THE MARK 6 MOD. 1 PISTOL

PARTS MK. 6

MARK 6 AND MARK 6 MOD. 1

4. THE MK 6 AND MK 6 MOD. 1 PISTOLS are the hydrostatically-operated firing mecha-nisms used in these depth charge. Each pistols consists essentially of housing for the operating parts.

(a) A flange with which the pistol is secured in a depth charge case.

(b) A bellows, spring, and setting device for determining the depth at which the pis-tol will fire.

(c) A firing plunger assembly for firing the detonator.

HOW THEY WORK

The principal difference between the Mk 6 and the Mk 6 Mod. 1 pistols is an added devi-ce in the latter design which increases its maximum operating range to 600 feet.

5. When the depth charge is DROPPED FROM A RELEASE TRACK, the knob on the inlet valve cover on the pistol is broken off by a wioing plate on the track. When the charge is THROWN FROM A PROJECTOR the plain cover is removed by hand immediately before the projector is fired.

REMOVE SAFETY COVER BY HAND

6. As the charge sinks, water enters into the space inside the flange, bellows and bell-ows extension through the inlet valve. Pressure in this space forces the piston to move inward, expanding the bellows and compressing the firing spring. Motion of the piston stem brings the spring-engaging collar against the depth-setting spring, the point at which this occurs being determined by the piston of the adjusting bushing. Further in-ward motion of the piston takes place only as sufficient hydrostatic pressure is applied to compress the depth-setting spring between the spring-engaging collar and the inner end of the adjusting bushing. (When the pistol is set to fire at 30 feet, the pistol fire before the collar comes against the depth-setting spring. In this case, the entire resistance to motion of the piston is provided by the bellows, the firing spring and release plunger spring.)

7. As the piston moves inward it comes against the stem of the release plunger, forcing it inward and compressing the release plunger spring. When the recessed portion of the plunger comes opposite the locking balls in the firing plunger, these balls slip clear of the guide tube bushing and into the plunger recess. This frees the firing plunger from the guide tube bushing, which previously prevented it from moving toward the detonator. The firing spring then snaps the firing plunger and firing point against the detonator, causing it to fire.