The Forest Service manages an extensive road and trail transportation
system. The road system has more than 7,500 bridges. These bridges are inspected
primarily by Forest Service engineers, although some are done by State engineers
or by private engineers through contracts. Forest Service standards and qualifications
for bridge inspectors require formal training. They are described in Forest
Service Manual 7736 and comply with 23
CFR part 650.307. The formal training is available through the National
Highway Institute.
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Sheeps Crossing trail
bridge, Sierra NF, R-5. This
bridge, which was designed by the R-5 bridge group, won the
American
Institute of Steel Construction (AISC) design award in
1984. It was the first cable-stayed bridge built in the
state of California. |
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The trail system has several
thousand bridges and boardwalks. Most are native log and
treated timber structures, but there are also conventional
steel and concrete bridges. In recent years we have also
successfully installed fiberglass and composite (fiber-reinforced
plastic) trail bridges. Many are simple span bridges, but
others are arch, suspension, or cable-stayed structures.
As a major builder and owner of trail bridges, we have
developed bridge design standards that apply to all types
of trails. The regional bridge engineers are familiar with
these standards and must be contacted for preparation of
all bridge design proposals. Standards for trail bridge
inspectors and inspections are currently being developed.
For more information, go to http://www.fs.fed.us/r3/measures/trails/Trails.html
Design authority for the forest to proceed with local
design of all bridges, including acquisition of prefabricated
structures, must be requested from the Regional Office
(FSM 7722.04). The reason for this level of review and
approval is to provide safe structures for the public and
our employees by maintaining consistent design standards.
For additional information about bridge design or training
visit the American Society
of Civil Engineers. For information about designing
with timber, visit the Guide
to Wood Design Information, which also contains a list
of Timber
Associations.
Ropeways
Ropeways are ski lifts, tramways, and tows. They are most
commonly found operating in the winter at ski resorts.
Half of all ski areas in the United States are located
on National Forests and operated under special use permits.
Each year, more ski areas are open year round to serve
sightseers, mountain bikers, and hikers. Some tramways
are built primarily as tourist attractions not associated
with ski resorts.
Forest Service engineers are responsible for monitoring the safe operation
of the ropeways, under agreements with the ski area operators. Forest Service
engineers cooperate with State tram boards, private engineering firms, and
insurance companies to perform regular equipment inspections.
Forest Service engineers have been active participants
in the establishing and developing of the American National
Standards Institute safety standard for ropeways, ANSI
B-77.1, which is applied to virtually every ropeway in
the US.
Other info — Forest Service internal use
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