TM 9-2350-230-12, C11
Section 3-2. 152MM GUN-LAUNCHER
breech cavity when gun returns to battery and contacts
3-3.
Firing Procedure
the in-battery limit switch. A delay of 1.7 seconds before
The following table and illustrations provide
the breech opens provides time required for the
152MM gun-launcher conventional ammunition and
scavenging blast. The pressure gage indicates pressure
missile firing procedure.
in the system, in psi and number of rounds remaining
NOTE. Before operation, the crew must be
without further compressor operation.
familiar with the location and operation of all controls
e. Operation of the system is explained in
and services are covered in table 4-1.
3-3.1.
Deleted.
High Voltage Power Supply for
3-3.2.
Closed Breech Scavenging System
Conventional Mode Firing
a. M551 vehicles equipped with M81El gun/
A high voltage power supply provides a -120 volt pulse
launcher incorporate a closed breech compressed air
when firing the gun-launcher in conventional mode to
scavenging system. The system is used with both
eliminate the possibility of a misfire due to firing probe or
missile and conventional ammunition to scavenge
ammunition contamination. When the FIRE CONTROL
breech and gun tube of debris and gases.
selector is in CONV position, the + 28 volt vehicle power
b. The system consists of a four-stage air
to the firing probe is interrupted and the -120 volt power
compressor, two air cylinders, pressure gage, pressure
supply is energized. When the firing trigger is squeezed
regulator, on-off switch, solenoid discharge valve with
the 120 volt electrical pulse is sent to the firing probe.
manual discharge lever, and attaching hoses and fittings.
c. Compressor operation is automatically
3-3. 4. Ammunition Detent Identification
controlled by a pressure control switch which energizes
a. The ammunition detent assembly which is
the compressor motor when pressure in the system falls
referred to as "early design" is Type I detent assembly;
below 2800 (+ 100) pot, and de-energizes compressor
the "late design" is Type H detent assembly.
motor when pressure reaches 3100 (+100) pi. An
b. The Type m detent assembly is identified in
electrical interlock prevents operation of the compressor
one or all of the following manners:
when selector control is in missile mode, to avoid
(1) The designation "Type II" stamped on
possible voltage drop in the vehicle electrical system
face of detent housing cover.
during launching and tracing.
(2) Type m detent shaft has a smaller
d. Air (regulated to 630 psi regardless of
diameter (1/4-inch) than Type I and II detent shafts (3/8-
system pressure) is discharged into the closed
inch).
(3) Decal
positioned
above
detent
assembly stating "TYPE 3 AMMUNITION DETENT
INSTALLED".
3-4
