OPTIONS WHEN USING MULTIPLE BRIDGES
MIXED
CAPACITY SYSTEMS
Bridges are sized for an individual rated load. Runways are sized for the combined
weight of all loads, so they use a heavier track series than the bridges.
Advantages:
- No
“dead” coverage areas (areas with no bridge coverage). Each bridge can
travel the length of the system.
- Limited
“dead” coverage areas between bridges, so bridges can be used side-by-side.
- Bridges
weigh less, making them easier to move.
Disadvantage:
- Use
larger sized runways, so they may cost more than intermediate stops
or bridge buffer systems.
BRIDGE
BUFFER SYSTEMS
Bridges are sized for an individual rated load. Runways are sized for
the heaviest individual load, so the runways use the same track series
as the largest bridge. Bridges are physically separated by wheeled, movable
bridge buffers.
Advantage:
- Usually
cost less than mixed capacity systems because they typically use smaller
sized runways.
Disadvantage:
- Buffers
take up space, creating a moving “dead” space between bridges.
Note: With two bridges, the dead space equals
half the distance of the support centers (L1 from the dimensional charts).
When a third bridge is added, the dead space occupied by the additional
bridge buffers equals the distance of the support centers. Special support
steel may be required.
SYSTEMS
WITH INTERMEDIATE STOPS
Bridges are sized for an individual rated load. Runways are sized for
the heaviest individual load, so the runways are same size as largest
bridge. Bridges are physically separated by internal stops or bumpers.
Extra hangers may be required to eliminate overload.
Advantages:
- Use
smaller runways; therefore typically cost less than mixed capacity systems.
- Fewer
potential “dead” spots in the system.
Disadvantages:
- Each
bridge on the system can travel only a portion of the length of the
system.
-
May cost more to install since they require extra supports to eliminate
an overload situation.
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