3A1. General. A modern submarine contains, in addition to the mechanisms required to operate it on the surface, a multitude of operating machinery and tanks required to enable it to dive, surface, and proceed submerged. This fact makes it one of the most compact vessels afloat. Yet the submarine is designed and arranged along simple and logical lines, and in spite of the seeming confusion of valves, lines, and apparatus, everything in the submarine is situated to insure the maximum of speed and efficiency. (See FigureA-1.)

The modern fleet type submarine consists of a superstructure and a hull surrounded for the most part by various fuel and water ballast tanks. The pressure hull, designed to withstand the sea pressure, houses most of the ship's machinery and provides the living quarters for the officers and the crew. It is divided into eight watertight compartments, separated by pressure bulkheads provided with watertight pressure resistant doors. The ninth compartment, the conning tower, in the shape of a cylinder placed on its side, is located above the control room and connects with the control room through the access hatch.

The compartments, in turn, are divided by means of the platform deck into upper and lower sections, which contain the spaces housing the various equipment and providing the necessary facilities for the submarine's officers and crew.

3A2. Forward torpedo room. The foremost compartment in the submarine is the forward torpedo room (See Figure 3-1.), located between frames 16 and 35. The forward torpedo room contains six torpedo tubes in its forward bulkhead; torpedo racks on its port and starboard sides, immediately adjacent to the torpedo tubes for carrying

  spare torpedoes; torpedo loading hatch overhead; and torpedo handling equipment. Four of the torpedo tubes, Nos. 1, 2, 3 and 4, are above the platform deck, while tubes Nos. 5 and 6 are below the platform deck. The sonar gear, underwater log, and an access hatch to the escape trunk are also located in the forward torpedo room.

The following is a list of the more important equipment located in the forward torpedo room:

1.Hydraulic pump and ram for bow plane tilting
2.Hydraulic motor for windlass and capstan and bow plane rigging
3.Impulse charging manifolds (port and starboard)
4.Torpedo tube blow and vent manifold
5.Torpedo tube drain manifold
6.Torpedo gyro regulators
7.Blow and vent manifold for normal fuel oil tanks No. 1 and No. 2
8.Blow and vent manifold for No. 1 sanitary tank
9.Blow and vent manifold for fresh water tanks No. 1 and No. 2
10.Officers' head
11.Bunks and lockers for crew (usually at least 10 men)
12.High and low external compartment air salvage valves
13.Compartment air salvage (internal)
14.Oxygen flasks
15.Sound-powered telephones
16.Bow buoyancy vent operating gear
17.No. 1 main ballast tank vent operating gear

Photos of Forward Torpedo room.
Figure 3-1. Forward torpedo room.

Photo of Forward battery compartment
Figure 3-2. Forward battery compartment.

3A3. Forward battery compartment. (See Figure 3-2.) The forward torpedo room is separated from the forward battery compartment by a watertight bulkhead and door. The lower part of the forward battery compartment houses the 126 forward battery cells. The upper section of the compartment contains the officers' quarters, the chief petty officers' quarters, and the yeoman's office. The entire forward battery compartment is located between frames 35 and 47. The officers' quarters provide wardroom and staterooms for the ship's officers, sleeping accommodations for the chief petty officers, and officers' showers and pantry.

Also located in the forward battery compartment are:

1.Ventilation supply lines
2.Ventilation exhaust lines
3.Bulkhead flappers
4.Main ballast tanks No. 2A-2B vent operating gear
5.Battery blowers
6.External salvage air connections (one high and one low)
7.Compartment internal salvage air connections
8.Oxygen flask
9.Sound-powered telephones

3A4. Control room. (See Figures 3-3, 3-4, and 3-5.) Going aft, the compartment immediately adjoining the forward battery compartment is called the control room. It is located between frames 47 and 58 and is the main control center of the submarine. The control room contains:

Starboard side forward-aft:

1.Electric circuits and switchboard (IC switchboard)
2.High-pressure air manifold
3.225-pound air manifold
4.600-pound main ballast tanks blowing manifold
5.10-pound main ballast tanks blowing manifold
6.Auxiliary power switchboard
7.Main ballast tanks Nos. 2A and 2C

Port side forward-aft:

1.Gun access batch
2.Oil supply tank
3.Signal ejector
4.Hydraulic air-loading manifold
5.Negative tank inboard vent
6.Hydraulic manifold
7.Bow and stern plane diving station
8.Trim manifold
9.Main ballast tanks Nos. 2B and 2D emergency vents

Centerline forward-aft:

1.Steering stand
2.Master gyro
3.Pump room hatch
4.Periscope wells
5.Sound-powered telephones
6.Radar mast

In the overhead:

1.High and low external compartment air salvage
2.Internal compartment air salvage
3.Ventilation supply and exhaust lines
4.Bulkhead flappers
5.Oxygen flasks

In the pump room:

1.Hand and hydraulic operating gear for negative flood
2.High pressure air compressors
3.Low-pressure blower
4.Drain pump
5.Trim pump
6.Vacuum pump
7.IMO pumps
8.Hydraulic accumulator
9.Air-conditioning machines
10.Refrigeration machine
11.IC motor generators

Photo of Control room starboard side and radio room
Figure 3-3. Control room (starboard side) and radio room

Photos of Control Room
Figure 3-4. Control Room

Photos of Pump room
Figure 3-5. Pump Room

The after section of the control room is occupied by the radio room which houses the transmitting and receiving radio apparatus, and radio direction finder. The engine induction and ship's supply outboard valve operating gear is located in the radio room overhead.

Access to the radio room is from the control room, which is in turn is accessible from the officers' quarters passageway forward, crew's mess hall aft, and the conning tower access hatch overhead.

3A5. Conning tower. The compartment immediately above the control room is the conning tower. (See Figure 3-6.) It is the main navigation and firing control station for the submarine. The conning tower contains the periscopes and the periscope hoist equipment, the radio direction finder, the sonar equipment, the radar equipment, the torpedo data computer (TDC), the gyro repeater, the conning tower steering stand, and the various pressure gages and indicators.

The conning tower connects with the control room through a watertight hatch. This is designated as the lower conning tower hatch. The upper conning tower hatch provides access to the bridge from the conning tower. The conning tower also has a ventilation exhaust connection and its own air-conditioning coil. Since the conning tower is the commanding officer's battle station, all communication lines include the conning tower in their circuits.

3A6. After battery compartment. The compartment aft of the control room is the after battery compartment (See Figure 3-7.), located between frame 58 and frame 77. It houses the after battery with its 126 cells below the platform deck. The battery cells are connected to the exhaust system by ducts leading to the battery blowers. The forward end of the after battery space, below decks, also contains the cool and the refrigerating

  rooms and the ammunition magazine. Above the platform deck, the after battery compartment contains the crew's galley, mess hall, and the crew's sleeping quarters.

The more important equipment in the after battery compartment consists of emergency vents for safety tank, FBT No. 3 and No. 4; hand-operated flood valves for FBT No. 3 and No. 4; main vent operating gear for safety tanks, MBT No. 2C and 2D, FBT No. 3A and 3B, FBT No. 4A and 4B, and FBT No. 5A and 5B; the hydrogen-detecting apparatus; the blow and vent manifold for fuel ballast tanks No. 3A and 3B, 4A and 4B. The galley equipment, scuttlebutt, battery exhaust blowers, and the radio receiver for the crew are also located in the after battery compartment.

The after part of the after battery compartment contains the crew's bunks (usually 36) with individual lockers for each bunk and a medicine locker. Separated from it by a non-watertight bulkhead and a door are the crew's head, showers, washing machine, and lavatories.

The after battery compartment is provided with an external high and low compartment salvage air valve.

3A7. Forward engine room. The forward engine room (See Figure 3-8.) is located between frames 77 and 88, and houses No. 1 and No. 2 main engines. The main engines extend from below the platform deck into the engine room space, with No. 1 main engine on the starboard side and No. 2 main engine on the port side. The main generators, No. 1 and No. 2, are below decks aft of the main engines beneath the platform deck, and are directly connected to them.

The forward engine room houses the vapor compression distillers, fuel oil pump (standby), lubricating oil pump (standby), engine air inboard induction hull valve, and various main engine starting and stopping controls.


Photos of conning tower
Figure 3-6. Conning tower

Photos of After battery compartment and crew's quarters.
Figure 3-7. After battery compartment and crew's quarters.

Photos of Forward engine room.
Figure 3-8. Forward engine room

The forward engine room also contains the following:
1.High and low external compartment air salvage connection
2.Internal compartment air salvage connection
3.Hull ventilation supply valve
4.Supply blower
5.Exhaust blower
6.Bulkhead flappers
7.Oxygen flask
8.Sound-powered telephone
9.Fuel oil purifier
10.Lubricating oil purifier

3A8. After engine room. The after engine room (See Figure 3-9), located between frames 88 and 99, is similar in many respects to the forward engine room. It houses the No. 3 and No. 4 main engines and main generators.

In addition, the after engine room houses the auxiliary generator and the auxiliary diesel engine, both of which are located entirely below the platform deck.

The upper space of the after engine room houses the after engine air inboard induction hull valve, the high and low external compartment air salvage connection, the internal compartment air salvage valve, the lubricating oil and the fuel oil purifiers and the pumps. The compartment also contains:

1.Standby fuel oil pump
2.Standby lubricating oil pump
3.Air-conditioning unit
4.Hull supply lines (ventilation)
5.Access hatch
6.Oxygen flask
7.Sound-powered telephone
8.Bulkhead flappers

3A9. Maneuvering room. (See Figures 3-10

  and 3-11.) The upper section of the maneuvering room, frames 99 to 107), contains the maneuvering control stand, indicators, gages, lathe, crew's head, auxiliary switchboard, remote control for engine shutdown, oxygen flask, high and low external compartment air salvage, internal compartment air salvage, maneuvering room induction hull valve, hull supply lines, and bulkhead flappers.

The lower part of the maneuvering room is called the motor room and has the Nos. 1, 2, 3, and 4 main motors. The four main motors are directly connected with the two reduction gears. The main motors Nos. 1 and 3 are directly connected with the reduction gear No. 1, and the main motors Nos. 2 and 4 are directly connected with reduction gear No. 2. The reduction gears in turn are connected with the propeller shafts.

The circulating water pumps and the lubricating oil pumps are also located in the motor room.

3A10. After torpedo room. The aftermost compartment on the submarine is the after torpedo room (See Figure 3-12), located between frame 107 and 125. Unlike the forward torpedo room, it contains only four torpedo tubes in its after bulkhead. However, it also has the torpedo racks, torpedo handling equipment, and spare torpedoes.

The after torpedo room has one impulse charging manifold, torpedo tube blow and vent manifold, torpedo gyro regulators, and the torpedo tube firing indicator and controls. It also contains the escape and rescue hatch, the torpedo loading hatch overhead, the hydraulic steering rams and pump, the stern place tilting mechanism, the torpedo tube drain manifold, the crew's bunks and lockers, the ventilation supply line, the bulkhead flappers, the oxygen flasks, the emergency air connection for escape hatch, the high and low external air salvage connections, the internal compartment air salvage, and a sound-powered telephone.


Photos of After engine room.
Figure 3-9. After engine room

Photos of Maneuvering room above platform deck.
Figure 3-10. Maneuvering room above platform deck

Photos of Motor room.
Figure 3-11. Motor room

Photos of After torpedo room.
Figure 3-12. Maneuvering room above platform deck

3B1. General.The exterior view of the submarine presents a very low silhouette. This is due primarily to the fact that the submarine is designed to have a low center of gravity for stability and is normally two-thirds submerged as she rides on the surface.

The exterior hull of the submarine has a cylindrical shape, which gradually tapers forward of frame 35 and aft of frame 107, becoming the bow of the superstructure and the rounded stern. (See FigureA-2.)

The superstructure deck, called the main deck, extends virtually from the tip of the bow to frame 124 near the stern. The deck is generally level. Beginning about the midship section it rises gradually in the direction of the bow, to a height of approximately 12 feet above the water line. The freeboard of the after end of the main deck is about 4 feet.

The main deck is attached to the exterior hull by means of the framing and rounded sides. Limber holes in the sides allow sea water to enter all the hollow spaces in the superstructure and the deck when diving, and drain off when the submarine is surfacing.

The midship section of the main deck is occupied by the conning tower, which is surmounted by the bridge deck, with periscope shears, periscopes, radio compass loop, and radar antenna.

The after section of the bridge deck contains the ship's pelorus, one 20-mm anti-aircraft

  gun and after ammunition ready locker, while the forward section of the bridge may have either a 20-mm or a 40-mm anti-aircraft gun, depending upon the particular ship. Two ammunition ready lockers are located in the lower part of the conning tower superstructure, one forward and one aft. The gun access trunk is located forward and one aft. The gun access trunk is located forward of the conning tower and is provided with a hatch opening onto the main deck.

The forward section of the deck contains the 5"/25 wet type gun, galley access hatch, after engine room access hatch, after torpedo loading hatch, after rescue and escape hatch, marker buoy, and capstan.

The bow is equipped with six torpedo tube shutters, three on the port and three on the starboard side, and the bow diving planes.

The underside of the hull contains ballast tank flooding ports and underwater sound heads.

The after end of the ship, on the underside, is equipped with the four stern torpedo tubes, two on the port and two on the starboard side, port and starboard propeller struts, propellers, stern diving planes, and the rudder.


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