b. Loading/Unloading Scissored Bridge to/from a Lowbed Semitrailer
(M12 or M172A1 - CONT
When securing the bridge to the trailer, DO NOT pass the steel chains through the
aluminum pin holes of the center hinges or connectors. If this is done, damage to the
aluminum pin holes will result, rendering the bridge inoperable.
(2) Unloading. Unloading the bridge from the lowbed semitrailer is essentially the reverse
procedure of loading.
Prior to releasing and removing the tiedown chains from the bridge/trailer, the launcher
should be engaged to the bridge on the trailer to prevent the bridge from slipping or
shifting its position.
Use extreme care when releasing the binder handles to avoid backlash.
The launcher operator should wear protective headgear or close the hatch when
recovering the bridge onto the carrier to prevent injury from falling rocks and debris
as the bridge is brought back into the travel position on the launcher.
(a) Move the vehicle forward, lower and position the tongue for engaging the launching
diaphragm of the bridge.
(b) Ensure that the pintles of the tongue are fully seated into the launching diaphragm.
The assistance of a crewman is needed for directing the engagement of the pintles into the
launching diaphragm, and making the two hydraulic line connections on top of the
(c) With the launcher connected to the bridge on the trailer, remove the tiedowns and chain the
tie-rod ends of the bridge.
(d) Proceed to retrieve (lift) the bridge off the trailer, by working both launcher cylinder levers
(#l, the overhead cylinder, and #2, the tongue cylinder) in unison.
2-88 Change 2