JOINT FLEET MAINTENANCE MANUAL

APPENDIX F
LISTING OF TESTS TO BE
PERFORMED PRIOR TO, DURING AND
FOLLOWING FIRST DIVE TO TEST DEPTH
I-4F-1
COMFLTFORCOMINST 4790.3 REV A CH-1
1. The following tests and evolutions, as summarized in Table 1 of this appendix, will be carried out following the
initial tightness dive and prior to the deep dive:
a. Six hours of Independent Ship Exercise for crew training. (see Note 1).
b. 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 procedures.
c. Operate IFF and ESM equipment. If possible use aircraft. (see Note 2).
2. The following tests and evolutions, as summarized in Table 1 of this appendix, will be carried out immediately
prior to or during the first deep dive. Per Volume V of this manual, a second deep dive must be performed to
complete valve cycling and operation of systems not required for normal safe operation of the ship, i.e., torpedo
tubes, Trash Disposal Unit (TDU), hovering, plumbing. (see Note 3).
a. Ensure that air banks are charged to within 200 psi of full pressure.
b. Ensure all MBT blow systems are fully operational and in a normal line up configuration.
c. Take sounding. Maximum water depth is given in reference (p). Accurately fix the ship's position
within the specified dive area (reference (p)).
d. Conduct a dive to periscope depth. Obtain speed trim, if practical, at periscope depth. If sea state
requires deeper submergence, proceed slowly to (150 feet for SSN 688 Class submarines), (155 feet for
SSN 774 Class submarines), (160 feet for SSN 21 and SSBN/SSGN 726 Class submarines) to obtain
speed trim. (see Note 4).
e. Obtain stop trim. Take readings and water samples required to make a check of ballasting. Stop trim
should be conducted at the most desirable time during the trials.
f. Trim ship to maintain neutral buoyancy. (see Note 5).
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 the maximum secure condition with
unnecessary sea systems isolated. (see Note 6).
i. Station personnel throughout the ship to inspect for leaks.
j. At depths specified in reference (i):
(1) Inspect for leaks.
(2) Adjust trim. (see Note 5).