USS ALBACORE - "Forerunner of the Future" - AGSS 569 - Pioneering Research Vessel
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Start - On Path Outside Visitor's Center Main Entry Door

Visitor Center

Welcome to Albacore Park. The Albacore was a one-of-a-kind submarine built, home ported and maintained here in Portsmouth by the skilled craftsmen of the Portsmouth Naval Shipyard across the way in Kittery, Maine. The first submarine named Albacore was lost in the Pacific during World War II.

Streamlined hull

Classified by the Navy as an Auxiliary General Submarine, Albacore was the first modern submarine to have the rounded, teardrop shaped hull. Her test or maximum operating depth was 600 feet and her conventional lead acid battery gave her a maximum submerged speed of 25 knots or almost 30 miles per hour. Albacore was built strictly as an experimental submarine - she had no torpedo tubes and carried only pistols and rifles for her security watch. She was small - at 205 feet long, she was 2/3rds the length of a World War 2 Fleet Boat; and fast - with her special silver zinc battery, Albacore could outrun a contemporary nuclear submarine until her battery was exhausted. Albacore was highly maneuverable. Due to the steep angles the boat sometimes took, subway car type straps could be found throughout the boat for people to hang onto when the boat was performing hydrobatics - or underwater acrobatics. In addition to being used as a high speed submarine target, Albacore was the platform for trying out new submarine propulsion and control systems, tactics and operational concepts.

Launched in August of 1953, Albacore was placed in commission in December of that same year. Albacore remained in active service until September of 1972 when she was decommissioned and moved to the Philadelphia Naval Shipyard. She remained in Philadelphia until 1984 when she was towed to Portsmouth and later moved to her current location in 1985.

In 1989, Albacore was designated a National Historic Landmark due to her contributions to submarine design. In 2000, she was further honored with the designations of being a Historic Mechanical Engineering Landmark for her many unique systems and as a Historic Welded Structure for her hull. In May of 2005, Albacore was inducted into the Submarine Hall of Fame located in Norfolk, Virginia due to her contributions to submarine engineering and tactics.

The pathway to your right leads to our Submarine Memorial Garden which honors the sacrifices made by our submariners.

Dolphin carving

Included in the Garden is a sculpture of a dolphin, the symbol adopted by the submarine force. Straight ahead is the entrance to our Visitor's Center and museum where you may view pictures, ship models and artifacts from the Albacore, purchase tickets to tour the submarine and purchase submarine related items to remind you of your visit.

Station One - Outside Museum near Propeller Field

Propeller field

In the area in front of you are some of the propellers used by Albacore and other submarines. Albacore was the first modern submarine to have only one propeller. Originally built to use the single large propeller you see, Albacore was later outfitted with two counter rotating propellers as part of an experiment to provide greater propulsion efficiency. One of the three smaller propellers was a spare for Albacore while the other two are from the USS Jack (SSN 605) the only other US submarine to have a counter rotating propeller propulsion system.

Under the leadership of Admiral Charles Momsen, Albacore was conceived to inaugurate a radical change in submarine design. Experience in World War II had shown that speed, endurance and maneuverability were key requirements for submarines. As a result, Albacore's hull was designed with underwater speed as the prime requirement. Scale models of the hull were tested in tow tanks and wind tunnels to determine the optimum hull design. (With this streamlined hull, Albacore was able to set submerged speed records in 1965 with a conventional lead-acid battery and again in 1966 with a higher capacity silver-zinc battery.) Albacore was built with a newly developed high-strength steel hull. Along with these two innovations, Albacore was to serve as a test vessel for the newest designs in submarine technology. Throughout her career, she tested many innovative concepts. As a result, the U.S. Navy was able to refine these designs before incorporating them into the fleet. Albacore truly lived up to her motto: "Praenuntius Futuri" or "Forerunner of the Future".

Please proceed to the next station located at the ship's stern.

Station Two - Outside at Stern of Albacore

X-stern and counter-rotating propellers

As you walk down the length of Albacore toward the entrance at the bow, notice some of her unique external features. She has two counter-rotating propellers which provided greater propulsion efficiency. The rudder and dive planes are in an X-configuration as opposed to the conventional cross arrangement. The X-stern and two propellers were respectively parts of the third and fourth phases of Albacore's external control system development and gave the boat great maneuverability submerged and on the surface. Albacore was designed to go through four different phases or configurations of control surfaces and propeller arrangements. The original arrangement of the after control surfaces had them located behind a single propeller in the conventional cruciform or cross configuration with a small set of bow planes located forward on the hull. The second configuration changed the position of the after controls to be forward of the propeller and removed the bow planes entirely.

All submarines are designed with positive buoyancy on the surface. To submerge, valves on top of the four ballast tanks that surround Albacore's hull were opened to let the air escape through the top of the tanks and allow sea water to rush in through flood grates at the bottom of the tanks. As the tanks filled with water, the boat lost its positive buoyancy and submerged. Once the boat was fully submerged, the valves were shut and the tanks were ready for surfacing. To surface, high pressure air was directed into the top of the tanks and the expanding compressed air forced water out through the flood grates in the tank bottoms. Positive buoyancy was regained and the boat rose to the surface.

Please proceed forward to the next station.

Station Three - Outside at the end of the aft exit Ramp

Dive brakes area

Starting just behind the sail, but since welded shut, was a series of ten large doors that ringed the hull. These doors could be popped opened like dive brakes on an airplane to rapidly slow the boat when submerged in case there was a casualty to the control system. Although they made the boat vibrate heavily, the dive brakes worked as intended. However, they had a tendency to pop open on their own at high speeds due to the sucking action of the water flowing over the doors. Although a good idea, the dive brake mechanism was removed and the doors were welded shut.

Before the dive brakes were installed, a parachute used to decelerate a jet bomber after landing was borrowed from nearby Pease Air Force base. The idea was that the parachute, when released from its housing near the top of the sail, would open and create a large drag force to slow the submarine and tilt the bow upward. However, the parachute material wasn't strong enough and tore away.

Sail with dorsal rudder

Looking up at the after end of the vertical superstructure or "sail", you will see a second rudder. This "dorsal" rudder was used to counter the tendency of the boat to perform a snap or sharp roll when turning at high speeds with the first rudder and stern planes configuration. There was concern that a sharp enough roll would create a control problem wherein the rudder and stern planes would reverse their functions and an uncontrollable dive below test depth would ensue. Testing proved this not to be true and the dorsal rudder was deactivated. A similar rudder/stern planes situation was predicted with the x-stern and the dorsal rudder was reactivated. However, a vernier system was installed which, when activated, limited the amount of rudder (and planes) movement and proved to be an effective way to control the amount of roll.

Just aft of the numeral 5 on the sail are several slots cut into the sail. These slots allowed air to be taken in to the sail and then pass through the main induction valve and into the boat. Through these slots passed air used by the ship's diesel engines when the ship was running on the surface. Some of this incoming air was circulated throughout the boat by the ship's ventilation system.

Please proceed forward to the next station outside the bow entry ramp.

Station Four - Outside at the Ramp to Forward Entry

At the forward end at the very top of the sail, notice the flat windshield and clamshell like doors. There is a small platform up there where the Officer of the Deck or OOD and one lookout stood their watch when the boat was underway on the surface.

Housing for anchor

Just before you enter the forward access door to the boat, notice the large hinged door up and to your right. Behind this door is the ship's anchor. And look back along the length of the boat and notice how few objects protrude from the hull to disturb the smooth flow of water. Every effort was made to streamline the hull so as to maximize the boat's hydrodynamic design.

Ballast tank

As you enter, notice that there is a thin outer hull and a thicker, inner hull. The outer hull provided Albacore with its streamlined shape while the inner thicker or pressure hull had the strength to resist sea pressure at deep depths. The space here between the two hulls is a part of one of the two forward ballast tanks.

As you enter the boat, be sure to watch your head.

Station Five - Bow Compartment by Escape Trunk

Base of forward escape trunk

As you enter this space, directly in front of you is the forward escape trunk. It was the main entry point for anyone coming on board. As the name implies, it was to be used in case the boat was disabled and unable to reach the surface. A submarine rescue chamber or mini-sub would seat itself on the main deck above the upper hatch and the sub's crew would climb up to it through this trunk. If there was no rescue vessel or chamber available, three crew members at a time could escape into the water from this chamber and, using inflatable life vests, free rise to the surface. The museum has a life vest, known as a Steinke Hood, on display.


Crews berthing port and starboard sides

The bow compartment, the first of five watertight compartments separated by heavy doors, was used principally as enlisted crew's quarters. There were 26 bunks in this space - one of two main berthing areas for the enlisted men. If you were assigned one of the upper bunks, you had to be somewhat of a gymnast to get in and out of it. You can see that some bunks shared space with large valves and other pieces of equipment. The right hand photo shows where 3 additional bunks were located before the bow access doorway that you came in through was cut in the hull.

One of the ship's two high pressure air compressors is located in the space below the berthing area. This vital piece of machinery provided the compressed air, stored in large flasks, that was used to expel water from the ballast tanks when it was time for the boat to surface.

Because Albacore was intended to be a research vessel, there were few creature comfort or homey type items. To begin with, there were just enough bunks for the assigned 50 man crew. And, as you can see, there was very limited storage space for any personal gear. If their bunk was built with a pan, a crew member could gain access to his clothes and toiletries stored in the flat space underneath the mattress by lifting up the pan. The green covers over the mattresses serve several purposes. Firstly, they are fire resistant. A submariner's greatest fear is a fire when submerged. These 'flash covers' protect the mattress from becoming part of a fire. Secondly, the flash cover keeps the ever present moisture in a submarine's atmosphere from being absorbed by the mattress and helps to protect the bedding.

When special projects or tests were undertaken at sea, it was not unusual to have instrumentation spread out over several of the bunks thus creating a shortage of sleeping spaces. It was then that "hot bunking" came into being. Hot bunking is where three people would share two bunks - one person on watch and two sleeping. When the watch ended, one of the two sleepers was up for the next watch and the off-going watch stander climbed into the just vacated "hot bunk". Compounding the bunking situation were the extra personnel now on board to run the test instrumentation. Fortunately, few of the special projects required the boat to be at sea for any extended period of time so the hot bunking was of relatively short duration.

Watertight door to forward battery

Please proceed aft to the next compartment, the Forward Battery. Watch your head as you go through the watertight door.

Station Six - Forward Battery by Pantry

Wardroom pantry

On your right as you enter is a small pantry which held the dishes and silverware for the officers mess. The pantry contained a small warming oven and refrigerator for keeping food warm/cold until it was time to be served. Food was prepared aft in the galley and brought forward and served out of this area.

Commanding officer's stateroom

Across from the Pantry on your left is the Commanding Officer's stateroom. A Commanding Officer usually had a room to himself, but because of the small number of berthing spaces, there is a second bunk which was for the Executive Officer. There is under bed storage, a Pullman sink, a desk with drawers for clothing and an upright closet for hanging clothes. Note the instruments mounted at the forward end of the top bunk. They are there so the Captain could tell at a glance the ship's course and speed. There is also a sound powered telephone which allowed the Captain to reach any space in the ship. By simply dialing in the space he wanted to reach and turning the crank on the side of the box, he would be connected to that space.

Officers' stateroom

The next area aft on your left is the three-man officers' stateroom. The officers shared an upright closet, a desk and each had one drawer in the wardrobe unit. A fold down panel on the front of the unit became a shelf for writing. A Pullman type sink completes the amenities.

Captain's chair in wardroom

Forward end of wardroom

Across from the stateroom is the Wardroom. This is where the officers ate their meals, held meetings and in general conducted the ship's business. Beside the Captain's chair you can see one of the hand cranked telephone boxes and above it instruments that displayed ship's course and speed. At the forward end of the wardroom were lockers containing table and bed linens.

Wardroom settee rigged as a bunk

With a nominal complement of five officers, each officer had his own bunk. However, there were two additional bunks that could be made up in the wardroom when additional officers or senior scientists were on board. The back of the settee in the wardroom could be raised up and supported from the overhead to form one bunk while the settee seat itself was made up as the second bunk. A major drawback to sleeping in the wardroom, aside from the constant use of the space, was that you had to be up and out for every meal.

Station Six A - Aft Bulkhead of Passage to Ship's Office

Ship's office

Continuing aft on your right, the small space behind the wardroom was the Ship's Office. It was here that the ship's yeoman, or enlisted administrative assistant, maintained the ships records and files. Note that he didn't have a computer to work on, just on old fashion typewriter. And there was very limited space to store any supplies or files.

Hatch to forward battery space

The hatch or access plate in the deck outside the ship's office/wardroom passage is the entry to the battery compartment below. In this lower space were 250 battery cells that weighed about 1000 pounds each. This, and a second battery located under the Crew's Mess, provided the energy for lights, heat, air conditioning, cooking, and was the power source for all shipboard equipment in addition to turning the main motors that drove the ship through the water when submerged. The batteries were charged by electricity generated by running the two diesel engines located aft in the Machinery space.

During Albacore's third phase conversion to the X-stern, a special high capacity, silver zinc battery was installed. It was this special battery that gave Albacore the power to become the fastest submarine in the mid '60s.

Goat Locker

The space aft of the Ship's Office is the Chief Petty Officer's bunk room, better known as the "Goat Locker". Three bunks, a Pullman sink and small vertical lockers round out the amenities for these senior petty officers.

Station Seven - Forward Battery across from Radio Room

Officer's head

On your right as you proceed aft are two small closet like spaces. The first is the Officer's Shower - about the size of a phone booth. Because fresh water was a scarce commodity at sea, a once-a-week shower was the norm, whether you needed it or not. The second small space is the Officer's Head or toilet. A tank, known as a sanitary tank, located below the deck holds the shower water and refuse material from the toilet until the tank was emptied by pressurizing it with air and blowing the contents into the sea.

Radio shack

On your left just before you enter the next compartment is the ship's Radio Room or communications center. Equipment in this space gave the boat the ability to talk directly to shore stations and ships and aircraft it might be operating with. The Radiomen operated the hydraulics for raising and lowering Albacore's two radio masts.

Watertight door to control room

Please proceed aft to the Control Room, the next compartment. Watch your head as you go through the watertight door.

Station Eight - Control Room Forward by Navigation Center

Access trunk to bridge

As you enter the Control Room, immediately on your right is a door that opens to a narrow trunk that leads to the tiny open bridge atop the forward end of the sail where the Officer of the Deck and lookout stood their watches when on the surface.

Control room starboard side

Across from the bridge access door is the ship's navigation center where the Quartermaster of the Watch was stationed. The ship's quartermasters were responsible for maintaining and projecting the ship's path of travel, referred to as the ship's track, both when surfaced and submerged. The squarish table in the center of this space was used by the navigation team for laying out their charts and plotting the ships position. Under the table was the auxiliary gyro compass. Mounted on the bulkhead aft of the table is the fathometer, a device that measures the distance from the bottom of the ship's hull to the ocean bottom. This was an important navigation tool especially when leaving or entering port. The access hatch to the pump room is located in front of the IC switchboard. This space is a second auxiliary machinery space which contains the trim pump and a second high pressure air compressor.

IC switchboard

Outboard of the table is an array of switches on panels which make up the Interior Communications or IC network. These switches connect or isolate such systems as the sound powered telephones, compass repeaters, depth and speed indicators. The hatch to the second auxiliary machinery space containing a second high pressure air compressor and the trim/drain pump is located in front of the switchboard.

Ship's announcing and alarm panel

Mounted on the bulkhead forward of the Quartermaster's table is the control panel for the ships announcing systems and alarms.

Aft of the table was where the Messenger of the Watch was stationed. He ran errands for the watch standers which included calling the next watch, carrying verbal messages and reporting routine occurrences to the Commanding Officer.


In the center of the control room on the raised platform is the ship's periscope and it is here that the Conning Officer, usually the Captain or the Executive Officer, stood his watch. Unlike today's sophisticated periscopes with radar, radio, TV and infrared capabilities, Albacore's periscope contained a only a basic set of optics.

Chicken switch

Albacore was built with a number of redundant systems. In particular, the hydraulic systems were state of the art and complex. For example, in addition to the normal and emergency systems for the steering and diving planes, there was a separate set of hydraulics that, in an emergency, would allow the Conning Officer to over-ride and take control of the stern planes. Mounted above and behind the Conning Officer's station was a red colored Emergency Ship Control handle, commonly referred to as the Chicken Switch. If the Conning Officer was not satisfied with either the response of the planesman or the actions of the diving planes, he could take control and move them himself. The whole boat shook when the chicken switch was used.

Control room port side

To the left of the raised platform is the ship control area. The two seats were occupied by the Diving Officer (the inboard or nearest seat) and the Helmsman (outboard seat). The two shared the positioning of the x-stern control surfaces. The Helmsman was responsible for using the rudder function to steer the ordered course. The Diving Officer, using the diving plane function, was responsible for reaching and maintaining depth. The inboard (Diving Officer) set of controls could be electrically connected to control both the diving planes and rudder. Using the buttons on top of the control wheel, the Diving Officer also controlled the dorsal rudder located on the aft end of the sail. The row of red lights directly in front of the Diving Officer indicated the position of the dorsal rudder.

Notice the three colored buttons on the panel in front of the Diving Officer. The green button sounded the Diving Alarm. Two blasts of this alarm alerted everyone that the boat was going to submerge. Three blasts from this same alarm was the signal for surfacing the boat. The yellow alarm button was that of the General Alarm. This alarm alerted everyone to proceed to their General Quarters or Battle stations. The red button sounded the Collision Alarm which caused the heavy watertight doors to be shut and dogged tight and the ventilation system valves between compartments to be shut. This provided the maximum amount of watertight integrity in case a collision produced a break in the pressure hull.

Trim manifold

The Diving Officer was responsible for reaching and maintaining the ordered depth and for the "trim" of the boat. The boat was balanced or "trimmed" by adding or removing seawater from special 'trim' tanks located forward, midships and aft inside the pressure hull . For safety reasons, most submarines adjusted their trim such that they were slightly positively buoyant so that if they lost propulsion, the boat would slowly rise to the surface. Positive buoyancy usually required that water be pumped out of the midships auxiliary tanks after the boat was properly trimmed fore and aft. For ease of remaining on depth, the angle of the boat was adjusted downward by shifting water from the after to forward trim tank. Albacore usually maintained a one degree down bubble or angle to counteract the upward force of positive buoyancy. The Diving Officer gave orders to the Trim Manifold Operator who, through a series of valves and pumps, moved water in and out to sea and between tanks.

Christmas tree panel

Standing directly behind these seats was the Chief of the Watch. At his station was the Christmas Tree, a panel of red and green lights that indicated the condition of all the openings in the ship's hull that could cause flooding of the boat. A red circle indicated that a valve or hatch was open and a straight green light meant that it was shut. Before the boat was submerged, the Chief of the Watch would call out "Straight Board" so that the Conning Officer would know that all hull openings were shut and it was safe to dive.

The Chief of the Watch functioned as the Ballast Control Panel or BCP Operator, Trim Manifold Operator and Air Manifold Operator. Upon command from the Conning Officer to submerge the ship, the BCP operator positioned electric switches, located on the bottom half of the Christmas Tree panel, that opened valves to let air out of the four ballast tanks that surround Albacore's hull. Once submerged and functioning as the Trim Manifold operator, he shifted water, at the direction of the Diving Officer, in and out of the internal tanks to balance the boat. Also as BCP operator, he positioned switches to admit high pressure air into the ballast tanks when it was time to surface the submarine.

High-pressure air manifold

Acting as the Air Manifold operator, the Chief of the Watch stood ready to direct high pressure air into Negative and Safety tanks when directed.

Station Nine - Outside Sonar Room

Sonar consoles

As you move aft to the next section of the compartment located behind the Air Manifold you will find the Sonar Room. When submerged below periscope depth, the Conning Officer relied upon Sonar (Sound Navigation and Ranging) to serve as the eyes and ears of the ship. Two large consoles sit against the after bulkhead in Sonar. Albacore had two types of sonar mounted in her bow. One was passive or listen where the operator listened for sounds created by other ships, sea creatures, or the weather. Passive sonar only gave us a direction to a noise. If the contact was a ship, the operator could, by listening, determine characteristics such as how many propellers it had, how many blades on each propeller, how fast the propellers were turning and could estimate the type of vessel - merchant, fishing boat, warship, etc. The other, active sonar, required that we project a sound wave into the water and then listen for a returning echo. Active Sonar gave us bearing and range information. All sound contacts were logged and, if so designated by the Conning Officer, were tracked to determine whether or not they posed a threat of collision to Albacore.

Radar console

LORAN console

Forward of the sonar consoles is the ship's radar unit. When on the surface, it was used for navigation and detecting ships. When submerged, it could be used at periscope depth to search for nearby surface contacts when the antenna was raised above the surface on its retractable mast.

Master gyro compass

Opposite the Sonar Room on the deck is the master gyro compass and mounted on a bulkhead to the right is the Loran or Long Range Navigation unit. Functioning something like today’s satellite navigation system, Loran used signals from two or more know radio station sites to provide lines of position which the Quartermaster's plotted on special Loran charts to determine the ship's location.

Watertight door to after battery

Please proceed aft to the After Battery, the next compartment. Watch your head as you go through the watertight door.

Station Ten - After Battery by Galley/Scullery

Ship's galley

Immediately on your right as you entered is the ship's galley where all the food was prepared. Electric ovens, a deep fat fryer and a grill top were the only cooking facilities. From this galley, the ship's cooks prepared breakfast, lunch and dinner for the 55 officers and crew. In addition, a mid afternoon meal known as "soup down" of hot soup and sandwiches was served to all hands. "Mid rats" or midnight rations were served at 11:15 pm for the oncoming and off going watch standers. Also from this small galley, the ship's baker daily prepared fresh rolls, bread, pies, cakes and other pastries during the midnight to 4 am mid-watch.


Opposite the galley is the scullery where all the pots, pans, silverware, glassware and dishes were washed. The cooks were assisted by junior members of the crew referred as "mess cooks" in preparing, serving and cleaning up after each meal. The length of time one spent as a mess cook was usually 90 days.

Crew's mess

Down from the scullery area are three tables which constitute the mess deck or crews eating area. The mess deck was used as the site for all hands meetings and briefings, the place where the evening movie was shown and was the site for letter writing, card playing, a place to study for advancement examinations or where you could get a cup of coffee and relax for a few minutes.


Entrance to Hogan's Alley, and Hogan's Alley outboard looking aft

Opposite the mess decks was the entrance to the second of the crew's berthing areas known as Hogan's Alley. This area has 21 bunks for a total of 47 bunks between here and the bow compartment for the 50 enlisted men. (Remember the three bunks in the Goat Locker?)

Under the berthing and mess deck areas is a second battery compartment identical to that of the forward battery. If you didn't see it on your way in, there is a typical submarine battery cell located in the Visitor's Center.

Station Eleven - Aft end of After Battery in the vicinity of Crews Washroom


Crew's washroom and crew's head

At the after end of this compartment are the crew's washroom and toilet facilities to serve the 50 man enlisted crew. The toilets were flushed using sea water and drained into a second sanitary tank located under the deck. Because fresh water was costly in electricity to make at sea, fresh water usage was pretty much limited to about a gallon per man per day. A partial sink full of water was used to take a "bird bath". This consisted of brushing teeth, shaving, washing hands, face and whatever parts of the body needed washing. Due to sanitation requirements, only the cooks, baker and mess cooks were allowed to exceed the stringent water limitations. A weekly shower was taken if there was sufficient fresh water available.

Under the deck at the very aft end of the compartment are refrigerated spaces consisting of a chill room, a freezer and also a dry store room. When the ship was to be at sea for a prolonged period of time, canned and dry goods were stored down here and in lockers throughout the ship because there is never enough storage space for food on a submarine. Although never done on Albacore because of her relatively short periods at sea, it was not unusual for a boat going to sea for a long time to have cases of canned goods on the deck until space became available in the designated food lockers.

Watertight door to machinery compartment

Please proceed aft to the Machinery Compartment. Watch your head as you go through the watertight door.

Station Twelve - Machinery Space Under After Escape Trunk

Starboard engine room

Just inside the door on either side as you entered this aft-most compartment are two sound isolated spaces for the two main diesel engines. Manufactured by General Motors, these two high speed engines powered generators that produced the electricity to drive the main motors, charge the two high capacity main storage batteries and provided service power for lights, hot water, cooking and other housekeeping functions. Turning at a constant speed of 1500 RPM or twice the speed of earlier submarine diesels, these light weight aluminum engines had a history of frequent breakdowns. Albacore's two engines were the last ones of this type in active service. These engines, installed in an entire class of six submarines, were removed and replaced because of their unreliability. Those 24 dismantled engines and their repair parts were warehoused and used to keep Albacore's engines operational. One of the considerations for retiring Albacore was the cost to the Navy of either buying and installing new engines or starting up a long dormant production line to make additional repair parts since she had nearly used up all the parts taken from the other submarines.

After escape trunk

Above your head in between the two engine spaces is the after escape trunk. This trunk served the same purpose and functioned the same way as the trunk in the Bow Compartment.

Cubicle starboard side

Cubicle port side

Located just aft of the escape trunk is an area known as "Maneuvering" and at its center is the propulsion cubicle. The cubicle was the watch station of the main power electricians and it was here that electricity from the main generators (when running on the surface) or from the battery (when submerged) was applied to the main motors in response to the Conning Officer's speed orders.

Distilling unit control panel

Aft on the port side is where the two 300 gallon per day fresh water distilling units are located. These units took in sea water, boiled it and condensed the steam to make fresh water. Fresh water was stored in several tanks throughout the boat and was used for maintaining the main batteries, cooking and washing in that priority.

Station Thirteen - Machinery Space beside Main Motors

Main motors

On your left as you continue aft are the two main propulsion motors. Albacore was originally built with one motor, one propeller shaft and one propeller. As part of the Phase Four conversion package, this compartment was cut open and extended in length to accommodate a second main motor which was placed aft of the original motor. Each motor can produce 75 hundred horse power. The original propeller shaft connected to the forward motor was replaced by a smaller diameter shaft that fit inside the second, hollow shaft attached to the after motor. The motors were wired such that they always turned in opposite directions. When you walk past the stern on your way back to the museum, notice that the propeller blades are pitched in opposing directions so that they both provide thrust in the same direction even though they are turning in opposite directions.

Hydraulic pumps and MG sets

As you continue aft, you can see a maze of pipes and various pieces of auxiliary machinery such as lubricating oil and hydraulic oil pumps and accumulators or pressurized storage flasks. The lube oil pumps supplied oil to main motor and propeller shaft bearings to keep them moving freely and to prevent overheating. The hydraulic pumps kept pressure up in systems that operated the periscope, steering and diving planes, main air induction and engine room air supply valves, and the vent valves on the ballast tanks.

Station Fourteen - Machinery Space Aft near bridge over propeller shafts

After bulkhead starboard side

This picture shows the propeller shaft in the right hand side as it penetrates the pressure hull through the aft bulkhead of the machinery compartment. In the lower left side is the end of one of the hydraulic rams that position the control surfaces on the x-stern. The yellow box at the top of the picture is a battery powered emergency light that would come on if normal lighting power was lost. The orange colored box contains flashlights for emergency use.

For almost 19 years, Albacore served the Navy as an experimental vessel. Prior to Albacore, the fastest a submarine could go underwater was about 12 knots or about 13 miles per hour. In 1966, Albacore set a submerged speed record of 35 knots or just over 40 miles per hour. One of her last experiments was an attempt to make her even faster. Dubbed the Slippery Water project by some, its intent was to reduce the friction of the water flowing over Albacore's hull reducing the drag force and thus make the boat go faster. While the test results indicated about a 10 percent speed increase, the relatively small gain in speed was outweighed by the short duration of the system's effectiveness and the complex mechanical installation required.

In summary, Albacore was an undersea laboratory that demonstrated the use of several types of towed sonar devices, tested four different propulsion and control surface arrangements, evaluated several combined instrumentation panel displays, used sound quieting techniques for rotating machinery, introduced aviation type controls, evaluated a more effective ballast tank blow system, and introduced the fiberglass sonar dome as a replacement for the standard steel dome.

Notable among devices and systems tried but not universally adopted for use on later U.S. submarines were: dive brakes, the dorsal rudder, slippery water, counter-rotating propellers and the x-stern. While some foreign built submarines have adopted the x-stern, only the USS Jack, a nuclear powered submarine, was built with counter-rotating propellers.

Bridge over propeller shafts

Exit from machinery compartment

This completes your tour. To exit, please step up and over the propeller shafts and pass out through the door on the other side. Should you have any questions about Albacore, please inquire at the Visitor's Center. And thank you for visiting the historic ship Albacore.