JOINT FLEET MAINTENANCE MANUAL

APPENDIX D
COMFLTFORCOMINST 4790.3 REV A CH-1
MINIMUM POST SHAKEDOWN AVAILABILITY SEA TRIAL REQUIREMENTS
FOR A SUBMARINE DEEP DIVE
1. The following tests and evolutions will be carried out following the initial tightness dive and prior to the deep
dive:
a. Transmit initial tightness dive complete message. Charge air banks and battery if necessary. The ship
may be submerged while charging air banks provided the depth of the ship does not exceed other
guidelines in this instruction, or those of the flooding bill or ship's operating procedure.
b. If escort is required, detach the escort after initial tightness dive. The escort will then proceed to station
for the deep dive. Ensure that deep dive rendezvous time and location are clearly established before the
escort is released. The escort may be detached after completing all initial tightness dive events and
surfacing using EMBT blow from depths of 400 feet or deeper. The escort may be used for additional
testing on the transit. Transit depths shall not exceed initial tightness dive depths.
2. The following tests and evolutions will be carried out immediately prior to or during the deep dive:
a. Ensure the air banks are charged to within 200 psi of full pressure.
b. Line up Main Ballast Tank (MBT) system for normal operation.
c. Take sounding. Accurately fix ship's position within the specified dive area along with the maximum
water depth as given in reference (h). Transmit the commencing deep dive message.
d. Submerge to periscope depth and trim the ship.
e. Obtain stop trim. Take readings required to make a check of ballasting.
f. Trim ship to maintain neutral buoyancy (Note 1).
g. Line up propulsion plant for maximum reliability in accordance with ship's instructions.
h. Rig ship for deep submergence. All systems should be in maximum secure condition with unnecessary
sea systems isolated as prescribed in reference (i).
i. Station additional personnel throughout the ship to inspect for leaks as deemed necessary.
j. At depth specified in reference (i):
(1) Inspect for leaks.
(2) Adjust trim (Note 1).
I-6D-1