United States
Department
of
Agriculture
Forest Service
Engineering Staff
Washington
UrSEs
D.C.
E ngine_e r ing
Field Notes
Volume
17
July-August
1985
Engineering Technical
Information System
Era.ý
Effective
Information
Management
Removing Protruding Rocks From
Roadbeds
Ditch Lines
Side-Looking Airborne Radar
Resources Management
in
Natural
Family Curves for Estimating Single-Lane
Road Capacities
The
Slide
Rule A Post-Mortem
Ups
Engineering Field Notes
Administrative
Professional
Distribution
Development
Ser-vice-U.S.
This
is
an
administrative document that
publication
for the guidance
of employees of the Forest
was
developed
Management
and its
Department of Agriculture its contractors
Federal and State Government Agencies.
The text
cooperating
the personal
in
the publication represents
of the
opinions
recom-mended
instruc-tions
authors. This information has not been approved for
respective
Data
Retrieval
to the public
distribution
and must not be construed as
approved policy procedures or mandatory
except
by Forest Service Manual references.
or
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
or
or
its
of
Agriculture
or application
own employees. The
of firms or corporations
use
is
assumes
of this
of
trade
for the
reader such use does not constitute an official
approval
by the United States Government of
service to the exclusion 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
publication to the following address
FOREST SERVICE-USDA
Engineering
Attn
M.J.
P.O. Box
Telephone
Staff-Washington
Carroll
D.J.
Baggett
Office
Editor
Editorial
2417-Washington
Assistant
D.C.
20013
Area Code 703-235-8198
about
this
Effective
The
CHALLENGE
Information
Management
The challenge of sharing information can be a great
one--in the Forest Service as anywhere.
It seems
is
barrier
between
those
having
there
always a
information and those needing information.
Among
are
the greatest barriers we must overcome
information
attitudes and policies concerning
information--and
in-house
exchange--especially
review processes that stifle creativity and mold
information over time into obsolete data.
restric-tive
atmosphere in which information can
freely we first need to take a hard look
the barriers exist and
then how we can get
the
unnecessary ones in our workplace.
create
flow more
To
why
rid of
at
RISK VERSUS
CONTROL
an
First effective
no
management
matter
what
we
are
managing calls for us to examine risks and controls.
have
including the Forest Service
Many agencies
traditionally imposed strong internal controls for
review processes the Directives System in
order to minimize risk waste
loss abuse.
example
declining resources however
the
risk/control
reevaluating
relationship with respect to its major activities.
this relationship in order to manage
It is examining
that is not overmanage or undermanage.
effectively
As indivi ual employees it is just as important
that we evaluate the risk/control
relationship in
managing our day-to-day activities mindful of the
In addition
level of risk we are willing to accept.
FSM 1400 now makes it our responsibility to take a
hard look at the controls we impose and to challenge
In the present era
the Forest Service
of
is
them
1
2
3
Challenge
the
necessity
Challenge burdensome
external agencies.
of
requirements
Challenge WO/RO processes
up to Forest discretion.
1
forms and reports.
that
are
imposed
better
by
left
4
Challenge quality standards
more costly than needed.
examine the
risks we are
probably find that
can reduce controls
eliminate some.
INFORMATION
EXCHANGE
ACTIVITIES
that
Once we
controls
to
willing
in many
significantly--and
the
are
higher
and
we impose in relation
to accept
we will
of our activities
we
maybe
even
One example
of the
risk versus control relationship
that all Forest Service Engineering
units should
examine is that of information exchange activities.
With the growing importance
of technology
transfer
and
throughout the Forest Service see FSM
Engineering
1320
imperative that we
use available technical data systems
and
supply input information to those systems
FSM 7113 in as unencumbered a manner as possible.
If we examine
the
level of control we impose on
these activities we may find that we sometimes
actually hinder the fulfillment of the Forest
Service technology
transfer objective--to
promptly
and
useful
efficiently apply not control
and
FSM 13320.
The many
knowledge
technology
controls we impose in relation to the few and small
risks involved
in exchanging
Engineering information
are actually blocking
the
flow of the information we
especially
be able to
all
in
it
is
need.
Having examined the risk/control
relationship we
will find that we can and should begin to relax
controls over much of the information we want to
share.
This should help free up those resources
necessary for achieving results and making our
agency more productive.
publica-tion
Applicability to EFN.
For its part the Washington
Office Engineering Staff has examined the review
process it uses for articles submitted for
in Engineering
Field Notes.
In the future
reviewers will check articles for
and accuracy as before
appropriateness policy
if they come upon any differences
between
however
an authors views and established
policy technical
reviewers will simply attach
opinion or accuracy
view-point
an
introductory
paragraph explaining the WO-E
the article will then be published
with
introductory
paragraph.
2
the
this process will help get Engineering
We believe
information into the hands of those who need it more
quickly with fewer resources being used to get it
there and perhaps with more than one viewpoint
expressed.
SUMMARY
Forest Service Engineering units at all
encourage
levels to critically examine their policies and
in the
attitudes toward controls--especially
area
of information exchange
and
the
systems they use
information
that
is
to be
for reviewing
in-house.
We will find once we begin
to impose only that control
necessary to avoid
that
the
risk
unacceptable
process of exchanging
become
easier
and faster
and
that
information will
both the agency and the public will benefit.
We
shared--especially
D.
Carroll Editor
3
4
Removing
Roadbeds
Protruding Rocks
Ditch Lines
From
Larry Leland
Supervisory Civil Engineer
Forest
Monongahela National
Region 9
Forest Road No. 91 on the Monongahela National
Forest
is
in West Virginia
a 10.4-mile-long
aggregate
surfaced road that is designated
as Maintenance
Level 4 means that the road is
Level 4.
Maintenance
for
designed
passenger car use and user driving
Over
the years however
Forest Road No.
comfort.
from
frost
road
91
became a very rough
heaves
surface erosion increased traffic volumes decreased
maintenance low standards of initial construction
Surface rocks and
and other contributing
factors.
The most
ledge outcrops protruded in many areas.
effective
way to improve the roadbed seemed to be to
remove the worst protruding rocks break up the
large flat surface areas of exposed ledge and apply
1-inch crusher-run
limestone aggregate surfacing
material where needed.
men spent 2 days walking the road and painting
green spot on the top of each rock or ledge section
that needed to be removed.
They numbered every
tenth rock to make summarizing counts per mile and
and removal rates easier.
monitoring verification
They identified a total of 1405 rocks in this
manner.
Three
a
The
contract
were kept as simple as
specifications
Various
possible and were only four pages long.
methods of rock removal were initially considered
Bids were expected to reflect costs
feasible.
involved in using a jackhammer
or a hoe ram hand
tools and possibly explosives to remove the rocks.
Because the rocks had to be removed to only 3 inches
below the existing surface excavation
was considered
economical only for the very small rocks.
An
Engineers estimate was prepared for the project
be used.
that assumed that these methods would
Table 1 shows a list of the actual bids received
with a comparison with the Engineers estimate.
5
3
Table
1.--Bid opening
results
September
21
1984.
Comparison
with
Engineers
Source
estimate
of
estimate
Bid
Sunrise Construction
Co. Inc.
Staunton Paving Company
Inc.
Sikora Construction
Company
H.
K.
Belcher Contractors
Triple H. Construction
Williams
Rinker
Richard 0. Harper
Rolan McQuain
$11610.00
$16500.00
$16695.00
$19100.00
$20600.00
$21840.00
$21986.00
$34900.00
Engineers
$21087.00
Estimate
percent
-45
-22
-21
-9
-2
4
4
66
The
low bid originally was considered
an error but
contractor verified that the bid was realistic
and that he intended to make a fair profit on the
Because the Forest Service had no other
project.
basis for rejection the award was made on September
the
28
1984.
Michael
Officer for the
Cunningham was Contracting
Sanders was the Contracting
Officers
and
Clarence Arbogast was designated
The contractor attended
Project Inspector.
the
on October
9
and was ready to
prework conference
start work the following
The contractor
morning.
used a crew of six very hard-working and capable
The job foreman worked
men.
along with his crew as
a laborer and
coordinated
activities.
Work
in a smooth and
and all work
orderly manner
was completed in only 6 working
A final
days.
was completed on
inspection and project acceptance
October 17.
The two primary reasons for the success
of this project were that the
contractor had his
equipment materials and labor lined up in advance
so that he did not lose any time and that he
selected a mix of equipment to handle the job.
project Thomas
Representative
pro-gressed
The contractor used one piece of equipment no one
else had considered--a
Vermeer rock cutter saw see
which is used primarily for cutting
figure
The contractor
grooves in concrete
used
pavements.
the saw most effectively
in areas with heavy rock
1
6
4
_
14
7
r
r
b
b
r
C
r
V
Figure l.--Vermeer
M-475 equipment
with
rock cutter
saw
dozer
and backhoe
blade
bucket
ttachments.
Table 2 gives a breakdown
ledges.
of
equipment actually used on
types
of rocks
estimated
the project
and
an
percentage
with
removed
each type.
concentrations
of the various
Table
2.--Breakdown
or
of
equipment
and
rocks
removed by
Estimated
percent of
rocks removed
Equipment
type
Vermeer M-475
cutter
rock
each
type.
Estimated
number of
rocks removed
40
562
30
422
25
351
4
56
1
14
100
1405
saw
Jackhammer
backhoe
Case
580
Hand
tools
Vermeer M-475
dozer blade
Total
7
Generally
any rocks not easily removed by hand
tools or with the backhoe were broken up and removed
with the jackhammer.
The bigger
clustered
rocks
groupsof smaller rocks and most of the ledge areas
were shaved to at least 3-inches below the existing
The
grade with the Vermeer saw see figure 2.
Vermeer front-mounted. dozer blade was used in only
area of continuous
one
ledge that was fractured
A total of 78 tons of 1-inch
enough to be rippable.
crusher-run
limestone was used to fill all the holes
resulting from the rock removal process.
tele-phone
The
Vermeer
saw was rented
Sales and
Manager Vermeer
Inc. Washington
from Rick Farrens
Service of Southern
43160
Court House.Ohio
Ohio
the
number is 614 335-8571.
The rental rate was
per week plus the replacement cost of the
cutter teeth.
The
108 carbide-tipped
teeth on the
blade cost approximately $5.00 each
and
the
went through about one and one-third
times
the
life of the teeth.
He completely
replaced the
teeth once toward the end of the project.
con-tractor
$1000
Although
rock-removal contract
was considered
first of this kind on the
was the
and some changes should be considered
for
rock-removal procedures
this
it
successful
Forest
future
1
For esthetic reasons green paint was used
mark the rocks.
White paint would
show up
better.
to
7ý
r
iF
E
ýýti
t
n
t
ý
r
Figure
ledge
2.--Before and after photos of the
The
circular blade
can swing
rock.
Vermeer
sideways
8
M-475
saw
cutting into a
while
rotating to gouge
section
wide
a
of
exposed
groove.
2
3
4
5
6
The
For a
road was closed to through traffic.
satisfactory alternative
post signs warning of
road machinery and limit traffic delays to no
more than 30 minutes.
Most traffic delays
would be 5 minutes or less.
Prevent persons
the operating
and
vehicles from approaching
Vermeer saw and possibly being struck by flying
rock chips.
diffi-cult
contract
was awarded at the start of the
fall foliage season and partial leaf cover on
the
roadbed made some painted rocks more
to locate.
Although
numbering every tenth
rock allowed for quickly verifying that all
in the
rocks were found working
spring or
low-use
would
have been
a
period
summer during
easier.
The
Only excavated. holes were backfilled with
The contract
1-inch crusher-run
limestone.
also should have provided for filling existing
potholes as well.
Several of the ditch lines had ledge outcrops
that were fairly continuous
for 10 to 100 feet.
marked
various
sections of
Although
paint spots
these outcrops and they were adequately
removed
it would
have been more practical to have a
and
separate payment item for ditch excavation
basis.
pay on a linear footage
that consisted
few short sections of roadbed
difficult
of fractured
to mark with
ledge were
individual
A more
method.
the
rock count
be
practical approach
might
stationing or road
measurement
to
length
identify the location and
a contract
provision to remove all rocks of a
certain size or surface area within that marked
section.
A
The
cost to remove each rock or section
of
average
ledge and replace it with suitable backfill material
was $8.26 $11610/1405
rocks.
Considering the
resulting improvement of the road surface this
The rock-removal procedure
appeared to be a bargain.
not only immediately improved rider comfort it also
provided the long-term benefit of a more easily
The road can be graded more
maintainable
surface.
9
Better crowning or
efficiently and effectively.
in the ditch
insloping and removal of rock blockages
lines will improve drainage.
of
Future applications
surface material will stay in place because ledgy
areas where gravel has a tendency to roll off were
broken up.
All things considered
this rock-removal
procedure proved to be an economical way to improve
the riding comfort and maintainability
of a very
rough
road.
10
Side-Looking Airborne Radar
in
Natural
Resources Management
Jerry D. Greer
Project Leader
Nationwide
Forestry
Applications
Program
airborne radar SLAR is not commonly
Side-looking
used by Resource
The system is an
Managers.
advanced
unit that requires
complex high-technology
users to be knowledgeable before attempting
to use
it.
The first step in being knowledgeable
is being
aware.
The purpose of this brief review is to inform
readers that the system does exist and is being
used.
This article contains a review of how SLAR
was used during
the Mount St. Helens eruption and
discusses some current applications.
of special project
imagery is complicated
Acquisition
the
fact
that
by
the system is not
in common
use.
However radar sometimes may be the most efficient
solution to management
information needs.
That
determination
is yours to make.
The eruption of Mount St. Helens provided a unique
technology
opportunity to apply currently available
information was needed
in a situation where accurate
condi-tions
immediately.
days after the main eruption weather
ash cloud presented
effective
barriers
the
data by aerial or high-altitude
to gathering
assessment
Ground hazards prevented
quick
The
teams from getting data by foot or vehicle.
need for data was met within 3 days by acquiring
high-altitude side-looking radar imagery.
For 30
photog-raphy.
and
Active radar was chosen as the remote-sensing system
clouds
because of its unique ability to penetrate
haze dust and most materials that block the passage
of light waves.
radar
imagery produced
by a high-resolution
conditions.
ground
accurately
depicts
system very
The
sensor used on the Mount St. Helens project was
a modified
unit which has a
Goodyear APQ1102
The
11
resolution of less than 50 feet.
The reproduction
of the radar image in figure 1 shows very clearly
how geologic features are shown.
The presence of
clearcut blocks roads and streams are obvious even
to the untrained
the
analyst.
Although
image looks
like an aerial photograph
it is not--the area was
completely obscured by ash dust and clouds when
this image was acquired.
Microwave
pulses emitted
at different
by the radar transmitter were reflected
These reflected
angles by different materials.
signals were displayed on a cathode
ray tube and
recorded
film for interpretation
and
on photographic
use.
radar units can be carried by aircraft
Side-looking
or space shuttles.
At Mount St. Helens
Air
a U.S.
Force high-altitude
reconnaissance
aircraft carried
the
unit.
available for several
New England New
area.
Jersey Virginia and the central Appalachian
This imagery was collected from 1980 to 1982 using
airborne units flying at medium altitude.
Side-looking
locations in
radar imagery
Alaska Nevada
is
The first space shuttle experiment was in 1981.
Shuttle Imaging Radar-A proved that the system could
be used effectively
from space orbit.
More recently
Shuttle Imaging Radar-B was used during the October
1984 space shuttle mission.
Scientific
evaluation
of that data continues
at this time.
Mount St. Helens eruption provided an opportunity
the dramatic application
of technology
to assess
less
damage to resources and facilities.
Though
4
later
is
more
dramatic the technology
even
years
advanced and applications
in resource management
The system is especially
problems are more common.
valuable
in efforts to map terrain with a nearly
cloud cover.
Because of image
perpetual
radar is very useful in geologic studies.
in
Tectonic
features are unusually clear especially
areas of low relief.
Radar often yields more
detail than does normal aerial
Radar also has been used successfully for
vegetation
crop identification
mapping locating
clearcut areas assessing land uses and mapping
snowfields.
The
for
character-istics
geo-morphological
photog-raphy.
12
of radar remote-sensing
use
systems which can
used as stand-alone systems continues to receive
Haack used the numerical data
.increasin attention.
in much the
same way Landsat data are used in
There also is a
of urban environments.
in
in
radar
interest
using
systems
growing
Rosenthal
with other remote-sensing systems.
The
be
inves-tigations
conjunc-tion
classifica-tion
crop
improved vegetation
73
92
from
to
percent by using
accuracy
percent
radar data combined with data in the visible and
infrared portions of the electromagnetic
spectrum.
alone
or
The use of radar remote-sensing
systems
and
with
Blanchard
other
inventory
systems has potential
faced
problems
by
and
in management
foresters.
Readers
who want more detailed but layman-friendly
descriptions of how side-looking radar systems
operate should refer to Side-Looking Airborne Radar
Readers who want
by Homer Jensen and others.
technical
information
should refer
state-of-the-art
Remote
second
edition
of
the
Manual
of
to the
Sensing by Robert N. Colwell.
REFERENCES
Colwell
R.
Manual of Remote Sensing
VA American Society of
N.
2nd
ed.
Photo-grammetry
Falls Church
1983.
Haack
X-band-like
and
cross-polarized
urban
radar
for
investigating
synthetic aperture
environments.
Journal of the American Society of
L
Marc. 1984.
Photogrammetry
B.
Jensen
L-
N.
H.
et
Scientific
Rosenthal
W.
and
airborne
Side-looking
October 1977.
al.
D.
and
Blanchard
microwave
an
responses
classification.
Journal
of
radar.
American
Photogrammetry
13
L
aid in
of the
April 1984
B.
J.
Active
improved
American
crop
Society
.
M1
r
a
ý
/fig
x
r
aX
k
t
t
tti
aýý4
tl4ý
1
Figure I.--image of
Mount St. Helens area
made by a side-looking
airborne radar unit.
Radar
U.S.
image
by
the
Air Force.
14
ahýMýi
4
as
a
ýmxeiC
-
ýYr
\
5
0
x
titýI
w
a
ýý
NI
iltý
15
y
Family Curves for Estimating Single-Lane
Road Capacities
Fong L. Ou
Engineer
Systems Operations Analysis
Ken Tompkins
Chief Engineer
Preconstruction
Transportation
Office
Washington
Development
Design
char-acteristics
A
C
This article presents four capacity
estimate family
the
for
roads
with
general
curves
single-lane
and
of traffic service levels
B
under
volumes
observed
The
actual
D.
curves depict
controlled
conditions and provide for extrapolation
This
volumes under the same conditions.
to higher
article describes how capacities of single-lane
techniques.
roads can be maximized through control
INTRODUCTION
1982 Region
6
and the Washington
Office initiated
Mount St. Helens traffic study.
The purpose of
was
to
collect
data
from
roads
with heavy
study
from
timber
from
traffic resulting
moving salvage
the volcanic
damage area.
In
the
the
The
in
preliminary result of the study was reported
in
of Road Design on Timber-Hauling
Speed
the United
States Transportation Research Record
1983. The articles Identifying Road Capacity
Field Notes
Traffic
Service Level
in En ineerin
Volume 16 April-May 1984 an
Evaluating Capacities
of One-Lane Roads with Turnouts
in Transportation
Research
Record
1984 provide additional
information about this study.
Effect
898
971
capac-ities
The
purpose of this article is to develop a set of
family curves for estimating single-lane road
under certain controlled conditions.
A sample
collected from four study sites in the Mount St.
Helens area was used to develop the curves which
were then verified by a second sample collected from
the same study area.
17
DATA
The
April-May 1984 issue of Engineering Field Notes
reported the procedure for collecting the data and
the
road characteristics
of the
The
study sites.
four road segments selected for this study were
sites 17 20 26 and 33.
The general road
of these sites are described in table 1.
charac-teristics
condi-tions.
table 1 the data include traffic
traffic composition
and weather
The duration of each traffic count was
2 hours
and the average
approximately
volume ranged
from 13 vehicles
per hour vph.on site 26 to 39 vph
on site 33.
Empty and loaded log trucks accounted
for approximately
50 to 70 percent of the
total
traffic.
The portion
of other trucks
deviated
greatly ranging from 3 percent on site 33 to 19
This discrepancy
percent on site 17.
resulted from
the
reconstruction of a road segment near site 17
when the traffic count took place on June 17 1982.
The portion of Forest Service light vehicles
varied
from 3 percent on site 17 to 11 percent on sites 20
and 26.
No recreational
vehicles were observed
because the road segments in the study area were not
open to the public during the study period.
As
shown
in
volume
By using the data collected from each site the
duration of the traffic count was broken down into
several intervals with each interval containing
an
independent continuous
flow.
The gaps between
intervals are more than 4 minutes and the intervals
The average
range from 5 to 35 minutes.
hourly
volume was expanded from the traffic of each
interval.
The
four variables for the analysis are speed
general road characteristics and the
traffic directional distribution.
The traffic
directional distribution is the percentage
of
traffic in the heavy traffic direction relative
to
the
total traffic.
The ratio is 50 percent when the
traffic in opposite directions is equal.
On the
other hand the ratio is 100 percent if traffic
flows solely in one direction.
Most vehicles
were
When traffic conflicts
equipped with CB radios..
occurred loaded log trucks had the right-of-way and
other vehicles were required to yield the way by
using turnouts.
volume
18
4
28
3
Cloudy
5
23
Clear-warm
visible
Cloudy-rain
0
21
Partially
3.9
Inter-
20-50
Gravel
7
21
Clear
6
30
45
0
16
7
0
3
40
37
p.m.
p.m.-310
cloudy
5.8
Low
20-50
Gravel
4
fog
with
visible
3
Clear
6
39
Average
j
39
21
0
0
32
47
27
41
31
0
26
1982
550
a.m.
38
19
1
0
inter-August
6
18
43
p.m.
1982
1100
1982
July
28
July
26
200
Overcast
Clear-warm
Cloudy-cool
Clear-warn
visible
5
34
24
29
July
1
1982
800
a.m.
37
17
7
0
Average
13
38
11
0
0
1
44
17
a.m.
520
1982
26
August
33
mile.
per
radius
to
the
number
of
curves
4
40
30
July
28
1982
1201
p.m.-210
p.m.
13
41
31
0
7
17
0
a.m.-1053
12
30
23
visible
19
32
13
a.m.-1020
a.m.-210
28
0
10
23
10
a.m.
753
1982
30
June
a.m.-850
5.9
Inter-
50-100
Paved
0
32
12
0
0
11
32
20
Average
a.m.-1120
4.1
Inter-
20-50
Clear-wars
Paved
49
24
0
Patchy
18
0
33
0
20
0
8
24
17
a.m.
a.m.-820
550
1982
25
August
26
a.m.-135
a.m.-200
vehiclesvehicles
Turnout
grade
Surface
menta
tions
truck
truck.
truck
trailer
July
28
1982
620
a.m.
16
37
16
8
June
29
1982
1244
p.m.-320
p.m.
30
36
3
Average
32
22
4
34
29
2
17
31
p.m.
1015
1982
25
August
20
a.m.-840
Align-
condi-
Other
log
log
with
volume
p.m.
1057
1982
17
June
17
by
the
ratio
of
the
average
Percent
Weather
Loaded
Empty
Service
vehicle
Duration
tion
light
Light
hourly
count
observationtraffic
Road
percent
Recrea-Forest
Average
of
of
Date
Site
aDefined
Characteristics
1.--Datacharacteristics.Trafficcomposition
Table
co
FAMILY
CURVES
the
four variables speed
volume and traffic
directional distribution are quantitative
and were
measured based on the traffic count.
The following
mixed-logarithmic equation was used to develop the
Of
curves
-
a1C
Z
a0
Z
a
U
average
C
traffic
-
a2V
where
composite
variable
speed
equal
to
U/C
mph
distribution ratio percent of
traffic on heavy traffic direction
one-way
to total traffic that
ranges from 50 to
100
C
logarithmic
value
of
C
vph
V
volume
a
constant
to
be
estimated.
Figures 1 through 4 show four sets of family curves
for single-lane
roads with characteristics
of traffic
service
leve-is
C and D. The solid line
represents actual observations and the dotted line
describes the curve simulated beyond the observed
conditions.
A B
indicates that the effect of changing the
directional
distribution from 50 percent to
100 percent causes the
speed to vary by as much as
6.5 miles per hour in a low-volume
condition
10 vehicles per hour and less. This effect tends
to decrease as traffic volume
increases and speed
decreases.
The curve characteristics
of figure 1
also apply to the curves of figures 2 3 and 4.
Figure
traffic
APPLICATION
1
The
curves were applied to a second sample
developed
five sites selected from the study area.
The
result was satisfactory with an average
error rate
of 10.5 percent.
However the error rate of one
site was nearly 25 percent because the sites design
standard differed significantly from those described
in table 1.
of
20
-C
40
-NNW
-ftft
MrW
MI-ft-ft
100
----
9 0
80
-70
60
150
35
C
30
E
Percent
of one-way
traffic on heavy
traffic direction to
total
traffic.
- Curve
a
within
the
of base
range
condi-tions.
2 5
-
- Curve outside the range
of base conditions.
20
Controlled
Traffic
Condition
a.
b.
10
20
30
Volume
Figure l.--Capacities of
A.
traffic service level
40
50
60
CB
No
radio
public
traffic
70
vph
single-lane roads
with
21
characteristics
generally associated
with
C
40
Percent of one-way
traffic on heavy
traffic direction
traffic.
total
Curve
to
within the
of base
condi-tions.
range
_-.Curve
35
t
outside the range
base conditions.
of
30
E
ft-ft
V
C
ft-ft
W
100
QO
80
70
CL
60
50
25
20
Controlled
Traffic
Condition
a.
b.
15
10
20
30
Volume
40
50
CB
No
radio
public
traffic
60
vph
Figure 2.--Capacities of single-lane roads
traffic service
level
B.
with
characteristics
22
generally associated
with
C
30
Percent of one-way
traffic on heavy
traffic direction to
traffic.
total
Curve
within
of
the
base
condi-tions.
range
25
--Curve
of
0.
20
outside the range
conditions.
base
100
C
90
80
70
60
50
15
Controlled
Traffic
Condition
a.
b.
10
10
20
Volume
Figure 3.--Capacities of
C.
traffic service level
30
40
CB
No
radio
public
traffic
50
vph
single-lane roads
with
23
characteristics
generally associated
with
Percent of one-way
traffic on heavy
traffic direction to
traffic.
total
C
30
Curve
within
the
base
condi-tions.
-
25
E
-
range
of
Curve
outside the range
conditions.
of
base
20
aa
100
90
80
15
70
60
50
10
Controlled
Traffic
Condition
a.
b.
10
20
Volume
30
CB
No
radio
public
traffic
50
40
vph
Figure 4.--Capacities of single-lane roads
traffic service
level
D.
with
characteristics
24
generally associated
with
The first sample collected
from the Mount St. Helens
area was used to develop four sets of family curves
for estimating capacities of single-lane
roads.
In
this context capacity
was defined by speed
volume
traffic directional ratio and general road
A second sample collected from the same
study area was used to verify these curves
and
the
result was satisfactory.
the
curves
were
However
from a limited sample of the Mount St.
developed
Helens area and they have not been tested in other
areas so experimental use of these curves requires
verification
with local data samples.
charac-teristics.
25
The
Slide
Rule
A Post-Mortem
Jerry D. Greer
Project Leader
Nationwide
Forestry
Applications
CONCLUSION
Program
I
admit to knowing
less than I should about slide
rules.
Entering forestry instead of engineering
probably had something to do with that.
When
I
approached
college my dream was to become an
engineer involved with physics and chemistry.
Part
of that dream was to have a
duo-quad-maxi-flex-deci-duce-hex-trig
slide rule in a firm leather case.
my college
years I never obtained a slide
rule like those shown in all the catalogs I
collected.
I
eventually picked up a student model
Post rule and learned to read it to a
decimal place or two.
Later
I
found a pocket model
g10
of a Dietzen and
4S
took it under
.Durin
my care.
0
When I say found
thats exactly what I
out-side
s
This little slide
mean.
in its 6-inch leather case was
the ground near a trash can
rule
lying on
student
to the
trash can was
were on the horizon
the
trend.
union building.
Its proximity
significant.
Pocket
calculators
then and I should have seen the
After
graduation my fortunes improved.
My income
suddenly exceeded the amount I needed to live.
Despite the rational logical
and it turns out
well-founded
objections of my wife I followed my
dream and with a sense of brash well-being I
purchased
my duo-quad-maxi-flex-deci-duce-hex-trig
slide rule.
I
it for 20 percent
off out
got
of a
mailer
that
special
nearly pleaded with me to buy
it.
It was a jewel.
The clean white plastic held
the sharply incised lines.
I
could easily read the
The slide moved effortlessly as my
tiny numbers.
27
hands
moved
bar left and right.
I
rattled off
and
cubes.
products
My 3-year-old son
the
tangents
impressed
was
My wife in the meantime had acquired a small
hand-held
I was heartless
in my
calculator.
criticism of its glaring boxlike red numbers.
Where is the skill I asked.
me that
She.informed
skill wasnt important results were.
Subtract
I
these two numbers she challenged.
grabbed
my
slide rule.
Realizing its limitations I then dove
The answer is ---- she
for a pencil and paper.
and
to rattle off some number
answered
proceeded
with a thousand decimal places.
Thats probably
love affair with a slide
rule began to fade.
What was a forester doing with
became
one anyway
It
easy to sneak into the desk
her
drawer and use
little calculator.
My slide rule
in
I
lay dormant
my night stand waiting
suppose
It
for some resurrection
never came.
signal.
where
my
that
No
pun intended
but
of
other
mementos of my passage but
dont know where it went and
duo-quad-maxi-flex-deci-duce-hex-trig
slide rule is one of the few
Ive saved
things Ive let slip away from me.
junk
as
I
escaped.
just
exists only as a memory.
tons
it
now
After
Its probably near my abandoned typewriter.
all this word processor did turn out better than
it
I
You should have seen me knock that
expected.
Thats another story though.
Now where
concept.
Take it from me
is my notebook
and Abney level
those newfangled
electronic
notebooks
will never
survive in this cold world of common sense.
WO-E
NOTE
To a certain
degree we all are guilty of rejecting
innovative
ideas for the comfort and feeling of
the
But we must accept
security of our old ways.
fact that there is usually a better way to do almost
anything and then start looking for that better
With the declining resources we are provided
way.
to get
our jobs done its a must
28
Ups
f
The Series
Engineering Technical
Information System
THE
NOTES
ENGINEERING
FIELD
as a means of
SERIES
is
published
exchanging engineering-related
ideas and information on activities
problems encountered and
solutions developed
or other data
that
may be of value to
periodically
Engineers Service-wide. Articles are usually less than six pages
and include material that is not appropriate for an Engineering
Technical
Report or suitable for Engineering Management
1630 and
publicationsFSM
Distribution
Each
at
Notes
Field
edition
is
as well as to Forest Service
the Field
is not receiving
Information
Regional
copies
Information
Technical
Submittals
Every reader
is
news
Engineering
Retirees.
If
your office
your Office Manager
increase the number
to
or
of
Copies of back issues are available in
the Washington
Office
Engineering
from
quantities
Staff
and Area Headquarters
Notes ask
Coordinator
for your location.
limited
to the Engineering
distributed
Forests Stations
Offices
Regional
7113.
Center.
a potential
author of a Field
Notes
article.
you
If
item or short description about your work that you
to share with Forest Service
Engineers we invite you to
have
a
wish
submit the
article for publication.
Personnel
Field
send
should
material to their Regional Information Coordinator for review by
the Regional
Office to assure inclusion of information that is
accurate timely and
news
include
short articles
and
Type the manuscript double-spaced
drawings and black-and-white photographs if
original
only color photographs
negatives
Inquiries
Service-wide
of interest
items are preferred.
Information
Regional
publication and
publishing
direct
send transparencies
are available
and two machine copies
Coordinators
questions
should
concerning
schedules etc. to
or
of the manuscript.
send articles for
format editing
FOREST SERVICE-USDA
Engineering
Attn
M.J.
P.O. Box
Staff-Washington
Carroll
D.J.
Baggett
Office
Editor
Editorial
Assistant
2417-Washington
Telephone
Regional
R-1
LARRY
Coordinators
R-2
MIKE
R-3
JOHN
D.C.
20013
Area Code 703-235-8198
BRUESCH
CLINTON
FEHR
WOOD
R-4
TED
R-5
PHIL
R-6
KJELL
R-8
JIM
R-9
RUSSELL
BAKKE
R-10
WO
FRED
RON
AL
HINTSALA
HAYDEN
COLLEY
GILPIN
U.
S.
GOVERNMENT
PRINTING
OFFICE
1985
527-546/30503
05T
.
SE2viC
p4s
1MENTOFA08
CJ
EERING
TECHNICAL
INFORMATION
L77ý
Volume
17
July-August
1985
Engineering
Field
Notes