Snorkel in the US Navy - 1945 onwards

APPENDIX E - Fleet Submarine Snorkel Operating Procedure

Made available by Bob Emery of the Submariners Association of Canada West

FLEET SUBMARINE SNORKEL PIPING
SNORKEL INDUCTION (BLUE) SNORKEL EXHAUST (RED)

The order for secure snorkelling given by either the Commanding Officer or Conning Officer, depending upon the circumstances. The submarine's transition from a normal submerged routine to that of snorkelling was accomplished by the regular watch section. Snorkelling could be conducted with a maximum of two engines and, to preserve watertight integrity, normally carried out in one engine room.

EVOLUTION ON PREPARING TO SNORKEL

The order was relayed on the 1MC by the helmsman. i.e. 'Prepare to Snorkel, Two Main Engines Propulsion Charge.'

MANOEUVRING ROOM

Acknowledged on the 7MC. 'Prepare to Snorkel, Two Main Engines Propulsion Charge, Manoeuvring Aye.'

Signalled the Engine Priority to the Snorkelling Engine Room by either the engine room with the lowest hours or, if there were prior snorkels during the dived time, by utilising the coldest engines.

CONTROL ROOM

Raised the Snorkel Induction & Exhaust Masts.

Energized the Snorkel Control Circuits.

Drained the Snorkel Induction Mast to Negative Tank.

Placed control of the Main Snorkel Exhaust Valve (Able Valve) to the Snorkelling Engine Room.

AFTER BATTERY COMPARTMENT

Placed the Snorkel Induction Valve Operating Gear into Power.

Placed the Main Snorkel Exhaust Valve Operating Gear into Power.

SNORKELLING ENGINE ROOM

Lined up the engine room & engines for snorkel operation.

Placed the Engine Room Snorkel Exhaust Valve (Baker or Charlie) operating gear in Power.

EVOLUTION ON COMMENCING TO SNORKEL

At the order 'Commence Snorkelling' on the 1MC the Snorkel Induction Valve was opened from the Snorkel Hydraulic Manifold in the control room on orders from the Diving Officer.

Upon the Snorkel Induction Valve being opened the Snorkelling Engine Room watch keepers opened their Engine Air Induction Hull Valve. The Snorkelling Engine Room Throttleman then commenced rolling one engine with starting air whilst the Oiler opened the approx. 33 1/3 turns hand cranked Inboard Exhaust Valve.

At engine start the Throttleman opened his Engine Room Snorkel Exhaust Valve (Baker or Charlie), shut his engine exhaust dump (exhaust dumped into the engine room bilge during engine roll and initial start) and, upon the engine building sufficient exhaust back pressure to blow the Snorkel Exhaust Mast dry, opened the Main Snorkel Exhaust Valve (Able Valve).

When rigging for snorkelling, the Induction Mast was drained to negative tank to maintain the submarine's trim, amounting to approximately 8,000 pounds. In addition, when the Exhaust Mast was blown dry, the Diving Officer flooded 3,000 pounds of water from sea to negative tank to compensate for the water blown from the exhaust mast, for a total of approximately 11,000 pounds.

SECURE SNORKELLING

When the order 'Secure Snorkelling' was passed on the 1MC, or terminated by any of the Snorkel Electrical or Engine Safety Circuits, immediately & simultaneously the engines were stopped, all Exhaust Valves and Snorkel Induction Valves were shut, and the Snorkel Masts lowered and housed. When the masts were lowered they flooded from sea, thus making the submarine heavier by approximately 11,000 pounds. This extra weight is immediately compensated for by the rapid blowing of 11,000 pounds of sea water from negative tank thus maintaining the trim of the submarine.

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Comment by torres1944 on 2009-10-15 08:19:11
Excellent article! Thank the author for post it!