DEPTH CHARGE UPKEEP ROUTINE FOR SHIPS

8. The following routine is recommended for the depth charge components noted when carried in release tracks, roller loaders, projectors or in stowage racks on decks of ships:

(a) DAILY ROUTINE FOR PISTOLS in ready condition and safe setting lock not attached.

1. Rotate index pointer clockwise from 30 foot mark to SAFE. Mark 6 and Mark 6 Mod. 1 pistols.

2. Turn index pointer counter clockwise from SAFE back to depth setting prescribed by Commanding Officer. Mark 6 and Mark 6 Mod. 1 pistols.

3. Remove safety cover and rotate index pointer of deep firing mechansim clockwise from "0-300" to "600". Mark 6 Mod. 1 pistol.

4. Turn index pointer of deep firing mechanism counter clockwise from 600 back to depth setting prescribed by Commanding Officer and replace safety cover. Make sure cover is screwed on tightly.

5. Examine safety covers. If any are defective in slightest respect, replace them. Make sure that covers are screwed on tightly. Mark 6 and Mark 6 Mod. 1 pistol.

WEEKLY ROUTINE FOR PISTOLS

(b) WEEKLY ROUTINE FOR PISTOLS in release tracks, roller loaders, arbors on projectors and stowage racks on deck, with safe setting lock attached:

1. Apply a few drops of light oil (#2110) on surface between index pointer and dial plate and around index pointer plunger. Rotate index pointer counter-clockwise from safe to 30 foot mark. Safe setting lock will be broken by this operation. Mark 6 and Mark 6 Mod. 1 pistol.

2. Turn index pointer clockwise back to SAFE. Install safe setting lock. Mark 6 and Mark 6 Mod. 1 pistols.

3. Remove safety cover and rotate index pointer of deep firing mechanism counter-clock-wise from "500" to "0-300". Mark 6 and Mark 6 Mod. 1 pistol.

4. Turn index pointer of deep firing mechanism clockwise from "0-300" back to "500" and replace safety cover. Make sure cover is screwed on tightly.

5. Examine safety covers. If any are defective replace them. Make sure that covers are screwed on tightly. Mark 6 and Mark 6 Mod. 1 pistol.

CAUTION: Do not attempt to rotate index pointer clockwise from SAFE to 30 foot mark or couterclockwise from 30 foot mark to SAFE. This may shear off index pointer stop pin. Mark 6 and Mark 6 Mod. 1 pistol.

(c) DAILY ROUTINE FOR BOOSTER EXTENDER MECHANISM in release tracks, roller loaders, arbors on projectors and stowage racks on deck:

1. Remove safety fork and note that spindle moves in approximately ¼ inch when the fork is pulled off. Mark 6 and Mark 6 Mod. 1 extenders.

2. Attach extender testing tool to extender spindle by placing recess, in end of tool, over the outboard end of spindle. Mark 6 and Mark 6 Mod. 1 extenders.

3. Using a medium pressure, work extender spindle in and out 10 times. Spindle travel must not exceed ¾ inch. Any further inward travel of spindle places booster enve-lope over the detonator and is dangerous. If spindle does not operate with reasonable freedom the booster extender should be removed from the depth charge and turned in for overhaul. The foregoing applies to both the Mark 6 and Mark 6 Mod. 1 booster extender mechanisms. If spindle sticks in seal on Mark 6 Mod. 1 booster exten-der when fork is removed back off on gland screw about ¼ turn with gland wrench. The function of the gland seal is to prevent moisture entering the booster exten-der hydrostatic chamber when the safety fork is in place on the spindle. Excessive slacking of the packing gland will permit water to leak along the spindle into the boos-ter extender chamber, with resultant corrosion and, at times, freezing around internal operating parts. Make sure that the testing tool is properly centered on the spindle that the gland seal will not be damaged when the edge of the tool passes through is as the spindle is pus-hed in.

4. Remove the extender testing tool.

5. Replace the safety fork. Bent or otherwise deformed safety forks must be replaced.

INTERCHANGEABILITY OF PARTS

9. To simplify assembly and use of these depth charges, all of the components except that cases are designed to be interchangeable. Thus a Mk 6 or a Ml 6 Mod. 1 pistol may be used with either a Mk 6 or a Mk 6 Mod. 1 booster-extender in either of the two cases, Mk 6 or Mk 7. Also Mark 6, Mark 6 Mod. 1 and Mark 6 Mod. 2 boosters may be used inter-changeably with pistols and booster-externders.

10. The Mk 7 Mod. 1 depth charge pistol may also be used (without a booster-extender) in depth charge cases listed above. However, it is not intended that this shall be done under normal conditions. A description of, and instructions for using, the Mk 7 Mod. 1 pistol, are contained in O.P. No. 866, (First Revision).