s
ENGINEERING
TECHNICAL
FIELD
INFORMATION
REPORTS
TECHNICAL
NOTES
TEXTS
CURRENT AWARENESS
DATA RETRIEVAL
SYSTEM
VOLUME
Field
-d Mountain
Survey/Design
Washington
1
1
Writer
Stringer Bridge Inspection
Analysis
Notes
------
oa.
Log
NUMBER
Creek Soil Bridge
Engineering
Output
7
in
and
Alaska
Office
Engineering
News
FOREST SERVICE
U.S.
AUGUST
1975
DEPARTMENT OF AGRICULTURE
fORM
uýs
ENGINEERING FIELD NOTES
This
publication
among
The
Forest
text
the
a
Because
of
the
and engineering
this
publication
This
monthly
not
is
not
of
technicians
is
the
exchange
to
nature
Department
interpretation
of
or
of
recommended
material
should
the
in
read
or
by
FSM
publication
all
or policy
except
each
issue
however
exclusively for engineers.
published
this
employees of
for distribution to
Service and
no
assumes
Agriculture
use
as
of the
opinions
personal
construed
instructions
type
intended
newsletter
be
Department of Agriculture-Forest
U.S.
published
technical or administrative
represents
must
and
procedures mandatory
engineers
The
publication
author
references.
the
newsletter
and ideas of
Service personnel.
in
respective
approved
monthly
a
is
information
engineering
information
its
retirees
by
other
only.
for
responsibility
than
its
the
own
employees.
The
use
of trade firm or corporation
convenience
evaluation
any product
of
the
reader.
conclusion
or service
Such
use
names
does
recommendation
to
the exclusion
is
not
for the information
constitute
endorsement
of others
or
an
approval
which may be
and
official
of
suitable.
Figure
1.
Completed
Mountain
50
ft.
Creek.
x 10
Note
ft.
the
U.S.
Steel
Reinforced Soil Bridge
end diaphragm
protruding
i
Figure
2.
Original steel truss bridge
Inventory
rating for
HS
across
loading
across
through
f
Red Mountain
is
3.3
tons.
Creek.
the
Red
fill.
RED MOUNTAIN
Robert M.
Civil
CREEK SOIL BRIDGE
Leland Fansher
Willis
Engineer
Civil
Rio Grande
National
bridges
for use
as
stream
in
spans
Douglas Studs
under the trade name Reinforced
the
timber
now
Rio Grande
developed
Forest
National
and Mineral
purchaser
arches manufactured
At the time of
Soil Bridge.
to
alternate
limits.
previous
the
Inc.
one of these long span
constructed
an
as
have
manufacturers
steel
greatly exceeding
1973 and the spring of 1974
with
cooperation
County
of
fall
Several
feet.
available
steel arches have been limited
Until recently
crossings.
25
modified arches with
During the
plate steel arches have been
structural
not exceeding
to spans
Forest
2
Region
For many years
Engineer
by U.S.
Steel
the
construction
its
ex-isting
alterna-tives
Red Mountain Creek
10-foot
rise
Soil Bridge
combination
Plans for the Soil Bridge
steel
truss
such
as
bridge
new
a
were investigated
1
first
were developed
2
fig.
truss
fig.
was the
it
was unique
indicated
analysis
that
a
50-foot
such
low-rise-to-wide-span
after
a safety inspection
to be unsafe
bridge multiple
with
for
legal truck
span
and
a
structure.
showed
the
Several
loads.
installations and the Soil Bridge
arch
the Soil Bridge
would be the most
economical.
water-way.
Hydrologic
investigations
Consequently
In
an
addition the
The
arch
the previous
size
concrete
following
is
maximum
indicated
a
with
a
footing
a
required
50-foot
steel
span
walls were
comparison of the
arch
1
waterway
of 340
and a 10-foot
raised
3 feet
to
square
rise
mold
Red Mountain Creek
was
feet.
selected.
to the
structure
with
Red Mountain
Maximum
Span
50
ft.
25
ft.
Rise
10
ft.
8
ft.
Ratio
Span
Rise
0.2
435
Waterway
344 sq
The
principle of
structural
over
the
in.
0.215
Thickness
plate
steel
the
movement and
ft.
5
in.
Soil Bridge
most of the
carries
61
in.
0.34
Arch Radius
Steel
Steel
Archl
Soil Bridge
is
that
in.
155
sq.
0.280
ga.
the
The
load.
160
arch
steel
of compacted
acts
plate
ft.
1
in.
as
a
ga.
soil
liner
de-flection.
soil
preventing
must
resist
To
prevent
Bridge
failure
design
ring
In
compression.
load
and the
during
backfill
soil
for steel bins on the
provides
arch.
design
keystone
soil
of the arch
top
soil
excessive
prevents
form a
to
the
conventional
primarily
and
of
It
the
the
Soil
illustrated
as
steel
steel
in
3.
figure
Due
and
buckling
most of the
carries
construction
permitting
to
problems
right-of-way
Thus
Creek.
it
was
possible to
not
had to be constructed
the Soil Bridge
realign
Red Mountain
on a 15
skew
degree
modi-fications.
with
the
some
caused
The
end sections
original
beveled
for aesthetic effect.
problems which
construction
envisioned
design
were
This
through
solved
skew
arches without
bevel
and skew
design
and bins fabricated
triangu-lar
treat-ment
with
square
project
U.S.
diaphragms
bins fig.
in
both
the
Iron
and road
the
bins square
road centerline
mind and
they
which
are
Steel Drainage
and Steel Institute
through
protrude
and appear
brighter
on the
not galvanized
and Highway
1971
the
in
p.
62
Max.
fill
fig.
2
x
ends
with end
designed
slope
and added
forming two
fig.
1.
the
The
original
added bins and
3.
Construction
Span
the arch
with
photo than
the
Red Mountain
For the
centerlines.
center
These end diaphragms were not
3.
bins are galvanized
1Handbook of
the
to
parallel
end diaphragms
arch
fabricated
Steel
Min.
Products
Rise.
New York
NY
American
ý4
fh
i
1
t
Figure
3.
Steel completely
erected
a
4
yy
r
ý
showing skewed
diaphragms
and triangular bins at the
en..s.
%
A
il.
h
Figure
4
Stiffeners
Backfill
added as a safety factor
lifts
alternate
taf
Ji.
from
to stiffen the structure
side to side
3
and are placed
in
during
K
.1.
backfilling.
approximately
one foot
lifts.
To
reinforce
structure
of the bins to the
top
of these
effect
the
the
arch
and the added bins
construction.
during
After
understood that U.S.
is
the
truss
to the
arch
complete
finished
which supports
the
truss
structure
no
is
be
not
will
feature to
this
The
4.
fig.
to form a truss
is
backfilling
the
destroys
If rust
ties
added from the
angles were
stiffener
backfill
with midpoint
footing
stiffeners
functional.
longer
during
Soil
shor-ing
struc-ture.
shal-low
damaged.
Bridges
The
It
is
and construction
design
was erected
shell
fig. 5.
Because
4
fig.
back down
arch
loading
and
for
footings
crane
the
minimum
the
shape
original
until
The
satisfactory.
loading
earth
with
This
the
soil
in
in
the
pushing
sidewall and
while
procedure
were
used
instruments
was
sides
literally
alternating
was complete.
only
the
This
arch
of the
backfilling
When
center.
6.
fig.
backfill
The
for
posts
portion
and compact
backfill
in
timber
steel
lateral
and bins were loaded
was continued
all
was conventional
and native
completing
to alternately
top
to the
care proved
requiring
20-ton
a
monitoring peaking
the
adding
is
concrete
place
in
designed
is
while
rose one inch
crown
level
arch
The procedure was
lifts
the
of the
were bolted
Steel
or more.
with the aid of
Bins
the steel
critical.
center
35
to span
designed
feet
a
surveyors
plumb bobs.
several
accep-table
The
backfill
was
soil
a local
from the
were removed
about 90 percent
of
by the bridge
backfill
soil
AASHTO
T-99
The
actually
Three
and were
unsupported
at
the
partial
columns were erected
covered
rocks
Occasional
near the
steel.
maximum
with
metal
corners
arches at
formed reverse curvature
steel
sand.
larger
Compaction
than
6 inches
averaged
only
but was deemed
density
designer.
Problems were encountered
angles.
fine
silty
at
the
where the bevel and skew
these corners
downward and
fig. 7.
edges
under the two
plates
deflected
formed acute
to prevent
opposite
critical
accumulation
corners
fig.
of debris fig.
8
9.
from the appearance of the bridge and also restrict the
More was
to some extent.
Figure 9 shows part of the riprap in place.
These columns detract
waterway
added since then
The
cost
estimated
of the
cost
and the exposed
structure
of
$75000
including
diaphragm of the end bins was painted.
footings
for a concrete
4
and backfill
bridge
with
was
the same
$55470
span.
versus
This
an
does
4
lY
Figure
ý
3ýý
5.
d
Native
timber
post shoring used
during
ýr
r
j
-
of the
erection
steel
shell.
z
.
y
F
rryý
loiiw
frez
ý
Figure
6.
Control
of crown
rise
by loading
5
top
of structure
with
earth.
it
-.
ý
.
Aw
T
w
fW
ý
T
-
s
Figure
7.
Failure
of
this
of unsupported
beveled
corner
and skewed
r
t
of structure. Failure occurred
at
both acute
Steel
column
supports
corners
..rt
vJ-
Figure 8.
angle
structure.
Figure
placed
under failure at corners.
si
9.
Steel support
columns
covered
steel plate
with
partially
accumulation of debris.
6
to prevent
con-structing
not
include
by Mineral
costs incurred
County
in
removing the old bridge
and removing a detour riprapping the new
structure
and
grading
final
roadway.
of the
ob-served
At the present
appears
it
Creek Project
Mountain
timber
time
and construction
can
for several
traffic
this
made
several
improvements
spans
to be built
attributed
to the
the
in
his
and skewed
structure
been carrying
has
design
ends
will
and construction
on
or deflection
be
should
this
structure.
even
permit
designer
larger
problems can be
2 would
Region
would hesitate to try one
but
Soil Bridge
The
concerned.
all
concept which
another
constructing
the
for
experience
overall
and that the Red
are reached.
conclusions
Most
sound
is
summer and no movement
and rod however
final
future.
beveled
consider
in
principle
completed Soil Bridge
the
was a valuable
Constructing
bridge
The
during
transit
before
years
Soil Bridge
a success.
is
be determined with a
the
erec-tion
tim-ber
definitely
with
either
structure
J.
D.
a
backfill.
purchaser.
Pittsburgh
ends
The
structural
Pennsylvania.
that
developed
Pictures of the
Steel
Soil Bridge
were
were both
would not consider
beveled
fabrication
used
Utah
by U.S.
recent
7
Steel
Reynold
K.
national
this
is
the
Corporation
Steel
Company of Provo
Watkins
State University
concept and designed
in
for steel
South Fork Colorado.
was by Syro
by Professor
Station
another
and skewed.
was responsible
Colorado
Industries
design was guaranteed
Experiment
bridge
The Region
Springs
was supervised
Engineering
the
end.
Southwest Forest
Construction
Director
who
with
size
Adams Company Colorado
and
Utah.
or a skewed
beveled
of this
Associate
Logan
Utah
structure.
advertising by U.S.
Steel.
ENGINEERING
ON THE
720
PROGRAMS
OUTPUT WRITER
SURVEY/DESIGN
WANG
701
-
Robert Lane
Civil
Technician
Engineering
Eldorado National
Region
The
written
number of
a
This computer
survey
check
out
run
can
errors
Our
in
As they
otherwise
crew
of our
Of
more
became
found the need
computer.
a
this
for
new
is
survey
on the
still
with
the
design
is
tool in
a large
the
of
capabilities
road-design
this
computer
Only about
lessening.
completed on the Fort
amount
would have to be performed
The solar program can
The traverse
programs
crew time to correct any
performance computer
construction
top computer.
project.
to be a handy
familiar
a higher
60 percent
very
compiled and
has
desk
with a means of checking
project.
short time.
allowing the
quickly
the
in
have found the 720 Wang
designers
60 percent
observations
while
on the
still
is
Forest
720 Wang
Section
Survey/Design
crew
survey
very
work
field
the
provided
the
traverse
programs for the
engineering
of solar
a set
the
process.
they
has
data while
5
on the Eldorado National
section
preconstruction
Forest
work
of preparatory
on the Fort
Collins
Collins
which
computer
be
can
done on the Wang.
The
traverse
checked
run.
the
before
This has
Fort
contour
reduction
submitting
sped
the
and
initial
design
horizontal
to Fort
Collins for the
can
be run and
first earthwork
of input
up the process and reduced the number
errors
to
Collins computer.
PROGRAM
PLANE SURVEY
VOL. 2
CONTOUR
700/701
SLOPE
SOLARS 14865
LEVELS
TRAVERSE
BIN
15353
% GRADE AND ELEVATION
2309
alignment
LIST
REDUCTION
DISTANCE
MILE
WALL
POST
ANALYSIS
HYDRAULIC RADIUS
PIPE 11244
8
%/
7291
2519
15778
ARCH
CONSTRUCTION
2743
AGGREGATE
8565
HAND
CLEARING
BASE
COURSE
LEVELS 1831
SURFACE
AREA
3331
PTRAVERSE
4997
PROGRAM
LIST-Continued
MANNINGS
EQUATION
HORIZONTAL ALIGNMENT
18480
EXCAVATION COST
MATE 1118083/2215
TRANSIT
NOTES/TANGENT
OFFSET x/14009
WRITING
//4290
NOMOGRAPH
CALIFORNIA
x/10705
3398
x/6579
SURVEY
EXTENDED
AREA
AREA
SLOPE
ESTI-
PACK
TRIG
SURFACE
06265
VOL. 94
ANALY-1f3248
EARTHWORK END AREA
//4690
QUANTITIES
4631/13677/676
SUN SHOT
RECONSTRUCTION
CLEARING
COURSE
BASE
1114524
115465
LEVEL CIRCUIT
AGGREGATE
DATA
113786
AREA
SURFACE
TRANSIT
//8793
CLEARING COST ESTIMATE
1/14379
1/5206
DISTANCE
119527
STADIA
QUANTITIES
1/13456
1/720/701
116015
SIGHT
1111496
% ABNEY CROSS SECTION
REDUCTION 1/2700
GEOMETRY
COORDINATE
ROD/
116453
REDUCTION
SURVEY
1/8575
COURSE
REDUCTION
CONTOUR
NOTES/CURVE
AS STAKED
113226
BASE
SIS 1/6876
112530
P-TRAVERSE
ASPHALT CONCRETE
FLOOD-FREQUENCY
VERTICAL CURVE ELEVATION
AGGREGATE
EARTHWORK
720/701
align-ment
COST
Many
of our low-standard
Wang
in
one hour.
roads
includes
Output
type
earthwork
WITH
C5-202
A-11
A-12
from chain-flag field
are designed
this
A-10
can
design
quantities
be performed
on
mass ordinates
and slope stake notes.
quantities
clearing
timber
WORK SHEET
A-10
Approximately one mile of
surveys.
the
ESTIMATE
PROGRAM/ENGR.
ESTIMATING
compu-tation
The
newest
A-12
program Cost
performs
all
shown
to date have
Results
and checking
Anyone wanting
25
of the
foot
blank
computations
that
work and
copies
cassette
Placerville California
Estimate A-10 A-11 and
Estimating/Engineering
the
for these tables
program
greatly
reduce
of these programs can
tapes to the
95667
Eldorado
will
eliminate
the
sale
many
contract.
hours
of
human-error probability.
obtain
National
Attention Bob Lane.
9
in
them
by sending
seven
Forest 100 Forni
Road
LOG STRINGER BRIDGE
Robert
Willis
Engineer
Civil
Tongass National
problems associated
every bridge
inspecting and analyzing
with
Log
engineer.
Forest
10
Region
The
AND ANALYSIS
INSPECTION
ALASKA
IN
bridges
stringer
confronted
have
bridges
on the
located
Alexander
of the
islands
limi-ted.
al-lowable
of southeastern
Archipelago
in
bridge
The
engineering.
knowledge
current
Alaska
Figures
1
several
pose
through
of log stringer
problems not
bridge
normally
examples of log
3 are
stringer
and design
analysis
encountered
bridges.
somewhat
is
An-other
Pre-liminary
Our team had
bending
was
critical
The
was assumed
to be 1600
psi
a
similar
value
These values were recommended by the Forest
used.
also
Madison Wisconsin.
Laboratory
Products
several
of Sitka Spruce
stress
hemlock
for western
make
to
assumptions prior to anaylsis.
These two
species are the
only
ones
de-termine
currently
used
being
for bridge
assumption was the
of the
vehicle
load
is
the
in
National
Forests
of Alaska.
to the
applied
stringers.
Laboratory has indicated that 30 percent
recommended
are constructed
the
in
distribution factor
Products
distribution to each
was
distribution factors
live-load
log bridges
live-load
by the Forest
testing
construction
required
also
Testing
stringer.
of the
because
to
unique way
Alaska.
sur-face.
Construction
6 inches
A
mat.
to
to large
same
cable
of
as
end when
curbs
factors
around the
on most
placed
area throughout
stringers
The
bridge.
this
program
type
is
now underway
logs
method
Of
the
to correlate
of bridge.
10
this
side
under
form a
running
Brow
load.
are alternated
gives
to
stringers with
small end
approximately the
150 log bridges
of Sitka Spruce
constructed
the
to form the
placed
stringer
by
side
between
for stabilization
construction
the
one was composed
but
to chink
broken rock
bridges.
This
are placed
Stringers
on Baranof Island which was
field testing
for
all
are then
material
constructed.
cross-sectional
was a bridge
poles
cover
wrapped
is
team analyzed
1A
Filler
3 feet
are added
logs
simple but functional.
is
continuous
logs.
of western
The one
that
our
exception
hemlock.
data as well as live-load distribution
lo-gistics.
in-spection
The
the
Getting
and
or boat
plane
transportation
severely
into the
felt
the
with an
drill
as
fast
the
as
favor
in
to bore
the
of a 16-inch
electric
drill
The
first
stringer
In the
area the
first
needed was
on hand.
In
of our gear could
all
used
only
showed
quickly
us
a portable generator
electric
increment
to locate
in
be accomplished by
This method of
of initiation
This
logs.
easier
it
only
are used.
week we
hand-operated
and made
can
and
Our week
was a problem
sites
everything
Three people
available.
was impractical.
electrical
that
and challenging
interesting
of equipment.
choice
confident
which equipment
abandoned
camp
to logging
needed.
plane
float
largest
a very
to bridge
equipment
camp
restricts
we had more than was
fact
was
bridges
remote areas helicopters
in
team flew to we
fit
Alaska
necessary
from logging
Moving
float
of the
inspection
field
assignment.
was
drill
auger.
decayed
quickly
The
was
auger
wood.
or damaged
fre-quent
There are other problems associated
is
often rainy which
very
Waders and
protected.
equipment
The increment
forms were printed
inspection
used
must be weatherproof
Steel tapes were
augers were
on write-in-the-rain
The weather
Alaska.
inspection in
bridge
all
gear are a necessity.
rain
was required.
oiling
with
means that
also
oiled
or
but
used
All of the
often.
paper.
sub-tracted
On
bridges
was
drilled
over
40
A
was
core
Any decayed
wood.
decayed
was measured
diameter
stringer
abutment.
to each
adjacent
to locate
stringer
long the
feet
taken
at
or damaged
and each
stringer
each
end of the
wood
found was
cal-culations.
from the diameter
wood
The
was determined.
On
drilled.
A
20
bridges
pick
was used
Thus an
of that stringer.
average
feet
to
40
of
feet
diameters
effective
all
in
on the remaining
length only
stringers
diameter
effective
was used
selected
to check
of sound
the
in
were
stringers
surface
The
decay.
con-sistently
nota-tion
diameter
and soundness
Abutments
cores of these shortspan
were checked
exhibited
and decay.
for undermining
more decay
than
bridges
was measured
Notched
abutments which were not
was made on the inspection form whether
at
midspan.
abutment
or not abutment
logs
logs
A
notched.
were
notched.
de-cay
Whether
or not they
were cabled
was
recorded.
also
Or-ganisms
Several things became
thought
logs.
that
stringers
that
cause
In fact
than
be more
readily
after
the
decay were expected
bridges
stringers
apparent
with
with
dried
the
to
conversely
thrive
Stringers
stringers
11
was completed.
was
It
had greater resistance to decay.
bark remaining
bark removed.
and
inspection
field
with the bark removed
under the bark
consistently showed
with
attacking
the
less
surface
the bark removed
appear
with bark always
showed
a high
to
of saturation.
degree
that
a
number
High moisture
Low
we
This
8
content
to inhibit
annual
average
appears
temperature
12 years were
to
is
in
growth of decay-causing
the
organisms.
to what
but
factor
reason
good shape.
relatively
an influencing
also
to be the
was thought
content
moisture
high
of older bridges
extent
not determine.
could
Sta-bilizers
sta-bilized.
Another
to better
bridges
more
showed
individual
that
bridges
Curiously even
as
when
a unit
The rock
used
20-foot
bridge
loads
surface
a span
even
than
feet
was found to have
those
on
factor
bridge
a
of cover.
feet
were
that
log acted
stabilizer
on
deflection
distribution.
deciding
of cover
22
of 40 feet.
length
individual
less
better
was another
are
logs
4.
fig.
or longer seemed to exhibit
stabilizer
.log showed
produced
Stabilizer
logs.
stringers
which had no cables or
cabled
Three to four
to the
exceeding
categoty
this
bridges
bridges
a running
as
the
without a
However
stabilized
strength of a bridge.
One
those
loaded.
spans and
long
in
deflection
stringer
of stabilizer
the use
distribute
important on bridges
are particularly
Observation
concerned
finding
interesting
on some
used
This
the
in
relative
uncommon.
not
is
had
particular bridge
over-stressed
26
and was over
stringers
around 16
Under
feet.
60
feet
wide.
This
normal calculations
width of
to a roadway
tapered
would be greatly
mini-mum
rock-fill
with
We
felt
the
effective
the
that
the
cover
running
a
Failures were
The
few.
the
3 feet
in
some
failure
was much
The
less.
maximum.
of the
soil
to keep
5
Figure
show
any
deflection.
such a manner
in
that
may be forming
material
cover
material
a
to a
an excessive
illustrates
are most
common
from season
elevation
is
however
structures
was due to abutment
were caused
significantly
water
bridge
good design policy
is
suggested
common
failures
vary
in
the
it
of this type
failures
stream
is
However
did not
surface.
observed
most
Abutment
on the bridge
However
12 inches
bridge
this
the
was being distributed by the
deadload
load
soil bridge.
as
material.
these were
undermining.
of the
by improper design
on smaller waterways.
to season
the
of
waterway.
required
Flows on
this
an overnight
for instance
In
not uncommon.
relatively
Most
Area 42
Ketchikan
type
rise
of
of
inches
of
al-most
rain
fell
in
October
Observation
1974.
of stringer
In already
failures
was observed but individual
bridges
were not cabled
always
saturated
were a number of bridges
had
under the wheel
that
No
was uncommon.
stringers
failed
or had cables which
were located
terrain
were
lines
were composed
12
in
this
rain
complete
some
loose.
of traffic
of several
failure
bridges.
The
becomes
of any bridge
Typically
failed
on the
runoff.
these
stringers
bridge.
layers of logs
There
fig.
6.
1
F
G
fLL
yý
yy
Figure
1.
Log
stringer
bridge
r.
f
7
.m
y
F
s
ýYFr
Figure
2.
Staney
d
Creek Bridge
13
- 94
ft.
simple
span.
d
r
C
3xýx
y
i
r
yivs
YYV.y
Figure
3.
Short-span
log
stringer bridge.
PQQD.-or
Decking
Stabilizer log to
lashed
to
brow
exterior
Material
be
A.p.9
logs
a
ylov
stringers.
Use turnbuckles.
Stabilizer
12
in.
dia.
such
that
Notch
all
Log
min.
For
4.
over
35
ft.
in
SECTION
NEAR MIDSPAN
stringers bear.
Figure
spans
Stabilizer logs used
14
to
distribute
ý
load.
length.
L
ý
-LýiTLý
h
.f
ýýý2..
1
ir
ý
t4.
ý
1
ý
.
c
...
jM
x
..
i
yýYSit
.
S
G.
iý ýY
t1
t
0
ý.ý
s
e
Figure
Excessive
5.
blast-rock
fill
on
stringers.
ý
i
1
rY4.
0
d..
A.
.izYý
4Týt
Figure
6.
Multiple-layer
15
log
stringer bridge.
II
I
up-ward
In most cases
the
One
removed.
Over the years the road grade
layers.
about 10
The data
made on
by our inspection
relative
log stringer
was generated
on
bridge and rather than replace
original
the
over
bridge
this
of the
top
had apparently
bridge
However
original.
was composed
inspected
of three
changed
feet.
gained
the
for
guide
not
on the
failed
was constructed
bridge
was
bridge
original
had
a stringer
one stringer another
in
be used
will
strength of existing
bridges
was
bridges
Analysis has
ways.
A
for a signing program.
The need
initiated.
and procedures
areas
several
several
in
for additional
been
design
information
for inspecting log stringer
bridges
were developed.
Our
have
conclusion
relatively
is
that
log stringer
good design
bridges
southeast
life for
to
are simple
economical
construct
and
Alaska.
AUTHORS CORRECTION
From
Field
7
Notes Volume
Number
7
July
1975
12
P.
dou-bled
Gas vodas Design
The
of Gasvodas
circuitry
unit differed
previously been examined however
Power
consumption
50
enabled
feet.
the
permitted
A
timing
counter
use
was one-forth
of dry
circuit
to reject
cells
the
that
made
advantages
of
GCOs
lasted
events.
The
up to 60 days
16
the
risk
best unit and the
to insure count-accuracy
spurious
that
from that of any of the units that had
worth
taking.
range
had been added
reduction
in
power
under continuous
was
which
requirement
operation.
WASHINGTON OFFICE ENGINEERING NEWS
OPERATIONS
Harold
Strickland
L.
Assistant Director
FOREST SERVICE REMOTE SENSING MANAGEMENT COMMITTEE FSRSMCJ
the rapid
of remote sensing technology
evolution
and the need for
compri-ses
Recognizing
prudent
application
Staff established
FSRSMC
on June
The
now
active
in
Chief
C.
Nelson
Deputy
2.
NFS
M. R.
Howlett
R.
K.
PL
G.
S.
5.
Research
6.
AM
7.
H.
L.
As soon
as
possible
carrying
out
will
1.
methods
L.
the
charter
Continuous
area in the
Deputy
NFS
Chief and
Staff
support
FSRSMC
Washington
for the
Office
committee.
of
FIDM
Situation
to the
Analysis
FEMR
Administrative
Director
FSRSMC
Chairman
of Engineering
Director
Executive
following
Vice
Chairman
Management
Secretary
will
submit
Chief and Staff
a
detailed implementation plan
for approval.
As a
minimum
for
the
areas of responsibility
evaluation
for managing
for the
core group
M. Hughes Director
Lundberg
the
Director
Bergoffen
J.
for
Director
Smith
Strickland
its
cover
Sensing
executive
the
members are
T.
SPF
Service
Management Committee
remote sensing are providing
1.
4.
Forest
the
in
Remote
The
1975.
core group
executive
3.
plan
2
technology
Service
representatives from each
one or more
those
of such
a Forest
of the
remote sensing
need for and the
activities
17
in
the
development of
Forest
Service.
alternative
Coordination
2.
USDA
of
remote sensing
all
within
activities
the
Service and
Forest
coun-try.
devel-opment
with
other
agencies
Development
3.
first
session will be designed
of subsequent
sessions
at
Service
on the
and
state-of-the-art
and
staff
Two
locations.
sector.
throughout
personnel
WO
for the
field
private
sessions
training
Forest
for
and the
agencies
of
of a series
of remote sensing
applications
The
Federal
the
lead to the
will
major
or three
sessions
at
re-mote
with well-developed
universities
These
sessions
4.
facilities
are to be cooperative
be long enough
ventures
with
hands-on experience
to provide
executive
Providing
staff and programs
counseling
the
be considered.
will
and they
universities
shall
with materials and systems.
to the Chief and
service
Staff
on
sensing matters.
Any
you might have
suggestions
for action
by the
committee
be appreciated.
will
TECHNOLOGICAL IMPROVEMENTS
Heyward
Taylor
T.
Assistant Director
INTERACTIVE ROAD DESIGN SYSTEM
IRDS
al-though
In April
1974
a group of engineering
Center to discuss the
Computer
System compatible
economic
the
and equipment
the
feasibility
with
and computer
feasibility
of using
Univac
newly-acquired
constraints
personnel
a
need for the system had been recognized.
of the
road
and began to develop
approach
design
the
which they
specification
with
the
of the
termed Interactive
Road
Road
Collins
Design
of this concept
The group
availability
working
Fort
at
Prior to this both
1108.
introduction
prevented
met
conversational
upon
agreed
of the Univac
environment
the
1108
and system
IRDS.
re-sults
configuration
From
the
April until
first
phase
of the
of this test
RDS
June
system assigned to
data
storage
IRDS
1974
Regional
personnel
worked
their
respective
Regions.
In July preliminary
was done on the Medicine
were favorable
and
System
Design
retrieval
but
they
system.
pointed
RDS
18
Bow
out
personnel
to
develop
National
several
the
portion
of
testing of the
Forest.
weaknesses
met and agreed
The
in
the
to modify
the
system equipment
which was
of the
data.
timely
After
retrieval
the
Engineering
Computer
Center
on IRDS
was
additional
in
data
moved
Region
was recognized
It
to the
2 decided
data maintenance to put
Fort
that
that
Collins
development
three forests
on IRDS
system needed
the
known and were
these were
but
accommodate
to
storage
EDSG
September
design season.
features
the
RDS
for
Support Group
following
1975
operational
used
for proper
sufficient
for incorporation
The
Design
the
in
for the
production
RDS
being
developed
program.
completed IRDS
earth-work
land
that
managers reported
ample time
for
to contract
awards.
estimated
review
One
forest
of the
estimated
of between
reduction
volumes
the
and follow-up
$5000
project
projects output provided
design
in
$1500
savings of
and $10000
their
in
per project
prior
file offices
costs
travel
and an
reduced
in
costs.
favor-able.
IRDS
Presently
and
The
10.
has
been introduced
system was
personnel
field
comments from the
CONSULTATION
Charles
1 2 3 5 6 9
Regions
in
and adheres
by engineers
designed
consequently
specification
to
users
to field
strictly
have been consistently
field
AND STANDARDS
R.
Weller
Assistant Director
POSTER AND SMALL METAL SIGNS CATALOG
The
This
much
about Posters and Small Metal
talked
catalog
includes
all
of the posters
Signs
and small metal
catalog
signs
that
is
in
distribution.
are currently
available.
display short-term
Posters
people
messages
Poster
congregate.
along roads
messages
cover
in
campgrounds
a wide array
or wherever
of messages
Fire
including
card-board
Prevention
Messages.
Rules
of Use
However
managers should
are applicable in their
posters
removed
and Conduct
particular
are presentable
before
they
for
in
Developed
carefully
situation.
only
a
It
plan
should
few weeks
become faded wrinkled
19
Areas and Environmental
and
select
only posters
be remembered
after
or torn.
which they
that
that
should
be
permanent metal
Small
closing gates
and recreation
One problem
that
small metal
in
has
come up
Maryland
repeatedly
surveys
are available
from FPI
available
GSA
from
only
from Central Supply
only
and vinyl posters are
are available
signs
and
improper ordering of posters
the
is
posters
reflectorized
and small metal
Atlanta
land
regarding
messages
developments.
Non-reflectorized
signs.
Landover
with
are available
signs
Denver
in
in
Colorado.
Cen-tral
Non-reflectorized
metal
must be ordered
posters
on the Federal
signs
out
units
who have been
considerable
delay
Supply who
trying for months
it
is
often
to get
discovered
not stock
does
Many
address.
that
your orders
we have
times
a
Form AD-14 and
Standard
Please be sure that
Strip.
and sent to the proper
filled
on the
particular
are properly
heard
of
small metal
was ordered
it
small
ordering
sign.
improperly
After
from
them.
NEW PUBLICATIONS
pas-senger
con-taining
Aerial
March
Tramways
Ski Lifts
1967 publication.
This
tramways for Forest
associated
with
- EM
and Tows
publication
is
116 pp.
7320-1
primer
a
on the subject
Service personnel
who
are newly
The
text
is
these transport
systems.
Revision
illus.
of the
of aerial
assigned to activities
and nontechnical
general
Gov-ernment
of the
a description
used
terminology
manufacture
in
and
of tramways
types
installation
components
their
and operation
of aerial
it
contains
passenger
Re-vision
recommenda-tions
tramways
ski
lifts
Printing
The Smith
River
and tows.
For
Highway
20402.
D.C.
Office Washington
of Documents
by the Superintendent
sale
Visual Analysis Study
Available
- EM
in
7700-3
August 1975.
142 pp.
illus.
in-formation
and expansion of
of a visual
study
original
1973 publication.
system designed
analysis
about highway construction.
ranging
small scale
by the
D.C.
from broad-scale
evaluations
Superintendent
of existing
of
to
This
translate
The system
is
a complete
Documents
conditions
Government
20402.
20
presents
a
raw data into
interpretation of the
scenic
publication
along
package of
entire
study
Highway
Printing
visual
area to very
199.
For
Office Washington
sale
NEW OPTICAL SENSOR DEVELOPED
Heyward
T.
Charles
Taylor
Improvements
Technological
R.
Weller
and Standards
Consultation
success-ful
The
Forest
be detected
can
new equipment
This
Department
of an experimental
operation
beam
U.S.
Service
a companion
which
system through
a
the
pulsed
laser
of up to one mile.
for a distance
visually
today announced
of Agriculture
surveying
detector
to the
Forest
Services
Range
Laser
Un-like
mal-functions
is
Pole system for property
Both systems use
years.
range
beam
laser
pulsed
a
which has
location
line
in
been
of the
place
for the last
operation
in
standard
two
surveyors
pole.
The
sensor system can
electro-optical
the
error that
the
between
projected
it
is
operable
on the
zero-in
When
the
laser
beam
The
points.
the
error
but
the
has
electronically.
a slight margin
positive
for
sensor
electro-optical
cannot be detected
receiver provides
visual
beam
laser
bright daylight
in
system does not have.
visual
locating
in
of the
system
visual
the
until
precise
line
is
alignment
line.
connecting
sub-dued
opera-tion.
The new
receiver was
visual
California acting
who
observed
first
by the
the
Stans-Optic
such
pulsed
Division
as
late
over
our
by the Forest
developed
on information
through
evening
at
night
a
Army
Sacramento
from our Southern Region
by engineers
supplied
laser
night or
in
San Dimas
Service at
vision
Depot.
scope.
It
was fabricated
It
operable
is
This
morning.
only in
some
presents
eye-piece.
light
disadvantages
The
receiver
the
gathering
The
present
receiver
visual
visual
Range
attached
early
Pole system because
to a modified
transit acts
light magnifying it then
receiver was
much
transferring the
designed
originally
of the nighttime
Army
by the
as
television
a
image to the
to enhance
night
vision.
This
to
innovative
accomplish
lands.
There
and Puerto
patterns with
located
immense amount
are
by more than
of a million neighbors.
lands
National
apparatus
of surveying
187 million acres of National
Rico bounded
three-quarters
between
and sophisticated surveying
the
in
System
land
Forest
272000
lands
A
private ownership.
Forest
and marked
The
is
vital
required
to the
System land
miles of property
21
in
big percentage
Service
forest
46 States
lines
are often intermingled
adjoining
in
of the property
and adjoining lands have not
on the ground.
Forest
on government
complex
lines
been adequately
it
Many
of the
Many
miles of line and their
With conventional
lost.
each
controlling the
surveys
year
much
as
With the new
third the
to
complete
One
it
6 inches
per mile.
With the
laser
mile above
sender
the
is
transit
locked
where a stake
in
be done
the
is
marked
sighting
laser
beam was
in
12
or
line
surveys
million.
about a
years at
200 years would be needed
surveys.
equipment
laser
dense
the
beam
vertical
according
between
directly
how
than
old.
are located
lines
more than $100
a cost of
can
other point the
extended by the regular
level
at
job
line
one point a
at
is
or
then
ground
miles of property
methods more
sighting
terrain
At the
ground.
The
receiver.
the
from the new
how. rough the
no- matter
estimated
is
McGuire
R.
established
and property
corner
benefit
significant
now
conventional
Using
all
Chief John
corners
system
cost.
about 2000
150 years
as
been obliterated
have
corners
controlling property
methods
much
are as
lines
24 years would be required to bring the property
as
up to date between
property
forest.
operator
sees
to Forest
It
is
accurate
perhaps
the
line
and marking methods
high
through
within
as
a
the
lowered to
is
of sight.
to the
to
as
pulse
and the scope
on the projected
Service
a mile apart
points
pulsed
is
direction
exact
two
This
point
line
is
where
the
neces-sary
fired.
With conventional
to
before
methods
make many
the
in
with
sightings
true property
mountainous
can
line
surveying
be
or heavily forested terrain
instruments
it
is
and many calculations
established.
estab-lishment
Chief McGuire
is
neighboring
home
the
The
are more
the
importance of more rapid property
of land
increasing use
owners-ranging
development.
consequences
that
explained
and
its
dangers
severe
he
of trespass
by the Forest
resources
from timber harvesting
to
on both
condominium
sides
line
Service and
and summer
are increasing and the
said.
22
GPO 894-867