FUNCTION OF THE PONTON COUPLINGS
The ponton couplings are the connection points for locating and holding IRB bays
together in the construction of a bridge or raft. The upper couplings are designed to
secure the bay to another bay until the lower lock pins can be engaged. The lower
main coupling at each end of the inner ponton receives the lower lockpin. The lower
main coupling is designed as a connecting eye, is made of steel, and is bolted to the
inner ponton and a steel tie. The steel tie extends longitudinally the full length of
the inner ponton. In a bridge or raft configuration, the loads placed on the adjoining
bays are carried by the steel tie rather than the aluminum structure of the inner
ponton itself. The upper coupling is made of steel and utilizes steel receptacle
blocks bolted to the inner ponton. During bridging operations, the longitudinal
upper couplings, except for those on the ramp bay, are opened to allow the bays to
hinge at the lower main couplings. During rafting operations, the longitudinal
upper couplings are closed for adequate rigidity.
FUNCTION OF THE PUMP SYSTEM
The pump system provides the mechanical means to change the angle of the
entire ramp bay longitudinally, when connected to an interior bay, thereby raising
or lowering the height of the ramp end of the roadway to meet a given river bank
elevation. In operation, two manually operated pumps supply pressure to two
cylinders each connected to a yoke on the inner pontons. The cylinders act to push
the yokes out simultaneously at the bottom, and as the yokes are extended, the
IRB-R hinges upward against the weight of the adjoining IRB-I.
FUNCTION OF THE TRANSPORTER (HEMTT)
The transporter functions to load/unload, launch/retrieve, and transport the BAP
and bridge bays to and from launch sites. The transporter is a HEMTT equipped
with a load handling system (LHS). The LHS is powered by the HEMTT. The
HEMTT fluid system supplies pressure to the LHS by way of a PTO-driven pump
on the HEMTT transmission. Control valves within the fluid system direct the flow
of fluid to the LHS lift cylinders and winch motor. A cab-mounted control box and a
hand-held remote control unit (RCU) are used to electrically actuate solenoids on
the control valves for LHS operation.
FUNCTION OF THE CBT LOAD HANDLING SYSTEM (LHS)
The LHS is the lifting device for loading and unloading the BAP and supporting
the winch when lifting and loading bridge bays. Bays cannot be loaded on the LHS
without the BAP. The LHS is mounted on the HEMTT frame and contains a lifting
arm which is raised and lowered by four fluid cylinders.
FUNCTION OF THE BRIDGE ADAPTER PALLET (BAP)
The BAP is the base support for a bridge bay during movement. It contains a
detachable winch frame that locks to the LHS hook arm for bay launch and
retrieval operations. Operation of the winch is possible only from the RCU.
TM 5-5420-278-10
0005 00
0005 00-2
END OF WORK PACKAGE
