and depressing CMD-BREAK ESC
F
2.
If you want to execute print passthrough
without
taking the terminal offline write a BASIC
to engage print
program such as the following
dis-appear
pass-through
passthrough
10
20
Use
the
10
20
print chr
end
30chr$70chr$96
following
print
end
to
disengage
chr$30chr70chr$97
Alternatively use a FORTRAN
engage print passthrough
PRINT
END
Use
the
program
such
as
this to
036106140
following
FORTRAN
passthrough
PRINT
END
print passthrough
program
to
disengage
print
036106141
Engage and disengage
the programs.
11
print passthrough
by executing
The hard-copy
terminals require that you change the
terminal characteristics
so the
host will send
Do this by
carriage returns in place of new lines.
typing the Command Line Interpreter command
CHAR/NAS.
When you are finished with the printer
reset the terminal characteristics
by typing the
Command Line Interpreter command CHAR/RESET.
If
you would like further information contact Wayne
Beddes FTS 586-5200 or Ray Flinn FTS 586-5199.
12
Aerial
Photography
Determination
Dave Wolf
Assistant
Region
BACKGROUND
Geometronics
Flight Altitude
Leader
2
preci-sion
tol-erance
When obtaining
other purposes
aerial photography
for mapping or
requiring measurements
using
stereoplotters it is necessary to control the
altitude of the aircraft above sea level within
fairly close tolerances.
Region 2 specifies a
of
5 percent
of the nominal flight height
above the ground with a minimum tolerance
of 100
feet for flight heights less than 2000 feet.
For various reasons much of the mapping photography
procured
by Region 2 actually is taken at altitudes
that exceed this specification.
However such
may still be usable maps or measurements
derived from photography
taken at too high an
will be less likely to meet its accuracy
Because flying seasons are short and
waiting for replacement photography
may cause delays
of up to a year it is often desirable to accept the
out-of-specification
photography
along with the
risks associated with its use.
pho-tography
alti-tude
speci-fications.
Because it is difficult to apply a monetary value to
this increased risk Region
2
aerial photography
in
specifications
arbitrarily allow for a reduction
payment of 10 percent for each whole altitude
increment or portion thereof that the actual
flight altitude exceeds the specified altitude plus
tolerance up to a maximum payment reduction of
50
For example if the specified altitude
percent.
for a flight was 11000 feet
and it was
100 feet
actually flown at 11425 feet there could be a
40 percent reduction
in payment for that flight
100
325/100
11000
11100 11425 - 11100
40 percent.
Because
3.25 round up to 4 x 10
contract
payment can depend upon the determination
of the
actual flight altitude
it is extremely
as
important that it be computed as accurately
possible.
toler-ance
13
THEORY
The
flight
altitude
H
is
equation
S
computed
from the
scale
1
f
H
-
h
or
S
f
h
S
where
f
the
S
the
camera
photo
elevation
focal
scale
length
at
a
particular
terrain
h.
The
The camera focal length f is always known.
scale S can be determined
by measuring the photo
distance between two points whose ground position
from a
has been surveyed or can be determined
the
40
within
feet.
Ordinarily
72-minute quad
elevations of points on a photograph are known from
ground surveys or can be estimated within 20 feet or
less from U.S. Geological Survey 72-minute quads
Unfortunately a photo
40-foot contour interval.
scale and ultimately the flight altitude
in this manner will be accurate
only if the
With
same elevation.
two points used have the
Forest Service large-scale mapping photography
to find two points at any
it is often difficult
that are identifiable on both a photo and a
map much less two that have the same elevation.
Even if surveyed targeted points are available and
two fall on a single photo it is likely that they
will have different elevations.
com-puted
typi-cal
ele-vation
from points with
The error in photo scale determined
different elevations relates to the fact that the
location of a point on a photo with a fixed ground
position varies with its elevation and its position
relative to the photo nadir.
The nadir or ground
below
the
can be assumed to
camera
point directly
to the photo center
as indicated by
be equivalent
for near-vertical mapping photography.
the fiducials
As
The term photo center will be used hereafter.
increase
in
are
they
displaced
points
elevation
Figure 1
radially outward from the photo center.
illustrates this effect and the effect on the photo
14
/
/
O/
- - - -
Photo
Center
Radial
line
Point
O
Figure l.--The effect
of
A
from photo
elevation
center
2000feet
B.C
Points
Elevation
1000
feet
Q
Elevation
I500feet
Q
Elevation
2000
elevation
change
on
feet
photo
15
distance.
distance
between
position
fixed
point A fixed and
elevation varies.
points
B
and
C
dis-tance
Figure 1 shows how the effect of elevation change on
photo distance depends on the location of two points
As
relative to the photo center and to each other.
the
elevation of point C increases the photo
The photo distance
to point A also increases.
from point B to point A shortens as point B rises
from 1000 to 1500 feet then lengthens as point B
rises to 2000 feet.
The true photo scale at
feet
could
be computed from the photo
2000
distance to point A from either points B or C at
elevation 2000 feet.
The true scale at any known
datum could not be determined directly using point A
and points B or C at elevation 1000 or 1500 feet.
eleva-tion
Figure 2 illustrates the geometry of the effect of
elevation change on photo point location.
Using
similar triangles it can be shown that
r
r
-
2
H-E
H-E
flight altitude H that is specified
and with elevations h and
known a new
radial distance at h is computed by measuring the
radial distance of a point on a photo.
Then the
new location of the point at radial distance r is
plotted and the photo distance measured to another
The altitude is computed
point at elevation h.
If this altitude
agrees
using the scale equation.
limits
with the assumed value within acceptable
that is within 20 percent of the specified flight
altitude tolerance then this altitude is accepted
otherwise the process is repeated.
for
PROCEDURE
FLIGHT ALTITUDE
DETERMINATION
Assuming
PRACTICAL
APPLICATION
A
altitude
a
h
square piece of matte drafting film is
lines parallel to
prepared with two perpendicular
see
the edges and intersecting at the center
The overlay is placed over a print or
figure 3.
air photo and taped so
the negative of the pertinent
that the lines intersect the four side fiducials
diagonal lines could be used with corner fiducials.
The intersection of the lines indicates the photo
center.
Two points are selected for photo scale
determination and the ground distance between them
is noted.
The radial distance r to the low point A
The high
is measured
to the nearest 0.01 inch.
point B could just as well be used but for
consistency the low point is always used.
10-inch
16
rk
h---
h--
h
Elevation
h
H
Figure
2.--The
effect
Elevation
Flight
of
--J
A
Point
A above sea
of point B above
altitude above
r
Radial
distance
r
Radial
distance
of
---ý--I
elevation
sea
of point
on
level
level
A
of point
change
sea
level
A
at elevation
h
photo point location.
17
Photo
i
lai
B
Overlay
i
I
i
e
i
1
1
m
I
r
A
1
I
r
I
e
AO
I
r
B
A
Figure
3.--Determining
the
photo center and
High
point
Low
point
flight
18
altitude.
2
is used to calculate
the radial
Equation
distance r at the elevation of point B.
Using a
scale aligned with the photo center and point
a
is marked on the overlay
point
at the
new radial
distance.
This point is the photo location of
point A if it were at the same elevation as point B.
The photo distance
is measured between
and B and
is used to compute
the
altitude
flight
using
This value is compared with the flight
equation 1.
altitude assumed for use in equation 2.
And if the
value is not acceptable a new radial distance r is
computed using this flight altitude and the process
is repeated.
A
A
A
HAND CALCULATOR
PROGRAM
endorse-ment
The following
program was
Hewlett-Packard
41C.
The
of this calculator.
Storage
00-04
for use
developed
author intends no
in a
Registers
Work registers
Nominal camera focal length f feet
Ground distance D between 2 points feet
Flight altitude convergence
test value T
05
06
07
feet
Registers 05 and 07 are loaded once for a photo
project with a single camera and altitude tolerance
register 06 is loaded at the beginning of each
problem.
Command
LBL
Comments
and
in
inches
to
FLTALT
R/S
Run
Instructions
1
radial distance r
low point press ENTER
elevation h feet of low point
press ENTER
elevation h feet of high point
press ENTER
estimated flight altitude H
press R/S
Key
2
3
4
feet
STO
01
Estimated H
02
h
03
h
in
register
RDN
STO
in
register
02
RDN
STO
in
19
register
03
01
Command
Comments
Run
and
Instructions
contd
RDN
12
Convert
/
r
STO
04
LBL
AGAIN
RCL
01
Begin
RCL
03
h
RCL
01
Estimated H
RCL
02
h
r
in
feet
to
register
04
equation
2
r feet
/
12
R/S
Convert
to
Display
key in photo
press R/S
inches
r
inches
distance
in
12
/
Convert
1/X
Begin
RCL
06
RCL
05
f
RCL
02
h
00
feet
photo
scale
scale
1/S
computation
D
Photo
STO
to
Calculated
H
Calculated
H
20
to
begin
register
equation
00
1
Command
Comments
RCL
Estimated H
01
ABS
and
Difference
calculated
Run
between
07
T
X
Y
Is
GTO
CONVRG
Yes
RCL
00
No
RCL
04
Recall
r
Repeat
equation
GTO AGAIN
T
calculated
CONVRG
RCL
00
Display
GTO
FLTALT
Return
21
H
and
difference
larger than
LBL
estimated
H
RCL
@
contd
Instructions
H
is
new
2
final H
for new
problem
estimate
Metal Open-Top Drainage Structure
Flying
W
Study
Ellen Lafayette
Civil Engineer
Ochoco National
Region 6
HISTORY
Forest
drain-dips
National
Forest has tried several methods
We have
surface
water on roads.
eliminating
tried insloping outsloping wood open-tops
and drivable waterbars.
Their effectiveness
10 percent.
The
is limited on grades exceeding
Willowa-Whitman
National
Forest has used an open-top
This
drainage structure made of guardrail metal.
structure functions well but requires a concrete
base and excavation
equipment to the site.
The
Ochoco
of
W
con-figuration
Forest Road Crew Foreman
Leroy Burk Ochoco National
the
of
the
use
suggested
Flying
guardrail
and a series of long anchor pins to hold
the structure
in place
Two such
see figure 1.
have
been
installed
on
the
Spanish Peak
structures
road on the Ochoco National
Forest and have been
functioning well for some time.
Coral Sales Company in Clackamas
information
on different guardrail
Oregon provided
and
their
The Flying
availability.
configurations
but the
type guardrail is no longer manufactured
for
hand
Coral Sales Company does keep it on
scrap
metal.
Doug
Daniels
of
the
W
1984
crew installed three
three-person
Flying
open-tops on timber sale roads of various
Installation took half an
grades and conditions.
hour and only required hand tools.
The grades ranged
10
14
favorable
from
to
percent
percent sustained
adverse.
crushed
Surfacing types were
aggregate and
native.
Two of the installations had some clays in
the
subgrade that were pumping.
In
June
W
a
of an installed
Figures 2 through 5 are photographs
skew and
illustrate
the
drainage structure.
They
the
road
of
the
of
type
surfacing
interception
surface water the need for some type of filislope
23
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ýi
r
/
1
ýýý
r
ýrlfJyi
i
Ir
f
ll
flrýý
ýlýfi.ýrý
i5X
rGlýf.
yYl
r
$
J.i
rl
ý.tti
tai
ýet-ýrlýY
rý
ýýtiýlýýtr
32
1
f1f
iiftf
ýr
ý
it
J
ri
i
ir
GI
t
.
Ir
rpi
y.r.J
tý.ý.
Pins
Anchor
r
XW
11
2
411
I
11
2
1
11
04
I
2
2
II
11
15
11
Figure
W
metal
open-topdrainagestructure.
Ylfýýýtjýyý
ýIytjýfsf
3ýiý
ý..ý%it74S.rý
backfill
surface
running
týrfJrtiýýý7r1
611
existing
with
flush
411
1.--Flying
open-top
metal
Install
4V
Method
Plan
of
Installation
View
Edge
of
Road
7
18
Qiiii
e
Anchor Pins
f
c
ý
ý i
ýý
J
Eri
Y
ýý
i
C
41
t
i.
.tiff
yw
viiyr7
i
Downgrade
Install
flying
lengths
shown
Refer
to
the
W
on
end
at
open-tops
the drainage
view
for
locations
the
skews and
listing.
specific
and
configuration
dimensions.
8
x
have
flush
18
anchor
with
EDP
Figure
1.
pins
maximum spacing
a
cont.--Flying
W
the
wings
as
staggered
of 4 feet.
as
shown
shown
Skew
Diagram
open-top
drainage
25
shall
BOP
11200
metal
above
They shall be
in the end view.
60
structure.
driven
Figure
2.--Skew
and
type
of
road
t4
surface.
I.4tn
ire
Figure
3.--Interception
of road
surface
water.
IC
N
J
ý
ý
7lý
ý1E
Lý
ý
t
Figure 4.--Need
for
fillslope
Figure 5.--End view of Flying
showing the effect of log haul
bladed road.
protection.
26
W
configuration
on
the
freshly
protection
and
effect
tracking
bladed road.
TEST
EVALUATIONS
We
1
2
3
4
5
The
an end view that also shows the
that the log haul has on the freshly
had anticipated
Guardrail
Weld
the
following
problems
buckling.
failing.
Plugging.
Grades
hooking.
Anchor
pins pulling
haul
out.
installations varied from
to 2 million board feet from
June 6 through October 26 1984.
The installation
Of the five problems anticipated
performed well.
It occurred
on aggregate
only plugging occurred.
roads where the truck traffic tracked aggregate into
the
installation.
Material tended to accumulate
where the drift pins were placed in the trough.
over
the
200000 board feet
From the
limited testing we anticipate
that the
plugging can be minimized by installing the drift
the
skew
pins only in the flanges and by decreasing
angle to a maximum of 60 degrees from the centerline.
Energy dissipators rock aprons at the outlets also
in erosive soils.
Maintenance
is
are recommended
simple material can be removed during hauling or
grading operations.
in-stallations
The
test
locations
tested.
COSTS for
MANUFACTURING
the
FLYING
CONFIGURATION
in cohesive
soils
soils have not yet been
all
W
use of the Flying
guardrail requires
used or reconditioned
material because
purchasing
the configuration
no longer
is commonly made.
Normally however used material cannot be specified
in Forest Service contracts.
One solution to this
problem is for the Government to supply the
An independent
is interested
in
manufacturer
fabricating the product if there is enough interest.
The
W
were
in granular
mate-rial.
Workman
$
Sons of Prineville Oregon has provided
the following
of
information for the manufacturing
the
Flying
There
would
$25000
to
W
configuration.
be
an initial one-time
$30000 for tooling
27
up.
only cost of
The company
recover this in the first year for the
for them.
After
cost effective
project
would
be
linear
foot.
costs
$3.75
per
tooling up
If 5000 feet were ordered in the first year the
costs would be $8.75 to $9.75 per linear foot
$3.75 per linear foot for materials fabrication
and profit $5.00 to $6.00 per linear foot for
After the first year costs would
tooling up.
to
$3.75
drop
per linear foot.
would
have
to
to
be
demand develops
the
would be
specifications
materials see
changed to contractor-furnished
figure 7 for sample Special Project Specification
If
Cost
Comparison
649.
The following
installation costs reflect the cost of
materials from Coral Sales and the cost of using a
The
force account
crew for the installation work.
costs would increase if costed to comply with the
The compaction
attached
and drawings.
specification
method in the specification
would require
The rest of the equipment required to
tamper.
structure would remain the same.
install the open-top
a.mechan-ical
The
cost
Flying
of
W
metal drainage structure
are
guardrail configuration
a
using
as
Material 18 feet $2.40/LF
$1.80
Fabrication Cost
Anchor Pins
Installation allow 1 hour for
3
laborers with shovels this
includes moves between site
Pickup with trailer
Total
costs gives
Adding maintenance
which is $7.50 per linear foot.
CONCLUSION
a
total of
the
follows
$50.00
5.00
52.00
25.00
$132.00
$135.00
W
The Flying
has proven to be a
configuration
cost-effective
drainage installation.
Important
features are low material cost low installation
cost minimal equipment and ease of maintenance.
The Ochoco National
Forest is including these
installations in contracts
on local roads where
8 percent.
drainage is required on grades exceeding
At present the Flying
guardrail is Government
furnished.
To eliminate the effect on Forest funds
we hope to correct that situation.
W
interested in further information on the
can contact Ellen Lafayette Ochoco
Flying
National
Forest at 503 446-6247.
Readers
W
28
SPECIAL
Section
649
METAL
-
PROJECT SPECIFICATION
OPEN-TOP DRAINAGE
STRUCTURE
GUARDRAIL
TYPE
DESCRIPTION
of installing metal
649.01.
This
work shall consist
open-top drainage
with these specifications and in reasonable
structures in accordance
close
ON THE DRAWINGS.
conformity with the lines and grades SHOWN
This
work includes
all excavation
bedding and backfill
required to
the
anchor
Installation also includes furnishing
complete the work.
and welding
of sections.
pins and any necessary cutting
MATERIALS
649.02.
guardrail
Drainage structure material shall
furnished by the Government.
be
standard
metal
beam
Anchor pins.
Anchor pins shall be galvanized
or zinc-coated
Anchor pins
and may be round
or rectangular cross-section.
be a minimum 5/8-inch diameter x 18
inches
long with a
1-1/8-inch diameter head and used with a 1-1/2-inch diameter washer.
649.03.
steel
shall
CONSTRUCTION
REQUIREMENTS
649.04.
Installation.
The metal
structures shall
open-top drainage
be-installed
at the locations and to the lines
and grades
SHOWN ON THE
and staked
on the ground.
Guardrail shall be cut and spliced
DRAWINGS
as needed
to provide continuous
at
each
drainage structures
with Section
555 and as
Welding shall be done in accordance
SHOWN
ON THE DRAWINGS.
installa-tion.
re-quirements
649.05.
of
649.06.
-
Excavation
Excavation.
-
Section
The
Bedding.
uniform density
shall
be
in
accordance
bedding
the
throughout
provide
shall
length
of
the
Backfilling.
or backfilled
approved
by
i44YrOý..yi1rý.i4
-4iqq4ti4..frvý.Qýýn4i.
w.v.4..LS.ag.....
Figure
7.--Sample Special
Project
the
a firm foundation
structure.
64907.
Anchor pins shall be placed as
Anchoring.
Alternative anchoring devices may be used
DRAWINGS.
writing by the Engineer.
649.08.
be placed
have
been
with
206A.
..
Metal
A.
ir
.
4ýiC.....
YA
4i
44..
ii..n.ti.y
specification.
29
p.
SHOWN ON THE
if approved
in
drainage structures shall not
and bedding
excavation
open-top
until
the
structure
the Engineer.
v.
of
lv
i
/
back-fill
After bedding is prepared
and the drainage
structure is placed the
excavated area around
the structure shall be backfilled with suitable
inches
in
diameter.
The
granular material not exceeding 1-1/2
material shall be of a moisture content
suitable for effective
compaction and shall be compacted with a mechanical tamper until
visual
ceases.
displacement
METHOD
649.09.
OF-TEEMS
The
and
649.10.
The
Pay
MEASUREMENT
method of measurement will be DESIGNATED
measured in accordance
with Section
106.
BASIS
Section
106
SCHEDULE
OF
OF
OF
in
for in accordance
accepted
quantities will be paid
contract unit price for each pay item shown
at the
ITEMS.
Install
Metal
Open-Top Drainage Structure
Government-Furnished Materials ...................
with
in
the
Pay
Unit
Linear
Foot
Install
Metal
Open-Top Drainage Structure
Government-Furnished Materials ..........................
Each
it
64902
SCHEDULE
PAYMENT
Item
64901
the
Figure
7.
cont.--Sample
Special
Project
Specification.
30
H
P_
41 Road Data
41 RDADS
Design System
Dan McReynolds
Randy Warbington
Civil Engineers
Chattahoochee-Oconee
National Forests
8
Region
INTRODUCTION
This article describes a collection of calculator
and computer programs that were developed
on the
Chattahoochee-Oconee
National
Forests for use in
staking out route locations collecting survey data
and field designing
Forest roads.
The program
can be used either as electronic
input to RDS
or as final design quantity
and slope-stake
on whether
depending
the design
is performed
on the UNIVAC
mainframe or entirely on the HP-41 and
Data General equipment.
The system consists of the
out-puts
print-outs
following
1
2
3
4
HP-41 programs that provide information and
assistance in staking out route locations and
that store the collected survey data.
HP-41 programs that assist the user in field
designing low-cost Forest roads calculate and
store clearing earthwork and seeding
and provide
slope-stake data.
quan-tities
de-vice
HP-41 programs that
to another.
Programs that
run on
transfer
Data
data
General
from one
equipment
and
Cen-ter
b
either
a
Format the collected survey data for
transmission to Fort Collins Computer
FCCC for subsequent use by RDS
or
earth-work
Provide
an
output
surfacing
with
clearing
seeding quantities
and
slope-stake and grade information for
Forest roads.
field-designed
31
and
The system reflects the types of survey and design
methods we currently use on the Chattahoochee-Oconee
is described by the
Forests.
The procedure
National
in
1.
flow chart
figure
The
following
programs that
is
are
list
a
and
currently
brief description of
part of this system
the
Provides centerline
stationing and minimum
selection
of curves by choosing
lane width allows
radius tangent or external calculates maximum
radius curves fitting between two points of
provides information for staking out
centerline stations circular curves and collects
and
stores RDS card type 16 data.
Figure 2
the
use
of
this
illustrates
program.
HP-41 PROGRAMS
STA.
inter-section
road
Will
or
RDS
Level
1.
C
and Difficult
Centerline
program.
2.
D
terrain Level
with
is staked
CT 16 data
are
STA
stored.
Field Design
Favorable terrain Level
1.
and profile data are
Cross-section
taken with XSECT program and CT
52 data are stored.
2.
dumped into Data
equipment and transmitted
3.
3.
Data
4.
Road
using
5.
be field-designed
be used
will RDS
Road
are
is
designed
on
UNIVAC
to
FCCC.
with STA
is staked
is
not
This
step
program.
where
in
terrain
necessary
free-flowing alignment will
work.
Centerline
Road is designed and slope
staked in field using
BALANCE program.
Data are dumped into Data
General computer for output
information
with slope-stake
and quantities.
mainframe
RDS.
is
slope
staked.
Plans
Figure
General
1.--Procedures
for
determining
and contract
document
are completed.
route
locations.
32
D
1
Pti
p
p0
p
P
91
ýpý0
F
ýý
Fy
I
o
Pti
O
00
Not
LOC.
scale
to
CALCULATOR
USER
INPUTS
CALCULATOR
RESPONDS
COMMENTS
15.00
30.00
0.00
5.00
80.91
STA80.91
AZ
R/S
80.00
USER
NEEDS
STAKES
PI
AZ
PROMPT
DELTAR75.00
EX
R/S
R/S
R/S
40.00
DEG109.54
MUST
RESPOND
PROMPTS
A
B
G
TRUCK
L1
TRUCK
L2
BEG STA
BEG AZ
DIST
DIST
TANG
RAD
TAN
IS
TANG
OK
EX13.58
LC68.24
RAD52.13
MIN WID19.58
PI80.91
PC40.91
EX75.03
V
C
D
E
DIST
POC
TO
SET
FROM
SET
PT109.15
XEQ POC
95.00
75.03
SC19.85
AZ53.2835
F
G
POC
DIST
DIST
AZ
TAN
RAD
IS
TANG
TO
SETH
40.1
STA149.25
R/S
340.00
DELTAL100
RIS
52.13
OK
EX28. 97
LC90. 98
RAD52. 13
MIN
WID23.90
PI149.25
V
PC87.12
EX132.61
PT178.11
STA208.11
I
K
Figure
DIST
2.--Staking centerline with
USER
SETS
POC
NO MORE
POCs
USER
SETS
PI
NEEDS
AZ PROMPT
TANG62.13
DEG109.54
H
J
R/S
PC
USER
SETS
USER
SETS
EX
USER
SETS
PT
TO SET
POC
30.00
41-RDADS
STA
program.
33
USER
USER
USER
SETS
SETS
PC
EX
SETS
PROCEED
PT
AS
ABOVE
Assists in field design of Forest roads
sidehill templateon
self-balanced
provides
bench
or
a
template on steep
sideslopes
allows for user-input limits such as maximum
vertical
cuts and daylight extensions allows
centerline
cut/fills provides finished road
and
adjusted net mass in field provides slope
grade
stake and clearing flag information and stores data
necessary for computing clearing earthwork
and seeding quantities.
Figure 4
the use of this program.
BALANCE.
a
user-input
sur-facing
illus-trates
Transfers data
DUMPEM.
to HP cassette
tape.
XDUMP.
from HP
from HP-41
extended
Transfers
cross-section and profile data
cassette tape to Data General AOS file.
retrace data
Transfers
centerline
RDUMP.
cassette tape to Data General AOS file.
BDUMP.
General
DATA GENERAL
PROGRAMS
memory
Transfers
AOS file.
BALANCE
data
from HP
from cassette
Data
to
mas-te
and were
programs are written in BASIC
National
Chattahoochee-Oconee
the
on
developed
the
41CV
executed
from
all
Forests.
They are
the
in
CLI
which
written
by
was
program
in
Group
Region
Engineering Computer Applications
the
Forests.
and modified by
These
8
commu-nications
commu-nications
Reformats card type 16 data for RDS
2780
a file for transmission via
to FCCC.
RETRACEFMT.
and sets up
CROSSFMT.
Reformats card type 52 data for RDS
and sets up a file for transmission via 2780
to FCCC.
use
use
BALANCE.
Computes clearing earthwork surfacing
and seeding quantities produces formatted output of
field book information staked road characteristics
quantities and slope stake data for field-designed
roads.
Figure 5 shows a sample output from this
program.
34
III
pro-file
shal-low
side-slopes
XSECT.
Collects and stores cross-section and
data RDS card type 52.
Figure 3 illustrates
the use of this program.
Turn
point
E
2
16
4
A
3rL
G
B
0
C
Station
-32
-95
10
Rod
5430
1
3
Ahead
Reading
D_
Same
s1
for
ope
20
LOCATION
CALCULATOR
A
SD.SHT.R/D
SHT.AHD.ROD
LT.SO.1ST
STATION
B
L
EARLIER
ROD
DIST
ROD
L
DIST
L
ROD
C
D
USER
INPUTS
PROMPTS
DIST
OF
Y
Y
Y
154.30
-3.2
F
G
20
99
SS
20
16.2
34
-99
2.3
NEXT
Figure
3.--Recording
R/S
R/S
STORE
Y
STATION
A
cross-section
and
RIGHT
SIDE
TN
LAST
AT
12
R/S
3.7
R/S
R/S
R/S
R/S
R/S
TO
SIDE
error
1
R/S
R/S
-32.010
O.K.
LEFT
-9.4
ROD
R
DIST
ROD
R
ROD
R
DIST
R
ROD
ROD AHEAD
O.K TO STORE
E
CALCULATOR
RESPONDS
profile data
35
with
41-RDADS.
6
PTS
STA154.30
AHEAD3.70
9900.020
-94.020
-32.001
-32.010
0.000
99162.034
23.012
STORED
PT
STA
C
1
.
1
5430
I
.4
10.14
2.47
A
8
D
CALCULATOR
LOCATION
EARLIER
CUT
SLP
/1
/1
0.75
1.5
40
FILLSLP
Z
SHRINK
MAX VRT
CUT
AD.
V CT
CLR
AD. S CT CLR
ADD.
FIL CLR
TOTAL
WIDTH
TO CUT
W/2
A
STATION
AB
CL
Z
5
3
3
0
14
8
154.30
28
SIDESLOPE7
C/F
R/S
line above
to
user
hits R/S
could also input his own CL cut
R/S
R/S
NOTE
On
B
C
D
R/S
A
R/S
R/S
Z
NEXT
AHEAD
CALCULATOR
RESPONDS
USER
INPUTS
PROMPTS
CUT2.47
self-balance.
or
He
fill.
DIST8.00
VERT
CUT
S11.42
F10.14
CL
C/F0.23
X R.GRD6.19
9
O.K.
TO
STORE
R/S
O.K.
TO
STORE
Y
UP
TO
154.30
MASS0.00
STORED
STATION
A
NOTE
The
section
shown
above
is
a
normal
sidehill
section
with
a
cut.
It
is
also possible to have
sidehill
section
with
a
a
cut
a
full
bench
and a through
sloped cut
section a through
section
fill section.
of these
sections
Examples
follow.
vertical
Figure
4.--Designing
and
slope
staking
with
41-RDADS
36
BALANCE program.
Daylights
to
Cut is sloped
if higher than
vert.
max.
cut
10
up
Extra Clearing
FULL
BENCH
Road
Width
10
10
I
Same
as
uphill
clearing
Cut
is
always
THROUGH
sloped
CUT
I
10
to
__
daylight
4.
I
1
Additional
THROUGH
4.
Figure
program.
cont.--Designing
and
slope
staking
with
37
Fill
FILL
41-RDADS
BALANCE
Clearing
CONCLUSION
slope-staking
The implementation of this system has resulted in a
and
substantial
savings in survey design
National
cost on the Chattahoochee-Oconee
Forests.
It has many details that are not possible
to explain in a short article such as this.
a
users manual is available that describes
the programs in greater detail.
Readers who have
further questions or who are interested in
the system on their Forests should contact
Dan McReynolds or Randy Warbington
at
National Forests 508 Oak Street Gainesville
the phone number is 404 536-0541.
Georgia 30501
How-ever
imple-menting
Chattahoochee-Oconee
38
ROCK
CREEK
124-B
ROAD
2/25/85
NOTEBOOK
STATION
GROUND EL.
.0
500.00
503.51
58.50
104.00
147.50
200.00
498.05
501.97
504.07
504.07
250.00
WIDTH
ROAD
SURVEYED
SURVEY
NAME
12.0
12.0
.
DATE
TOTAL
STAKE
.
-1.7
6.9
1.9
1.1
40
SLOPE
FILL CLEARING
ADD.
ADD.
VT.
CUT CLRG
CLRG
ADD.
SL. CUT
0
ENDING STATION
CREEK
6.0
6.0
1.5
.7
CUT
124-B
ROAD
0
3
3.0
250.00
2/25/85
EARTHWORK
STATION
0.00
58.50
104.00
147.50
ROAD
EL.
ROAD
GRADE
EXC.
C.Y.
EMB.
C.Y.
CUM.
EXC.
ADJ.
MASS
500.00
-0.8
69.42
3.77
4.5
51.72
58.70
-5.9
40.58
56.12
9.0
55.71
499.51
501.55
498.97
200.00
503.71
250.00
503.90
0.4
EARTHWORK
TOTAL
Figure 5.--Output
from
Data
General
37.88
121.14
10.21
161.72
-21.56
217.63
7.83
227.38
7.83
5.96
SUMMARY
EXCAVATION
EMBANKMENT
ADJUSTED
MASS
TOTAL
69.42
4.03
9.94
C.Y.
C.Y.
BALANCE program.
39
227.4
128.6
7.8
DIST
6.0
-10.1
8.6
11.2
5.5
FILLSLOPE
ROCK
STAKE
C/F
SUMMARY
.0
MILES
SLP
15.0
15.0
21.0
35.0
25.0
15.0
.
RLW
022585
PERCENT SHRINKAGE
BEGINNING STATION
SIDE
Z
.
4.0
-3.5
3.0
ROCKCR
124-B
BY
C/F
12.0
12.0
12.0
12.0
NOTEBOOK
HP-41
FILE
ROAD
NUMBER
CL
ROCK
CREEK
ROAD
CLEARING
STATION
CL.
0.00
WIDTH
CLEAR
AREA
CUM.
124-B
SEEDING
CLEAR
2/25/85
SEED
AREA
SEED
CUMUL.
0.030
0.027
104.00
0.057
32.76
0.037
0.032
0.119
0.023
0.142
CLEARING
SEEDING
ACRES
ACRES
AND
SEEDING
cont.--Output
from
0.022
12.00
17.33
0.034
12.00
24.58
0.041
12.00
33.33
0.044
12.00
41.67
SURFACING SUMMARY
SEEDED
CLEARED
SURFACING
TONS
SURFACING THICKNESS
INCHES
SURFACING DENSITY
TONS/CY
5.
12.00
0.003
20.00
TOTAL
TOTAL
TOTAL
9.75
0.008
0.007
20.00
250.00
TONS
0.012
0.030
200.00
SURF
0.014
27.98
147.50
WIDTH
0.003
24.23
58.50
SURF
12.00
20.00
0.030
Figure
SURFACING
AND
Data
OPTION
1
General
-
CUT
AND
.04
.14
41.67
3.00
1.5
FILL
SLOPES
BALANCE program.
40
SEEDED
Temporal Variations
Fong
L.
in
Traffic
Volumes
Ou
Development
Systems Analysis
Office
Washington
Lonnie Gary
Civil Engineering Technician
Gifford Pinchot National Forest
Region 6
Engineer
This article presents three traffic volume variation
patterns by hour of day day of week and month of
These patterns were developed
from two sets
year.
of data collected from the Mount St. Helens National
Volcanic Monument area in 1982 and 1984.
The purpose
of this presentation
is to increase
the awareness
of
volume
This
traffic
distribution over time.
aspect
is important to road
of traffic characteristics
design and management.
INTRODUCTION
criti-cal
Traffic
used to
volume is one of nine variables that are
define the traffic service level of a road
system. The others are flow vehicle types
vehicle
safety traffic management user costs
Traffic
volume has
alignment and road surface.
influence
both
on
flow and user costs.
significant
Because of its importance it has been used as a
major factor in deciding whether a road should be
FSH 7709.11.
For example
single- or double-lane
a single-lane
road should be selected if projected
traffic volumes are less than 100 vehicles per day.
On the other hand a double-lane
road should be
selected if projected
traffic volumes are greater
than 250 vehicles per day.
In cases where projected
traffic volumes fall between these two extremes
other factors
such as social or political concerns
relationship to public road systems season of use
availability of funds and traffic management are
used along with traffic volume to determine road
size.
Speed is often used as a representative of flow or
user costs.
The relationship between speed and
traffic volume has been reported in other articles
including Identifying Road Capacity and Traffic
41
Service
Level
Engineering
Field
Notes
Vol.
16
Single-Lane
1984
of One-Lane
Capacities
Turnouts Transportation Research Record
971 1984 and Family Curves for Estimating
Road Capacities
Engineering Field Notes Vol.
volume is the main
Traffic
16 July-August 1985.
concern of the present study and its relationship
with speed will not be discussed
in this report.
April-May
Road with
Evaluating
Considering a day to be 10 hours and assuming the
in 3 peak
majority of traffic to be concentrated
hours a volume of 100 vehicles per day can result
in a peak-hour
volume of more than 25 vehicles
per
hour.
If a road segment is capable
of accommodating
25 vehicles
of that road
per hour then the capacity
segment is 250 vehicles per day instead of
100 vehicles
per day.
However a road with a
per day may have peak-hour
capacity of 250 vehicles
volumes of 70 vehicles per hour.
Therefore a road
designed for 100 vehicles per day is one designed
for a maximum hourly volume of 25 vehicles per hour
or 70 vehicles
per hour in the case of a
road.
If this is true why not use 25 or
70 vehicles
per hour as a standard in selecting
roads For rural
single-lane or double-lane
AASHTO
uses the 30th highest hourly volume of
250-vehicle-per-day
high-ways
A
see
design year as the design capacity
Policy on Geometric Design for Rural Highways
However we cannot
AASHTO Washington D.C. 1965.
do so because there is not enough understanding
about traffic variation over time.
The following
discussion therefore investigates hourly daily
and monthly variations in traffic volumes.
the
SOURCE
of
DATA
Two sets of data collected from the Gifford Pinchot
The study
National
Forest were used for analysis.
area is adjacent to the Mount St. Helens National
Volcanic Monument
and is shown in figure 1.
dura-tion
The first set of data was collected from 14 study
sites from May through November
1982.
The
of data collection
for each site varied.
As
shown in table 1 half the 14 sites were single-lane
roads and half were double-lane.
Eight of the sites
were paved five were gravel and one was native.
The average
daily traffic ADT ranged from 156 to
The majority of the traffic consisted
867 vehicles.
trucks.
The road segments were not open
of logging
Most vehicles
to the public during the
study period.
were equipped with CB radios which were used to
help control the traffic.
42
ný
lIi
J
1
-8-ýy
y
ý9
I-
1
f
ý
A
ýý
l
f
ýý
r
r.
Figure 1.--Location of selected
Volcanic
Monument area.
traffic
study
43
sites
in
Mount
St.
Helens
National
of
Duration
Majority
of
Type
Number
Site
Road
number
number
of
lanes
surface
ADT
of
traffic
observation
1.--Datacharacteristics.
cable
1982
28
26-Aug.
May
trucks
Logging
713
paved
double
001
90
1982
20
4-Oct.
June
trucks
Logging
156
native
single
002
9200340
1984
15
1-Sept.
July
RVs
1033
gravel
single
007
99
1982
8
18-Nov.
June
trucks
Logging
379
paved
single
118
99
1984
15
1-Sept.
July
RVs
979
1982
9
9-Nov.
June
trucks
Logging
299
gravel
doublea
181
83
1982
22
4-Oct.
June
trucks
Logging
284
gravel
doublea
250
83
1982
9
2-Nov.
July
trucks
Logging
224
gravel
single
251
83
1982
27
10-Oct.
June
trucks
Logging
332
paved
double
267
25
1984
15
1-Sept.
July
RVs
494
1982
1982
2573
313
single
gravel
251b
Logging
trucks
Sept.
2-Nov.
6 6
1-Nov.
July
trucks
Logging
626
paved
double
303
90
1982
31
11-Oct.
May
trucks
Logging
359
paved
double
359
25
1982
6
10-Nov.
June
trucks
Logging
320b
paved
single
504
25
1982
30
5-Nov.
May
trucks
Logging
867
paved
double
706
90
1984
15
1-Sept.
July
RVs
1441
1982
8
7-Nov.
June
trucks
Logging
356
gravel
single
915
2560
1982
28
11-Aug.
June
trucks
Logging
381
paved
single
917
25
lanes.
half
a
and
one
be
to
considered
are
and
width
16-foot
to
15-
with
aRoads
traffic.
one-way
for
managed
was
flow
bTraffic
The second set of data was collected from four sites
from July 1 to September
These four sites
15 1984.
were composed of a single-lane gravel road a
single-lane paved road and two double-lane paved
Three of these four sites also had been
roads.
The
investigated in the 1982 data collection.
of
the
traffic
the
second
data
majority
during
collection was recreational with ADT ranging from
494 to 1441 vehicles
No logging traffic
per day.
traveled on the study sites during the traffic count
period.
The 1982 data were collected using induction loops
with a 16-channel
Stevens
The 1984
tape recorder.
data were collected with the Tally 74 which is an
interactive microprocessor-controlled electronic
device.
The device is capable of recording
traffic
count information on specially prepared
EPROMS a
memory module.
9
RESULTS of
ANALYSIS
varia-tions
Three
types of traffic-volume variations were
Traffic
analyzed with the collected data.
in seasons
of the year and in days of the week
from the 1982 data while hourly
were calculated
traffic patterns were derived from the 1984 data.
Season of Year.
The seasonal trend in traffic flow
for a particular
road is developed
by plotting the
roads traffic volumes according to the month of the
year.
Figure 2 presents the traffic-volume
by season of the year for the initial 14 study
sites that had different design standards.
Figure 2
indicates that four double-lane roads provided
services
for more than 500 vehicles per day in the
1982
The service volume for
timber-hauling season.
site number 706 varied from 550 vehicles per day in
The
May to 1450 vehicles per day in September.
difference in service volume at this site was more
than 150 percent.
There also was a large variation
in service
volume at site number 359.
The
in site numbers 001 and
303 were relatively
For 10 sites with traffic volume less than
small.
600
vehicles per day the ADT variations were
smaller than those of the four double-lane paved
roads.
However the monthly difference for two
numbers
118 and
sites
504 amount to 300 percent.
2
also
indicates
that high traffic volumes
Figure
occurred
in the
study area during August and
September.
varia-tions
varia-tions
Site number 002
local
a typical
is a native
road that is considered
road.
Its service volume was
45
Double-lane
1500-1400-
-------
1300
1200
road
paved
Double-lane
gravel
Single-lane
paved
Single-lane
gravel
Single
road
dirt
road
road
road
1100-1000-900
Site
800
No.
001
r
400700-706
359
600
4j
0
/10
303
500
1
.o
915
504
267
300
917
250
w
181
200
118
251
................
002
100-313
0
.................
-
Jan
Feb
Mar
Apr
June
May
Month
Figure
2.--Monthly
standards.
variation
in
traffic
volume
for
46
of
July
Aug
Sept
Oct
Nov
Year
road
segments
having
different
design
Dec
relatively stable with ADT ranging from 60 to
120 vehicles per day.
It
is important to point
out
that six single-lane roads gravel or paved each
accommodated
an ADT
of more than 250 vehicles
per
in
1982.
day
of Week.
Data from site numbers 706 267 and
were used to analyze the daily variation of
traffic movement
on a site.
Figure 3 presents three
of
traffic
for a 2-week period
histogram plots
daily
from August 8 to September 15 1982 for the three
The three sites represent three classes of
sites.
road systems--arterials collectors and local
roads.
Site number 706 is a double-lane paved
267
is a single-lane paved road and
002 a
road
dirt
road.
single-lane
Day
002
num-ber
col-lector
At both site numbers 706 and 267 weekend
traffic
volumes exceeded weekday
As
volumes.
was expected
the
variation of daily traffic volume for site
706 which is an arterial road was relatively
small compared to that of site 267 which is a
road.
Traffic
flow in arterials is more
stable than in collectors.
On the other hand the
weekend
traffic volumes for site number 002 were
than
lower
weekday
volumes which is a typical
traffic pattern for local roads.
Hour of the Day.
Hourly distributions of traffic
often
describe
volumes
the peak demands
for service
Forest
Service
on
facilities.
transportation
Figure 4 presents typical hourly distributions for a
week from Friday to Thursday on site number 706 a
The vehicles per day during
double-lane paved road.
the week ranged from 1239 vehicles
on Monday to
1598 vehicles on Sunday.
When
hourly traffic distribution patterns were
plotted in the same diagram two general patterns
for weekdays and one for weekends
see
appear--one
There were two peak-hour periods on
figure 5.
The morning and
weekdays but only one on weekends.
midday peak-hour movements on weekdays occurred from
4
to 6 a.m. and
from 11 a.m. to 3 p.m.
a.m.
However the morning peak-hour traffic
volumes were only about 50 percent of the midday
Weekend
peak-hour traffic volumes.
peak-hour
Most
occurred between 11 a.m. and 5 p.m.
peak-hour traffic on weekdays consisted of
logging-related
vehicles while approximately
of the midday peak-hour
traffic consisted of
the
respec-tively.
vol-umes
morn-ing
one-third
47
Site
DATE
DAY
SUN
8
/
8
/
8
/
9
/
8
/
10
/
WED
8
/
11
/
THU
8
/
12
/
FRI
SAT
SUN
MON
8
/
/
8
/
13
14
8
/
15
/
8
TUE
WED
/
/
8
/
16
17
8
/
18
/
THU
FRI
8
/
/
8
/
19
20
/
1982
1982
1982
SAT
8
/
21
/
1982
1982
1982
/
/
1982
1982
1982
1982
1982
1982
1982
1982
Site
SUN
MON
TUE
WED
THU
8
/
8
/
8
/
9
/
8
/
/
8
/
10
11
8
/
12
/
FRI
SAT
SUN
8
/
/
8
/
13
14
8
/
1S
/
MON
TUE
8
/
16
/
8
/
17
/
WED
THU
8
/
18
/
8
/
/
FRI
SAT
8
/
19
20
8
/
21
/
/
/
/
1982
1982
1982
1982
1982
1982
1982
1982
1982
1982
1982
1982
1982
1982
Site
SUN
8
/
8
/
MON
TUE
8
/
9
/
8
/
10
/
WED
8
11
THU
/
/
8
/
12
/
FRI
SAT
8
/
13
/
8
/
14
/
SUN
MON
8
/
15
/
8
/
16
/
TUE
8
/
17
/
WED
8
/
18
/
THU
8
/
19
/
8
/
20
/
8
/
21
/
Figure 3.--Histogram
with
Double-lane
Paved
Condition
VPD
0
MON
TUE
FRI
SAT
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
706
1982
1982
1982
1982
1982
1126
966
1077
1112
IRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRR
267
with
Single-Lane
Paved
Condition
491
308
374
371
327
I
IRRRRRR
I
002
with
Single-Lane
Dirt
306
471
647
356
370
417
418
401
578
Condition
RRRRRRR
IRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRR
1982I
1982
1982
1982
1982
1982
1982
1982
1982
plots for
960
890
1282
1263
1113
1071
1111
1113
1184
1453
IRRRRRRR
RR
42
RRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRR
IRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRR.R
daily
48
174
136
173
158
128
RRRR
45
175
175
125
110
149
82
traffic.
48
trucks
logging
were
avehicles
recreational
on
The
weekends.
traffic
of
Majority
Note
15
August
Daily
vehicles
18
16
14
12
10
a
was
site
study
paved
lane
double
road.
24
18
16
14
12
10
6
vehicles
4
8
6
2
8
4
Daily
12
14
16
18
20
22
2
1362
24
1982
August
I5
24
22
20
18
16
14
12
10
6
8
4
10
6
24
2
22
4
24
20
14
16
10
12
8
6
4
Daily
18
22
2
1302
8
1982
14
20
18
16
14
12
10
8
4
2
6
2
Forest
volume
on
site
number
706
of
Road
90
in
GiffordPinchotNational
Thursday
24
22
20
18
16
14
12
10
8
6
4
2
0
22
24
so
20
1393
100
22
1982
ISO
20
200
Wednesday
0
variations
s0
vehicles
vehicles
1239
Daily
vehicles
1512
Daily
vehicles
1598
Daily
vehicles
1372
Daily
100
TuesdayAugust
1982
August
13
Monday
1982
12.
August
Sunday
1982
SaturdayAugust
11.
1982
10
August
Friday
150
4.--Hourlytraffic
200
21
Figure
1982.
16
through
10
August
200
Recreational
Traffic
30%
Weekdays
Weekends
Daily
150
99%
traffic vehicles
---Fri 8/10/84
-...Sat 8/11/84
Sun
8/12/84
-- - Mon 8/13/84
-Tue 8/14/84
8/15/84
...... Thu
8/16/84
1372
1598
1512
1239
Wed
r
1318
1302
1362
kjF6
100
E
71
100
50
NNI
T-1
0
2
4
6
8
I
12
10
14
16
20
18
22
24
Hours
variations on
Figure 5.--Hourly traffic volume
16 1984.
National Forest August 10 through
site
50
number
706
of Road
90
in
Gifford
Pinchot
con-sisted
recreational
vehicles.
There were no morning peak
hours on weekends and most weekend
traffic
of recreational
vehicles.
The midday peak
hours for both weekdays and weekends
occurred
approximately at the same time of the day from
Traf-fic
10
a.m.
to
5
p.m.
Figures 6 7 and 8 present hourly traffic volume
variations on site numbers 267 118 and 007.
counts for these sites took place in August 1984
and included the Labor Day holiday.
Recreational
vehicles accounted
for more than 95 percent of the
total traffic.
Figure 6 indicates unusually high
traffic volume on the Monday on which Labor Day
fell.
Figures 7 and 8 show that two single-lane
roads accommodated
peak-hour volumes of more than
300 vehicles
per hour for a duration of 3 to 5 hours
on weekends.
there was no record of the
Although
traffic flow when these traffic counts took place
the observation
indicates that the flow would
be bumper-to-bumper
traffic and that both
ditches
of the roadway would be used to accommodate
two-way traffic.
Figure 7 surprisingly reveals that
a single-lane
road can handle more than 400 vehicles
prob-ably
per hour.
It is important to be cautious
in interpreting
these
traffic patterns for use in choosing road designs.
Since the traffic flow was unknown
the results of
this analysis do not suggest that 400 vehicles per
hour is a desired hourly volume for single-lane
roads.
However this study does strongly indicate
that peak-hour
volume may be a better road design
criterion than daily volume.
For example at site
number 118 shown in figure
the daily volume
for
Sunday September 2 1984 was 2972 vehicles.
Based on a 10-hour day the average
hourly volume
was about 300 vehicles
But in fact the
per hour.
peak-hour volume exceeded 400 vehicles per hour.
For site number 007 shown in figure 8 the daily
volume for Saturday August 4 1984 was 1925
vehicles.
Calculated from this the average
hourly
volume would be nearly 200 vehicles per hour but
the peak-hour
volume actually reached
350 vehicles
hour.
Peak-hour
volumes
exceeded
daily volume
per
design for single-lane roads.
7
SUMMARY $
CONCLUSIONS
This study has analyzed variations in traffic
volumes with time based on data collected
in the
Mount St. Helens National
Volcanic Monument
area in
1982 and 1984.
Fifteen study sites provided
on traffic patterns on an hourly daily and
infor-mation
51
400
Recreational
Traffic
97%
traffic
vehicles
Daily
_-_Mon
---Tue
...........
350
Wed
T h u
-Fri
Sat
Sun
N
8/27/84
8/28/84
8/29/84
8/30/84
8/31/84
9/1/84
9/2/84
619
961
1184
913
690
1470
2872
300
GJ
r
U
s
250
aý
ai
r
200
O
150
100
50
\
-100
0
4
6
8
10
12
14
16
18
20
22
Hours
variations on site number
Figure 6.--Hourly traffic volume
August 30 through
National Forest
September 5 1984.
52
267
of Road
25
in
Gifford
Pinchot
24
400
99%_
vehicles
Traffic
Recreational
Daily
350
traffic
8
4
1107-----Fri
8/3/84
1030---Sat
T h u
/ 2 /8
8/4/84
8/5/84
-----Mon 8/6/84
-----Tue 8/7/84
Sun
300
.........
Wed
8/8/84
1925
N If
1714
1090
1400
1229
250
r
200
1
0
150
10 0
.
Mill
I
50
0
2
4
6
8
10
12
14
18
16
20
22
24
Hours
volume variations
on site number
Figure 7.--Hourly traffic
National Forest August 27 through September 2 1984.
53
118
of
Road
99
in
Gifford
Pinchot
400
-
Recreational
Traffic
95%
Daily traffic vehicles
350
T
h u
Fri
--Sat
Sun
300-------Mon
--Tue
..........
Wed
8/30/84
432
369
668
1401
1063
369
232
8/31/84
9/1/84
9/2/84
9/3/84
9/4/84
9/5/84
250-200-E
O
150-100-50-If
0
4
2
6
10
8
12
14
16
18
20
22
Hours
Figure 8.--Hourly traffic
National Forest August
volume
2
through
variations
8
on
site
1984.
54
number
007
of Road
99
in
Gifford Pinchot
24
These sites covered
monthly or seasonal basis.
a
whole spectrum of Forest road systems including
Road
arterials collectors and local roads.
from
double-lane
roads and
segments ranged
single- to
from native to paved surfacing.
The observed traffic
included traffic generated by logging and
activities.
recrea-tional
The
1
2
3
4
5
6
7
specific
findings
High log-hauling
September.
of
this study
traffic
are as
occurred
follows
in August
and
From largest to smallest the order of seasonal
traffic volume variations on road types was
arterials collectors and local roads the
order based on day of week was local roads
and arterials.
collectors
collec-tors
There
was more demand for arterials and
on weekends
than on weekdays.
On the
other hand local roads not open to the public
for recreational
travel were underused
on
weekends.
traffic had both morning and
Logging-related
midday peak-hour periods while recreational
traffic had only midday peak-hour periods.
The
from 4 a.m.
morning traffic peak hours occurred
to 6 a.m. and was about half of the
volume of
the midday peak-hour
period.
Midday peak hours
occurred from 10 a.m. to 5 p.m.
For single-lane roads during bumper-to-bumper
travel conditions in which both ditches of
roadway are used as road surface recreational
traffic may exceed 300 vehicles per hour.
cri-terion
volume may be a better road design
than daily volume because there is a
difference between peak-hour
and
significant
nonpeak-hour
traffic which is not reflected in
To do
averages based on daily volume rates.
so however hourly volume for a particular
duration needs to be defined.
Hourly
For
traffic controlled by CB radios when a road
not open to public
the ADT
of single-lane
roads reached
250
vehicles per day with the
majority of traffic consisting of logging
trucks.
is
55
be noted that this traffic volume study
on data from the Mount St. Helens Monument
area and therefore any interpretation of traffic
patterns beyond the controlled base condition would
of local data samples.
require verification
It
was
should
based
56
Evaluation of Computer-Aided Drafting
Design for Architectural
Structural
Engineering
George J. Lippert
Chief Facilities Engineer
Washington
Office
This is the first of several articles on the subject
of computer-aided
drafting and design systems.
articles will be provided for general
Subsequent
interest to field personnel as additional information
becomes available.
For this series of articles micro- and minisystems
are differentiated
by both size and cost.
Usually
have
less
than 1.5 megabyte internal
microsystems
memory and cost less than $40000 installed while
minisystems have greater than 1.5 megabyte internal
memory and a price range between $75000 and
$200000.
Both. are stand-alone hardware/software
to a specific application.
systems dedicated
And
because of internal memory size the capabilities
of
the
two are usually different.
In addition
two acronyms--CAD
and
CADD--are used in
these articles.
These and additional acronyms are
in the article
discussed
Review of Micro- and
Mini-CADD Systems.
These acronyms are used
CADD means both drafting and design are
included in the system.
CAD normally refers to
in
which
systems
only drafting is included.
A
inter-changeably.
computer-aided
The
Office Engineering Staff is
Washington
a
of
coordinating
four-part evaluation
and
drafting
design CADD systems and their
cost-effective
use in Forest Service
potential
architectural and structural engineering design.
there are some exceptions most structural
Although
engineering and architectural design is done at the
Offices.
Our evaluation
focuses on what
Regional
of
hardware
and
software
might be
configurations
shared or coordinated between the architecture
and
structural engineering disciplines both within the
Region and inter-Regionally.
Service-wide
poten-57
We have no doubt that automated drafting and design
will be cost effective.
The purpose of the
evaluation
is to investigate
and optimize
capabil-ities
At present
savings and other benefits of CADs.
wide assortment of commercial CAD systems
and costs are available.
The competitiveness
of the CADD market is improving users opportunities
level of needs
monthly.
However the appropriate
identified
and
investments
must
be
capabilities
before implementing major changes in work practices.
Installation and use of uniform CAD systems will
enhance the shape and transfer of detailed
and project data in usable form among
The opportunity also exists for
Regions.
design and review teams.
tial
a
tech-nology
inter-Regional
con-tracting
current funding levels are limited and
for work is being emphasized a concerted
effort is being made to identify the magnitude of
facility needs and recommend more realistic program
for design work is not cost
levels.
Contracting
effective
for small projects.
The advent of CAD
and reduce
increase
Staff
could
productivity
systems
overall cost considerably.
Although
under-taken.
During fiscal years 1984 and 1985 the following
four separate but complementary efforts were
MAINFRAME TIMESHARE SYSTEMS
COMPLETED
A time-share contract
that ran from May through
with
the
Control Data Corporation
1984
September
revealed that most large mainframe programs are
complex enough to require an indepth training
of systems far in excess of
program and knowledge
Forest Service design needs.
Telecommunication
were
user
support was
encountered
problems
and quality transmission was unreliable.
inade-quate
The
general conclusion was that mainframe time-share
systems are less feasible than available stand-alone
systems for the Forest Service.
Articles that further analyze this evaluation
appear
in this issue of Engineering Field Notes--see
Computer-Aided Design and Final Evaluation
Internal Application and Evaluation
of
Report
Control Data Corporations CD2000 Computer-Aided
Design/Drafting
System.
DESIGN WORKLOAD/
SYSTEM NEEDS
ANALYSIS
This effort is being conducted
by an A/E contractor.
Lee Wan and Associates
Incorporated a suburban
Atlanta design firm has compiled data received from
all Regions
has reviewed various micro- and
CADD systems and has provided its final report.
A copy has been sent to each Region and Station for
mini-COMPLETE-5/1/85
95-PERCENT
58
A future Engineering Field Notes
information.
article will discuss the findings.
Some discussion
from the report is included in the article
Review
of Micro
and Mini CAD Systems included in this
A
issue.
MICROCOMPUTERLEVEL CADD
SYSTEM UNDERWAY
Three IBM-PC hardware/PCAD
software systems were
installed in Region
8
in November
1984.
These are
First production
currently being evaluated.
project
level drawings were completed in January.
projects are under way to test the system in a
real world environment.
MINICOMPUTERLEVEL CADD
SYSTEMS
We
PENDING
Addition-al
proposed to install a two-station
CADD system in Region 5 for Service-wide
This effort now has been designed to
practicality and costs of manual
drafting systems in a
design with automated
micro-environment.
The rationale for this change is
discussed
in the
article
Review of Micro- and
Mini-CAD Systems.
orginally
minicomputer
evaluation.
evaluate the
inte-gration
A
the
evaluations
of micro- and mini-CAD
were
to
be
separate but parallel generic
systems
efforts.
Two complete CAD workstations with
supporting peripheral equipment were proposed for
each test Region.
These Regions would have two to
in producing
three trained designers proficient
These hands-on efforts would give
design drawings.
the designers
sufficient knowledge
to compare other
While
hardware/software
systems
quality
systems.
were to be installed the evaluation
was not
to test the
selected system but to permit a
of
it
with
other systems within the same
comparison
level
of
a
CAD
generic
system.
Originally
in-tended
the minisystem evaluation
has been modified
Although
will be
the results of the microsystem
evaluations
for
in
use
acquisition.
Inter-Regional
merged
committees are planned for
writing performance
and evaluation
criteria for
specifications
and
developing
system guidelines to ensure
the
of
and
textual data bases and
sharing
graphic
an in-Service
project drawings that is developing
user group.
1
acquisi-tion
2
59
Computer-Aided Design
Bob Swarthout
Civil Engineer
Fong L. Ou
Engineer Systems
Office
Washington
Analysis
Development
analy-sis
of a
This article describes the application
design system provided by Control
computer-aided
Data Coporation CDC to develop a structural
three-dimensional
of a complicated
structure.
A
three-dimensional
analysis provides designers with a
better understanding
of the interrelationship
of
stresses and strains between members within a
than is possible with a two-dimensional
Based on such an analysis the designer will
be able to select the most efficient
members and
connections
for the
structure
with
complete
of overall safety factors.
This
article has
been prepared for publication
in Engineering Field
Notes to increase awareness
of the potential
of the
latest technology
for improving structural analysis.
The CDC system is available
through a time-sharing
contract.
struc-ture
analy-sis.
consid-eration
INTRODUCTION
is becoming
Computer-aided
design CAD increasingly
tool
for
structural
in
designing
a major
engineers
The benefits of using a CAD
engineering structures.
greater
system include increased productivity
saved in
in
time
efficiency
making changes
and
reductions
in
project development
redesign work
accu-racy
time.
Forest Service designs and builds 150 to
bridges and about 100 buildings every year.
Nearly 40 personnel are assigned to carry out this
The size of the task suggests that a CAD
work.
system could greatly improve the efficiency of these
In light of
in structural
analysis.
professionals
Office sponsored the
this potential the Washington
use of CDCs CAD software for a trial period.
The
300
tech-nology
The main purpose of this trial period was to gain
hands-on experience
with the computer graphics
and
its ability to reduce time and costs
61
Office
for Forest Service designers.
The Washington
Technical
and
Analysis
System
Application
Engineer
and
in this application
Engineers participated
evaluated
the potential use of a CAD system for
structural analysis.
CDC CADD
SYSTEM
The
CDC provided a Computer-Aided Design and Drafting
CADD System including CD2000 UNISTRUC and
GTSTRUDL
CD2000 is an automated
design
programs.
basic
and drafting programming system.
It provides
such
as
a
line
point
geometric definitions
circle and arc for use in creating designs of
three-dimensional
UNISTRUC is an
parts.
and
graphics preprocessor
postprocessor
that automatically
prepares the input for the
finite element routines in GTSTRUDL
from the
of the structure
on
the
CRT screen.
developed
results
of the
It also automatically
the
interprets
The
CD2000
from
GTSTRUDL
for
CRT
viewing.
analysis
also can be used to generate
the
structural model.
This input is used by GTSTRUDL
for the structural
finite
GTSTRUDL
is a general purpose
analysis.
element structural analysis program that has been
from the original Massachusetts
Institute of
adapted
ICES/STRUDL
Technology
by the Georgia Institute of
The output shows the stresses and the
Technology.
strains on each member and the moments at all
connections.
two-and
inter-active
pro-gram
draw-ings
APPLICATION
illustrate this design and finite element
analysis application a two-story structure with a
first floor of 50 feet by 40 feet and a second floor
of 24 feet by 20 feet was chosen.
In this example
all of the floor truss roof truss and walls were
combined into a single rigid-frame structure model
for analysis.
This is a very large finite element
model and does require a large computer for analysis
in a reasonable
period of time.
To
center-line
The analysis is begun by showing
Drafting by CD2000.
the
structure with lines that represent the
of
each member.
This drafting started with the
selection of the origin point of the drawing.
Based
on the origin four corner points of a basic panel
of floor truss were created
as shown in figure 1a.
four
lines
four pairs
drawn
were
Then
by connecting
of points
as shown
in figure 1b.
Through entity
and
was duplicated
manipulation figure
nine times as shown in figure 1c.
once and rotating it 180 degrees
figure
resulted in figure 1d.
trans-lated
Dupli-cating
1b
1c
62
b
a
r
c
d
Figure 1.--Process for
creating a floor truss.
The
roof truss was developed
by locating five points
member
at
intersections
and
these points
connecting
with lines as shown in figure 2a.
The design of
the roof truss for the first floor shown
in figure
was completed by duplicating
once
figure
2b
and
rotating
it
180
2a
degrees.
2b
shown in figure 3 figure
and
was duplicated
translated five times in each case 2 inches apart.
and
Figure 3 was duplicated
translated once thus
completing the design for the portions with one
level.
Figure 4 illustrates the truss for one level.
As
2b
truss figure
for the one-floor structure
was modified for the portion of the model with two
stories.
The
Figure 5 shows the modified truss.
design of the two-story portion was completed by
duplicating
figure 5 and translating it thirteen
times as figures 6 and 7 show.
Figure 8 displays
the portion
of truss above the floor.
Figure 8 also
shows a 72-inch by 82-inch door and two 72-inch by
50-inch windows.
These are included to demonstrate
the advantage
of a three-dimensional
analysis in
analyzing the effects of removing parts of several
truss frames.
Figure 9 shows both front and right
views of the structure with their dimensions.
The
63
b
Figure 2.--Truss for
one-floor section.
roll%
214.-Figure
3.--Truss for
one-floor section.
64
r
r
x
x
Figure 4.--Two
ends
of structure
with
one
floor.
V
t
x
x
Figure
5.--Truss for
two-floor section.
65
A
-410
L
Figure 6.--Floor truss
for
two-story section.
f
x
x
L
Figure
7.--Portion
of
structure
with
two
stories.
66
100
00
ro
a
Figure 8.--Structure
truss
above
the
floor.
T_
os..o
9.
2ým
0....
..00.
Front View
Right-Side View
Scale
Figure 9.--Front and
right-side views.
67
1
100
a Finite Element Model With UNISTRUC.
Generating
the
Using
geometric data from the previous step a
finite element model was generated with UNISTRUC.
The model is shown in figure 10.
Figure 11 displays
a zoomed portion
of the truss with node numbers.
analy-sis.
element model a section of which appears
for
figure 12 was submitted to GTSTRUDL
The results of this analysis are discussed
in
the
section.
following
The
finite
in
applica-tion
Structural
Analysis by GTSTRUDL.
entire three-dimensional
element model was included
the
finite
In
this
space
frame
structural
in the
and
Z
well
moments
as
as
forces
analysis.
about the
and Z axes were developed
at each
node point.
A GTSTRUDL
run was made based on the
that the combination
of live and dead
assumptions
loads is 25 pounds per square foot the module of
elasticity equals 0.12 x 107 pounds per square
inch for wood framing materials and the size of
member ranges from 2 inches by 4 inches to 2 inches
by
6
X Y
X Y
inches.
Z
JIx
Figure 10.--Finite
element model of the
building.
68
t
ýe
T
Figure ll.--Zoomed
portion of finite
element model.
2
s
x
12N
1lM
1/79
129/
19
72
I
M
Si
7W
3
3/2
12M
19/
9//
1192
M
N/9
291
R2
72
/
1
/79
79
73
12
12
SS
2
1
1
1
11
121
7
t
Figure
finite
12.--Section
of
element model.
21
121
1
2
69
K
summa-rized
The first part of the output contains the input
information.
The second part of the output presents
the
analysis results a portion of which are
in four tables.
Table 1 shows the member
and in moment z.
Table
forces in axial and shear
2
in both x and y
depicts the joint displacements
coordinates
and
the rotation of the
z
coordinate.
Table 3 presents the joint loads for supports.
Finally Table 4 shows the member stress in terms of
y
maxi-mum
z bending
axial y shear z shear y bending
The members with
normal and minimum normal.
incorrect or
were denoted
insufficient properties
errors.
by STRUDL
for stresses
system is capable of drawing various
For simplicity
aspects of a structure.
is illustrated in
only a portion of roof overhangs
this article.
roof
Figure 13 shows a two-dimensional
overhang while Figure 14 shows a three-dimensional
display of the same overhang.
Details.
detailed
LEARNING
CURVES
A CADD
suffi-cient
The Washington
Office evaluation
period took less
than 3 weeks.
This is too short a time period to
understand
fully this complex system without
However based on
support from the vendor.
this experience
it seems that a user could
acquire
considerable
proficiency
quickly if sufficient
support from the vendor is available if the hardware
if the
is satisfactory and
system is used
For example with no assistance from CDC it
took 5 days to learn how to create the truss in
After learning the procedure it took
figure 8.
only 30 minutes to develop the same truss the second
time.
For creating a three-dimensional
roof
second
the first trial took 2 days but the
took only 1 hour.
continu-ously.
over-hang
After finally obtaining adequate
support the
drafting shown in figures 3 through 12 was completed
in 3 hours with the
immediate assistance of a CDC
to a finite element
specialist and the conversion
model was almost instantaneous.
CONCLUSIONS
of CDCs CAD
This paper has shown the application
system to a structurally complicated
space frame
structural analysis using finite elements for a
The experiment
hypothetical
two-story building.
indicates that considerable
savings could be
achieved using CAD as a structural analysis tool.
An experienced
user could do the work shown here in
in its accuracy.
a few hours with high confidence
The savings in structural
analysis costs would be
70
Table
1.--Member
RESULTS
OF
forces.
ANLLVSES
LATEST
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___...........................
.
-.43L93211
..........
-.0010005
......__.0192
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_..0000957
0
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00431....-_.
6
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-.0166479
2602770
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L .................260277
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.0003000.___._.
.002020
.001095
-3.4002771
0.0000000
------------------------1002771-------W.4006004
__...._
0
..___________________________________________________.-000000
00109 S 7---------.0000000
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LIVE3
...........................
______-____________________-_______________________.
-___
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NONE MT
1.00o00
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0000000-._...-f
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TORSION
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-...............................................................
---_-.__...__-________________-_________________10000000________
-7.776675-__.___...__0.41106_..__-3.716675
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LIVE
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0.0000000
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005774r-__
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1047276
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0.0000000
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1.000
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0.0000000
FR
4_.000
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4.W6YJZr
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1-46SY2BY------1.4912461
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DEAD
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------------._--.-_-.--_---_ ------- ---------------------
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EVADING
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M._.__-_________________________________________--------.----___---__----.---____________.-____._.__-.-.--_-__
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.._________________________________________________.._--_.____________..-.-_.
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LOADS
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supports.
ACTIVE
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3.--Joint
loads
Table
over-hangs
Figure 13.--Roof
in two dimensions.
0
0
0 0
0
0
0
Figure 14.--Roof
overhangs
in
three
dimensions.
appreciable
compared to the costs of an analysis by
It
should be noted however
that
any other method.
a
sophisticated CAD structural analysis may not be
justifiable for building structures using light
inches by 4 inches
2
inches by 6 inches
framing
and
so forth because the
savings in construction
costs resulting from increased knowledge
of actual
stresses and strains will not save sufficient
to compensate
for the additional structural
cost.
analysis
Instead this type of analysis would
be useful for reducing the cost of bridges
and
towers.
2
mate-rial
Direct questions regarding this paper to
C.
Swarthout or Fong Ou at FTS 235-2376/235-3119
703 235-2376/703 235-3119.
73
or
Final Evaluation
Application
Report-Internal
Evaluation of Control
Computer-Aided
System
Data Corporations
CD2000
Design/Drafting
Frank Muchmore
Structural Engineer
Robert LeCain
Architect
Region 1
following
report presents Region ls evaluation
the Washington
Offices contract with Control
Data Corporation CDC in fiscal year 1984 for
time-share service with CDCs computer-aided
design/
The purpose of the contract
was to
drafting system.
allow the Forest Service to evaluate the CADD system.
Robert LeCain and Frank Muchmore from Region 1
Nelson Hernandez
from Region S and Dick Smith and
Bill Grabner from Region
6
attended a 1-week training
session in Rockville
from May 7 to May
Maryland
The
of
11
1984.
While attending
the training we realized that a
digitizer tablet would be absolutely necessary for
efficient use of the CD2000 system.
Tablets were
not contemplated
in the original plan so the
was delayed while they were being procured
Office.
CDC did loan a tablet to
by the Washington
Region
1 which was installed on July 9. The tablet
Office was delivered and
by the Washington
purchased
became operational on August 7 after which the CDC
tablet was returned to the Washington
Office.
imple-mentation
1 evaluated
the
Region
June through September
EVALUATION
CRITERIA
CADD
1984.
system during
the
months
The Plan for Internal Application
and Evaluation
of
Computer-Aided Drafting/Design
System outlines the
criteria used for this evaluation.
Each item is
analyzed below.
1
Ease of data entry and modification.
Very
difficult at first.
CD2000 is very complex
because of its versatility and multiple
for use.
Many proper responses must
be made to enter data or to change previously
entered data.
Obviously as with any learning
possi-bilities
75
learned
once a function is thoroughly
longer seems difficult or complicated
however
retaining that learning efficiency
requires constant use which does not seem
likely with this program.
process
it no
2
3
4
connec-tion
The
reliability of the system for phone
to the vendors computer system.
Very
poor
Rarely did it function 100 percent.
Problems varied from occasional blips
unwanted characters or lines to complete loss
of work in progress.
applica-tions.
Internal application
and
results are accurate
We have made no internal
complete.
Because of the problems of data entry
and system reliability as well as other
problems we did not.seriously attempt any
work.
production
However CD2000 certainly
allows accurate
and complete results provided
data are entered completely and accurately.
Operating
functions
a
costs
are
reasonable
for the following
Training
Training materials are sufficient to both
this was
quality and quantity--Generally
true.
Adequacy of the CD2000 users manual
varied greatly.
Some areas were logical
and understandable
and some were not.
b
c
d
of troubleshooting
assistance
Availability
after initial training is completed--CDC
was cooperative
and tried to be herpful.
However because of the large size and
it
specialization in their organization
was sometimes difficult and time consuming
to get to the proper person for assistance.
appro-priate
appro-priate
appro-priate
Data
collection--This
item was more
to the structural
analysis programs
which Region 1 did not evaluate.
Data
item was more
preparation--This
to the structural
analysis programs
which Region
1 did not
evaluate.
Data
analysis--This item was more
to the
structural analysis programs
which Region 1 did not evaluate.
76
e
f
5
with
the
performance
of
the
system.
b
7
Communications--The
phone link to the
computer ranged from quite good to
terrible.
At worst the system was totally
unusable with so much garbage appearing
on the screen that communication with the
Time-share does not
system was impossible.
seem to be the way to handle a production
situation.
Users satisfaction
a
6
log-on process was
Computer process--The
cumbersome and seemed to be a carryover
from the old punch-card
The process
days.
definitely was not user friendly.
comments--I was intrigued by
versatility and complexity of the
However this same versatility
system.
A
made it difficult to learn and use.
program that does much less but that is
user friendly would be much more
to our needs.
Architects
the
appro-priate
Structural Engineers comments--This
CD2000
is extremely powerful
and
system
flexible which makes it necessarily very
For the type of applications
we
complex.
Probably 80
have it is far too complex.
to 90 percent
of the
systems capabilities
A
are not needed at all for our drafting.
much simpler and more user-friendly system
would be far more useful to us.
Functions of the system that may be performed
in a cost-effective
For standard
manner.
drawings a CADD system would be quite useful.
manual
For any one-time-only drawing however
methods would be faster.
The computer obviously
can change scales and so forth very easily
that
is relatively
however
unimportant in
of architectural
a set
or structural
developing
drawings.
System-generated
reports are readable and
Not applicable to
by users.
easily understood
t
e drafting
functions which is all that we
tested.
77
8
9
10
GENERAL
COMMENTS
Reasonable
protection from data loss.
to be but only if one performe
pack
file often.
Line disturbances
or the
link which caused garbage to appear
screen increased data loss.
Seemed
and
phone
on the
data errors or difficulties
System-identified
are easily located.
This depended on t e
function
It varied
from
drafting
being used.
the obvious
to the
impossible.
Calculations and analytical procedures
are an
Yes
integral component of the system.
But.of
little or no importance
for drafting functions
which was our primary area of interest for this
evaluation.
The speed of screen repainting was very slow on the
Techtronix
4014 terminal.
As the drawing becomes
more complex repainting time becomes significant.
This interrelates
with the following
1
2
3
Menus
covered
the drawing
rapidly which
required frequent
repainting of the drawing.
Menus on a separate screen would seem to be
significant
advantage.
Some functions
such
a
dimensioning
required
zoom up to
pick up an entity zoom down to pick up another
area of drawing zoom up to pick up the next
This zooming required a
entity and so forth.
deal
of
great
repainting which was cumbersome.
A scroll feature that allows moving back and
forth and up and down without
changing scale
would be useful.
the
center
of the
Moving
screen did this to a very limited degree but
required screen repainting at each move.
a
lot
of
zooming
as
for instance
T
in midpaint
Cancelling
repainting Control
because of entry error or other problems often
resulted in loss of an entire program CD2000
which of course required starting over and
resulted in loss of work that was in process.
The
When
ergonomics of the terminal were very bad.
the digitizing tablet
there was no good place
to put the
tablet.
The keyboard should be separate
from the screen display like FLIPS so that the
keyboard and tablet can be arranged in a comfortable
manner.
Also it was time consuming having to gather
your users manual and other materials and go from
using.
78
At
third floor to the basement where
All of these are Forest
located.
problems not CDC problems.
the
was
the
terminal
Service
difficult to enter points lines and so
There was no practical rough
forth close enough.
scale.
There was a grid but repainting the screen
with the grid turned on was unacceptably
slow.
It
was
Shading
choices were very limited and difficult
Even very simple software architectural
for
personal computers have many more
programs
shading choices.
to
control.
Automatic
functions
dimensioning and entry of dimensions
were only in inches or metric in other
words no measurements were in feet and inches.
for architectural or structural
This is impractical
work.
Plotters in Region 1 were not comptabile with CD2000
have
for direct link.
To obtain a plot it would
been necessary
to have CDC make the plot and mail it
This would
1.
or make a tape and send it to Region
work.
be completely
for production
unacceptable
control
to
allow
CD2000
to
Although
equipment
available such
Region 1 plotters is undoubtedly
otherwise
be
or
might
quite
costly
equipment
difficult to obtain.
on CD2000
Training time needed to become proficient
for our purposes.
Because of
seems to be excessive
the
complexity of the system there is no easy way
For example Rockwell
to become trained in its use.
International as reported in Design Graphics World
uses CD2000 and the CDC design
July 1984 page
and analysis programs in their space shuttle
They require each engineer to be trained for
10 weeks
in the basic applications
and do not certify
their people as qualified until after they log about
200 hours on the terminal.
They claim a 2-to-1
gain over conventional methods after that
time.
However until that skill level is attained
they find that the learner is still quite vulnerable
and may find snags make excuses
and go back to his
We cannot afford that much
or her old ways
training either in terms of time or money.
divi-sion.
17
pro-ductivity
RECOMMENDATIONS
CD2000
is
not
the
CADD
system that we
need.
kinds of work we do we see less need or
design system than
potential for a computer-aided
For
the
79
for
a computer-aided
drafting system that will
and revision to working drawings.
preparation
allow
Because
drafting is only a part-time function with
system must be easy to learn and use and
relatively inexpensive both in terms of
initial cost and use cost.
us
the
must be
To maintain state-of-the-art
capability the primary
hardware must be of a general purpose type that
allows software to be updated.
single-purpose
The
of
for
the
equipment
people
the
use
not
be
using
If
use.
it will
learning
the
located
and be
machine
must be
phase.
it
used
within
work
the
area
primarily
not readily available
particularly during
a
is
A paper germane to the subject was presented
by
E.
Bowles
October
the
American
on
at
Joseph
4 1984
Society of Civil Engineers Convention in San
Francisco.
Bowles discussed
the micro- and
and
the
additional
systems
power and
usability of these new units.
mini-computer
80
A Review
of Micro-
Systems
Mini-CADD
George J. Lippert
Chief Facilities Engineer
Office
Washington
eval-uations
Authors Note
the
Although
original CAD evaluation
plan proposed both mini- and microlevel
it became increasingly
that the
apparent
in
would
have to
differences
costs and capabilities
A
review
be justified to conduct
both evaluations.
led
cancel
was made that
to the recommendation
to
the minilevel evaluation
and to add a second
evaluation.
The review provided an excellent
make
a
side-by-side comparison of
opportunity to
several systems and to discover some aspects of CAD
The following
systems vital to potential users.
report was made and submitted to the Directors of
and
the Engineering Staff and Computer Science
Staff in June 1985.
action
micro-CADD
Tele-communications
EXECUTIVE
SUMMARY
The past 12 to 15 months have been devoted
to
studying CADD systems their capabilities and
The
potential benefits to the Forest Service.
majority of this effort has been to review the
potential of micro- and minilevel stand-alone CADD
A micro-CAD
and
systems.
system has been purchased
is undergoing
evaluation
in Region
8.
evalu-ation
to form some
Enough information has been gathered
conclusions with regard to present day mini-CADD
systems and to recommend revising near-term
actions.
there are major capability differences between
present day micro- and minilevel CADD systems it is
becoming increasingly
apparent that for
and structural engineering design in the Forest
Service the microlevel CADD systems offer sufficient
than the
and are more cost effective
capabilities
more expensive more highly integrated minicomputer
CADD systems.
The micro-CADD system market is very
with
better
dynamic
products being offered every
few months.
This situation will continue for some
time and the present differences in capabilities
between micro- and minisystems may soon be history.
While
architec-tural
81
RECOMMENDATIONS
1
2
sys-tems
The
hands-on evaluation
of minilevel CADD
should be held in abeyance until further
notice.
Efforts should continue to stay abreast
of CADD market development
in the minilevel
field.
sys-tem
Acquire additional but separate micro-CADD
software for further evaluation.
Use IBM-AT
hardware.
test to use
Expand the evaluation
IBM-compatible
engineering
design software and
evaluate the practicality
of manual integration
of computer-aided
drafting and design.
3 implemen-tation
4
DISCUSSION
Consider minisystems only after the
of CADD and the demonstration
of a need
for more than five workstations
office.
per
Require the use of Initial Graphics Exchange
IGES formatted software to
Specification
allow projects to be shared between Regions.
Evaluate
and determine system requirements and
features on a must have versus want basis for
the
of CADD systems in fiscal year
acquisition
1986 and beyond.
Staff
During the past 12 to 15 months considerable
effort has been devoted
to becoming more familiar
with CADD systems and to develop an indepth
of the capabilities
of both CADD hardware
and software and their applicability to architectural
and structural engineering disciplines.
under-standing
Concurrent
with these efforts Region 8 has begun
its evaluation
and production
drawings using a
micro-CADD system and the contractor Lee Wan and
Associates Incorporated has been working on its
review of micro- and mini-CADD systems.
Much of our
time has been spent in viewing demonstrations
pricing systems and discussing CADD systems
with several individuals both inside and outside of
the agency.
The following
is a digest of our
from a host of sources.
read-ing
Whats in an
Acronym
find-ings
With many buzz
say CADD
in new meanings
read
change people
and
so forth.
CADD is no different.
CADD
and
CAD
drafting
design
computer-aided
drafting or computer-aided
design CAD/CAM
computer-aided
manufacturing CAE
CAEAD
engineering
computer-aided engineering
and architectural
design CAE/CAM computer-aided
engineering and manufacturing CASD/M
What
do
we
mean when we
computer-aided
computer-aided
words meanings
computer-82
aided
space design and management
computer-integrated manufacturing
CIM
have a common
been using
and
We have
thread--computer-assisted.
computer systems for 25 years so--whats
pre-sented
new
the
attribute common
the use of graphic
to the acronyms
displays and interactive
Without
a doubt
graphics are desirable
graphics.
for solving many types of problems.
For
and
structural design
graphics is a language
for communications.
Designs are usually a graphical
Can graphics or
depiction of a desired product.
The
computer aids be used all the time for design
a software
answer is
Holguin Associates
firm estimates that considering the level of
graphics used in problem solving while almost 100
can be automated
percent of drafting activities
activities and
only abut 60 percent of architectural
activities can be
30 percent of engineering
automated.
Perhaps
is
architec-tural
no
What
$
It
Isnt
Is
These names are frequently used
CAD/CADD.
interchangeably.
Expressed separately the first
second
is design.
in CADD is drafting the
This is an important distinction.
D
D
mega-bytes
generic computer hardware
usually has less than 1.5
but increasing daily internal memory and
The latter has a larger
costs less than $40000.
internal memory and costs considerably more.
As
the
expected
larger the capacity the larger the
price.
Micro/Mini.
The
terms.
These
former
are
Hardware/Software.
While magazine articles and
numerous advertisements tout the attributes of one
care is needed when
system or another considerable
Some softwares are little
investigating
systems.
more than electronic
pencils ranging in price from
Others vary by their degree of
$500 to $50000.
integration.
Integration
might be best explained by
In a highly integrated architectural
an example.
CADD system a number of operations occur with the
recall of a standard detail from the data base.
are outlined quantities are counted
Specifications
finish schedules are developed
and when the detail
all views and
sections
is placed
with the design
are correctly oriented and labeled.
the comparatively
higher price of minis
over micros can be attributed to the degree of
the
integration of both drafting and design
Generally
83
required size of data base and the
needed.
Thus with micros you get
CADD.
can
get
you
internal
memory
CAD with minis
Roots
in the sense of what the software was
We recently
developed
for are extremely important.
attended a demonstration of GRAFTEX software.
This
is a very powerful
three-dimensional
drafting program
capable of both wire-frame and solids modeling in
more than 300 colors.
The program was written by
and for mechanical engineers for tool and die design.
While technically
adaptable the program as written
is not practical
for producing
architectural working
documents.
The best
drawings and other contract
softwares are those written by and for applications
within a given discipline.
Software
selection must
be on that basis as well.
Driving Forces/
Costs-Benefits
Soft-ware
capabili-ties
When considering
a CAD/CADD
system the dominant
issue is software capability.
Hardware
is normally
selected to operate the software efficiently.
programs will have various degrees of
and will integrate data base systems.
Heavily
integrated drafting and design programs usually
minilevel computers.
However several highly
integrated drafting programs are available in the
microcomputer
market.
re-quire
The differences in cost between an integrated CAD
system
good drafting program with a high level of
geometric data storage and integration
and CADD
fully integrated drafting and
is about $75000 to $150000.
design program
firms advertise micro- and mini-CAD systems for
under $15000 and $50000 respectively.
These
do
all
the
hardware
and
include
not
prices normally
software necessary for production of construction
documents.
For instance multipen drum plotters
from
These are priced
$7500
to $20000 each.
range
Once
an
office
has
common
separately.
support
and software the
costs of the next CAD
are closer to the advertised prices.
Sev-eral
a
capabili-ties
a
hard-ware
work-station
one would expect an increase in benefits
Although
with a more fully integrated program this is not
necessarily the case.
Many features cannot be fully
used.
Minilevel
design programs often include far
Because of
more design capability than is needed.
their integration and their being generally more
completethat is structural engineering from
simple beam analysis to finite element analysis
minilevel design programs may cost 8 to 10 times as
84
much
as microlevel systems.
The micro-CAD market
several excellent integrated drafting programs
which while lacking some features such as three
dimensions modeling and so forth are sufficient
The item missing in
for most Forest Service work.
micro-CAD
is
the
most
systems
ability to directly
integrate design structural analysis HVAC
electrical circuit analysis hydraulics into the
drafted project.
In both micro- and minilevel
programs good drafting and design programs exist.
has
bene-fits
Rela-tively
Finally
opportunity to capture potential
of use.
directly related to frequency
is
all
that
is necessary
noncomplex
analysis
with most Forest Service facilities.
Lee Wan and
that most
Associates Incorporated has concluded
the
Forest
Service
can
design analysis required by
be accomplished
small
individual
microlevel
using
Generally
programs with manual integration.
manual integration involves moving the drafted
project to a file loading a design program in the
computer and calling up sections of data from the
file for analysis.
Drafting is completed after the
is
While this is not
design analysis
completed.
the
consultant
has
automatic
suggested that we
be
unable
would probably
to fully amortize the
investment
larger
necessary for full drafting and
design integration.
the
is
Marketplace
Realities
the present software market is expanding
Although
vendors
most
target particular segments of the CADD
market. This targeting is associated with the
roots discussion earlier. GRAFTEX Corporation has
stated that its goal is to serve the largest segment
of the market.
to its market surveys
According
mechanical engineering
machine design is the
largest electronics and electrical design is second
the
and civil engineering
is third.
By comparison
is
5
6
times
civil engineering design market
to
All
smaller than mechanical engineering design.
other design fields including architecture were
less than one-tenth of the mechanical design market.
pro-grams
While
there are several firms writing software
for segments of the smaller design market the
scale of the market the popularity increasing
availability and use of microbased programs for
similar work is apparently causing major divisions
in marketing strategy.
Considerably more activity
is occurring
in the microbased than in the minibased
CADD industry.
firms are in effect
Microcomputer
their
leap-frogging
competition with newer better
85
accel-by
in-creased
and expanded capabilities with each new
introduced.
This situation is being
program
erated
the
introduction
of the super micros for
With larger internal memory
instance IBM-AT.
and other features at lower
computer speed
it
is
almost certain that the
comparative
prices
differences in integration of drafting and design
system capabilities and cost between present day
micros and minis will disappear in the next 5 years.
software
mini-of
FACTORS SHAPING
the
EVALUATION
the MINICOMPUTER CADD
SYSTEM for
REGION 5
with the original evaluation
proposal we
several
to
options
investigated
acquire a
S.
CADD system for use and evaluation
by Region
Because this is a generic evaluation
effort several
These
criteria were used to compare system options.
Consistent
were
1
Obtain
a
b
c
2
a
Cost-effective
Evaluation
of
Minilevel
CADD.
Because of the learning curve associated
with minis we determined
that this would
evaluation
of at least
an
period
require
1
could
be
Lost
year.
production
recouped
during
a
1-year
period.
Staff size was considered.
Sufficient
staff is needed to dedicate time to the
without
evaluation
seriously interrupting
production.
Because
keep costs reasonable.
of
a
system
fully
integrated
price
could be significant we were particularily
interested in what was available
to
before full commitment
evaluation.
Need
to
the
generi-cally
minicom-puter
Salvage.
a
b
consid-ered
point--leas
that minis would be
recognized
to
evaluate we
potentially
costly
breakeven
The
normal
leasing.
to purchase--was
15 to 18 months.
Vendors were not too interested in leasing.
In one instance leasing for 1 year would
cost about 11 percent more than the
purchase price.
Because
we
The most viable salvage option
consider Data General hardware
86
was
to
MV 4000
i
Lot
7
HP 9020 series for potential
reuse in other existing Forest Service
systems.
or
c
3
A third option was to consider only systems
with standard components.
Intergraph
Corporation has a very good CADD system.
However Intergraph significantly modifies
standard DEC/VAX
equipment so that only
Intergraph programs can be used.
sys-tems
Need
to evaluate both drafting and design
capabilities.
Originally only integrated
were considered.
After discussions
with
several vendors regarding capabilities
and cost
of both basic software
and
specific design
applications this criterion was modified.
It
that the second
appeared
in CADD would
be
extremely expensive.
D
arch-itectural
partici-pation
Criterion 1--evaluation of a mini-CADD--was
satisfied by assignment.
For both
and structural
engineering only
5
and 6 were considered
for the mini.
Regions
Region 5 expressed strong interest in
and was therefore selected.
easily
Criterion 2--salvage--was difficult to compare
but did limit the wide choice of equipment.
Choosing systems based on hardware rather than
software does violate a principal tenet of
system selection.
However because the
was generic rather than specific concerning
software matching acceptable
softwares for a
selected support hardware was considered
The concept of our generic evaluation
prudent.
was to use a good system and become proficient
enough to intelligently evaluate other systems
in the same general level through vendor/user
evalua-tion
discussions
forth.
reading
demonstrations
and
so
prac-tical
Criterion 3--evaluation of drafting and
designing--was
to the
extent
accomplished
with a side-by-side comparison.
The
results appear in table 1.
Because the features
of each system were somewhat different
this
analysis is an approximation.
CONCLUSIONS
While
there are some well-developed
commercial CADD
systems that provide integrated drafting and design
very little is available below $150000.
Vendors
87
Table
1.--Mini-CADD
evaluations.
ICM/
HP9000
9020a
Item
Holguin/
GRAFTEX/
or
Sys
Comp/DG
Intergraph
HP1000a
9050
HP9000
Hardware
Costs
1st Work
Stat.
109700
129000
57000
68000
68000
complete
2nd Work
Stat.
23000
48000
15000
23800
23800
20000
15200
30000
50000
3D
2D
3D
3D
16000
None
25000
25000
Software
Basic
Integrated
65000
Drafting Package
Added option
3D
Capability
Analysis
Design
20000
Unknown
Training
3 persons
Est.
Cost
User
Numbers
extra
22500
20000
6000
2600
217000
219000
89800
146800
Many
Unknown
Few
Many
est.
7
HP
3000
169800
Recent
Issue
good
Packard
recommended that should
drafting
representatives
should
both
be desired
both
hardwares
and softwares
analysis
systems
design
is
HP recommended a
be
The
estimated cost of one station
$197000.
purchased.
did not provide the
less expensive option the GRAFTEX/HP System.
This however
for the
type of integration capabilities
disciplines being considered.
allewlett
and
Sev-eral
Commentary
one of four
third-party
and offers
perhaps the
have
reviewed
Engineering Staffs
Limited users.
applications need updating.
Com /DG--Sys
Data
1
and 5
Regions
Sys
for
Not
is
Comp
hardware
architecturally
integrated.
architectural
good
Intergraphh--Very
esd ign
Good
applications.
update
Additional
work
stations
are very
Holguin/HP1000--Good
Good
available.
written
vendors
providing CADDs
best
software
of this group.
Sys Comps EASINET program.
Has
mechanical
engineering origin.
architectural
update
drafting
potential.
expensive.
drafting
program with some
Software modules
package.
No
related
are
structural
engineering
expensive.
design
analysis
potential.
manufac-turing.
ICM/HP9000--Poor
drafting
GRAFTEX/HP9000--Very
No
good
architectural
package.
drafting
Good
and
integration.
modeling/design
analysis.
design
programs for tool and die
for architectural
No
vendor
support
planned
users.
88
mini-level
i.
with programs compatible to hardware that could be
integrated with existing Forest Service hardware
offer very limited choices.
The lowest priced
system offered by Hewlett Packard
is the
combination.
The HP1000 will not
Holguin/HP1000
operate the road design graphics program currently
run on the Hewlett Packard Model 9020 Lot 7.
The
Sys Comp EASINET program is costly and has limited
architectural
integration capabilities.
sys-tems
Engi-neering
Lee Wan and Associates
Incorporated under contract
to evaluate needs and recommend
cost-efficient
has
indicated that the Forest Service should
focus on the expanding microcomputer
field.
can be run on the
design applications
same
but in a nonintegrated
In
the
process.
consultants opinion it would be diffcult to justify
and amortize the
investment of a fully integrated
drafting and design system over functionally
similar
but less sophisticated
micro-CAD systems.
hardware
Lee Wan and Associates viewed several microsystems
and evaluated
three of the more highly qualified
micro-CADD systems
AUTO-CAD PCAD and Versa CAD.
Of these three the consultant
recommended
that we
consider Versa CAD.
It based this determination
on
its analysis of the Regional
Office design workloads
types and complexity of designs and a comparison of
CAD features appropriate
for Forest Service design
automation.
In addition
Versa-CAD is written with
the Graphics
Exchange Specification
file structure.
This allows a computer to process data from another
computer almost directly.
Lee Wan and Associates
suggested that five workstations
per office would be
an approximate
cost breakeven
point for separate
micros in one office.
Above that number
a
minisystem with appropriate
software could be
considered.
The consultants recommendaton
for a
minisystem is the Holguin/HP1000
The
system.
softwares of both would enable inter-Regional
exchange of project files.
compati-ble
IGES-based
minicom-puter
Based on the findings of our review of the
CAD market with salvage potential and the
consultants recommendations I recommend that we
abandon the minicomputer
evaluation
in favor of the
While Region 8 is currently reviewing
microsystems.
a microsystem
PCAD/IBM-PC it is not conducting
I
recommend
design analysis.
expanding the
of micros using Versa CAD/IBM-AT
or a similar
evalu-ation
89
quality system and testing the practicality of using
an integrated drafting system and nonintegrated
engineering design.
The
IBM-PC/AT
or compatible hardware is readily
and a wide variety of third-party
and general application
software is
salvageable
A/E design
available.
90
Uý$
The Series
Engineering Technical
Information System
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ENGINEERING
FIELD
as a means of
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Engineering
Attn
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P.O. Box
Telephone
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Carroll
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Editorial
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Regional
R-1
JIM
HOGAN
Coordinators
R-2
MIKE
R-3
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CLINTON
FEHR
R-4
TED
WOOD
RUSSELL
R-5
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R-6
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ENTOEAGRIE
Tf.NI
At
IWORMATION
Volume
17
September-October 1985
Engineering
Field
Notes