SECTION III: PRINCIPLES OF OPERATION
end connectors and wedges, guides, and guide caps. The guides ride between the dual wheels and through a trough in
the track drive sprocket hub to maintain track alinement.
1-20 FIXED FIRE EXTINGUISHER SYSTEM
The following callouts are found in Figure 1-12.
The M88A1 is equipped with a fixed, carbon dioxide, fire extinguisher system for smothering fires in the engine and
winch compartments. The system consists of eight 10-lb (4.5-kg) cylinders (1), a cylinder control valve (2), remote
control connectors (3), two dual-pull mechanisms (4), extinguisher lines, seven nozzles, two exterior
remote control pull handles (5) with cables, two
interior remote control pull handles (6) with cables,
and an engine shutoff switch (7) (to ensure the engine
2 Cylinder control valve
is turned off before the fixed fire extinguishers are
3 Re control connectors
4 Dual-pull mechanism
discharged). Each cylinder is equipped with a safety 5 Exterior remote control pull handles
valve that automatically discharges when pressure
6 Interior remote control pull handles
becomes excessive due to heat. The cylinders are
7 Engine shutoff switch
mounted in banks of four on each side of the cab
The engine shutoff switch (7) consists of a push button
switch assembly (electrically connected in series with
the engine fuel shutoff solenoid and the vehicle
batteries), which is depressed (open circuit) during
vehicle operation by an adjustable screw mounted on a
hinged metal shield held in position by a quick-release
pin. When it is necessary to discharge the fire
extinguisher system, the push button on the quick-
release pin is depressed, allowing the shield to pivot
downward, which releases the adjustable screw from
the push button on the switch assembly and activates
the fuel shutoff solenoid, shutting off the engine.
1-21 WINCHES, SPADE ASSEMBLY, AND HOISTING BOOM
The following callouts are found in Figure 1-13.
a. MAIN WINCH
The main winch (1) is mounted to the nosepiece of the vehicle beneath the crew compartment. It is gear-driven by a
hydraulic motor and is used for heavy-duty recovery operations. The winch is wound with 200 ft (61.0 m) of 1-1/4-in.
(31.8-mm) steel cable. The cable is equipped with a clevis on the free end for securing it to loads.
Figure 1-12. Fixed Fire Extinguisher System