Launch Beam - TM-5-5420-279-230042

TM 5-5420-279-23

1-10-23 Launch Beam

The launch beam, when deployed, provides support for the bridging modules and

accommodates the forward and rear carriages during bridge construction. It comprises eight

beam modules which connect together to form the launch beam. Seven modules are transported

to the bridging site on a PLS flatrack carried on an M1076 PLS trailer and a forward launch beam

carried in the launch frame of the launcher vehicle.

The modules are of traditional web chord construction in aluminum alloy 232B and feature

identical top and bottom extrusions, which terminate with welded-in jaw arrangements. A series of

diaphragms to absorb torsional loads are built in along the length of the beam. The side webs

have stiffeners to prevent buckling and the top chord of each beam incorporates lifting points.

Fig 1.7 Launch Beam

The welded-in jaw arrangements at the top and bottom of each module end are identical

and multi-lugged. The forward jaws of each module are aligned to contact the jaw lugs of the

beam module already positioned in the launch frame and then pinned in position; upper jaws first

and then the lower jaws. The lower jaws being aligned by a mount resilient jaw guide system.

The launch beam connecting pins incorporate a flat on the head of the pin, which allows

insertion into the lugs in one position only. This allows insertion of the pin locking clips also in one

position only and prevents them causing damage to the rollers during beam deployment. The

forward launch beam module provides a frame mounting for the far bank support.

The launch beams incorporate safety rollers and stop blocks. The safety rollers raise the

launch beam stop on the launch frame during booming so that the stop block on the proceeding

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