NOTE
When using the M51 dump truck model or
the M51A2 dump truck model as a dump
truck, racks, seats, bows, and covers must
be removed and stored off the vehicle.
Section XXXVII. MAINTENANCE OF EXPANSIBLE
VAN BODY--M291A1, M291A1C, M291A1D
M291A2, M291A2C AND M291A2D
2-246. General
telephone entrance jack and auxiliary power cable
entrance port are located on the left rear panel near
a. Van Body. Expansible van trucks M291A2
the bottom. The pioneer tool bracket and power
and M291A2C have a 17-foot van body mounted
cable entrance receptacle are located on the right
on an M63A2D chassis with auxiliary sills to raise
rear panel. A bonnet, extending from the front
the floor above the wheels. When fully expanded, a
panel of the van, houses two heating units and the
weathertight enclosure 7 feet high, and 16X17 feet
air conditioning unit. The electrical system, in-
in area is formed. Leveling jacks are provided at
c l u d e s a 24-volt dc circuit for vehicular light
each corner to stabilize and level the expanded
operation and
100-volt
and
208-volt, 3-phase
body. The van is sealed to prevent the entrance of
circuits for auxiliary equipment operation.
water and the escape of light in both the expanded
Vehicular clearance and blackout lights are located
a n d retracted positions. T h e M 2 9 1 A 1 D a n d
on the bonnet face and the van rear panel.
M291A2D trucks have a tailgate which can be
b . E x p a n d i n g M e c h a n i s m s . Refer to TM 9-
operated by an electric motor or vehicle driven
2320-211-10 for a description of the expanding
hydraulic system. All facilities including lighting,
mechanism.
heating, air conditioning, and blackout protection
c. Electrical Systems.
may be used in both the expanded and retracted
(1) G e n e r a l . The van electrical system in-
p o s i t i o n s . The M291A1C and M291A2C differ
cludes three basic electrical circuits for the
from the M291A1, M291A1D, M291A2 and
operation of its auxiliary equipment and vehicle
M291A2D, in that they have no windows. In the
lights.
All circuits incorporate appropriately
M291A1, M291A2, and M291A1D, and
designed overload protection and control facilities.
M 291A2D four windows with brush guards, insect
These are described under specific headings in this
screens, and sliding blackout panels are located in
paragraph. The circuits include:
each side panel to admit daylight to the van interior
(a) The 24-volt dc system, powered by the
when it is in the expanded position. Two entrance
vehicle batteries. This system is used only for the
doors, set into the side panels, toward the rear,
operation of the van body clearance and blackout
permit access to the van when it is in the expanded
lights. The lights are mounted on the four top
position. Two entrance doors in the van rear panel
outside corners of the van body. Connection to the
permit access to the van when it is in both the
vehicle electrical system is made by means of tee
expanded and retracted positions. Two stationary
connectors inserted into the vehicle rear light circuit
windows a r e l o c a t e d i n t h e r e a r d o o r s . T w o
at the lower left-hand corner of the van body (fig. 2-
lightweight aluminum ladders, stowed on the rear
230).
doors, facilitate access to the van floor level. A
