EQUIPMENT DESCRIPTION, AND THEORY OF OPERATION
RAPIDLY EMPLACED BRIDGE (REB)
THEORY OF OPERATION AND EQUIPMENT DATA
This section explains how components of the REB and CBT work. Functional descriptions of the CBT,
pallet, and bridge components and their operation are covered in the following paragraphs.
FUNCTION OF THE COMMON BRIDGE TRANSPORTER (CBT)
The transporter functions to load/unload and transport the pallet with or without the bridge to and from
launch sites, and can also provide emergency back-up hydraulic and electric power to the pallet for bridge
launch/retrieval operations. The CBT is a HEMTT equipped with a Load Handling System (LHS). The LHS
hydraulic system is powered by way of a PTO-driven pump on the CBT transmission. Control valves within
the LHS hydraulic system direct the flow of hydraulic oil to the LHS lift cylinders. A cab-mounted control
box and a hand-held Remote Control Unit (RCU) are used to operate the solenoid-actuated control valves
necessary for LHS operation. To power the pallet using CBT, the LHS hydraulic hoses are disconnected
from the CBT hydraulic pump, and the pallet's hydraulic hoses are then connected to the CBT hydraulic
pump by way of quick-disconnects. The CBT's slave power cable is connected to NATO slave receptacles on
the pallet and CBT.
FUNCTION OF THE CBT LOAD HANDLING SYSTEM (LHS)
The CBT's LHS is utilized to load and carry the REB pallet (with or without bridge) in the same way it
is used for the M1 Flat Rack, M15 Bridge Adapter Pallet (BAP), and M14 Improved Boat Cradle (IBC). The
LHS is permanently mounted on the HEMTT frame and contains a lifting arm that is hydraulically raised
and lowered by way of the CBT hydraulic and electrical systems. Only the pallet can be carried on the LHS;
the bridge or bridge halves alone are not designed to interface with the LHS.
FUNCTION OF THE PALLET
The Pallet is the launching mechanism and transport frame for the bridge. The Pallet's launcher
mechanism couples the two bridge halves together and emplaces them to the ground. Launch and retrieval
of the bridge is performed while the pallet is on the CBT only. The pallet has two supporting cylinders that
assist in supporting the weight of the bridge on the CBT during launch and retrieval operations. The bridge
is intended to be transported on the pallet by the CBT, although once coupled and emplaced, the bridge can
be lifted, transported, and emplaced by helicopter. The pallet is designed to be transported on the CBT or
the Palletized Load System Trailer (PLST). The pallet is transloaded from the CBT to the PLST using the
CBT LHS. The pallet cab be maneuvered on the ground by its own support wheels and steering system
which is provided primarily for loading onto an aircraft. The pallet has a self-contained hydraulic and
electrical system powered by a small diesel engine called the Launch Power Unit (LPU).
FUNCTION OF THE PALLET LAUNCHER MECHANISM
The launcher mechanism is part of the pallet, and is made up of five major components that work
together to couple, extend, and emplace the bridge as follows:
The launch boom functions to hold the bridge by its launch beam during launch and retrieval. The
launch boom contains a number of upper and lower support rollers, a pin wheel drive unit, and a
brake, which together support and propel the bridge as it is extended and emplaced.