USS Albacore -- A Revolution by Design

By Mark W. McKellar [Format modifications and HTML markup by Andrew Toppan]


	It is difficult, looking at the U.S.S. Albacore from today's 
perspective, to fully comprehend the revolution she started in submarine 
design.
	Built as a test bed for the U.S. Navy, the Albacore featured a 
tear-drop shaped hull, new diving controls, a dorsal rudder and a new 
high-yield steel for her pressure hull. In addition, the Navy, at one time 
or another, experimented with speed brakes, contra-rotating screws, a 
drag chute, camouflage paint and three different arrangements of stern 
control surfaces.
	That she looks much like the attack subs easing in and out of nearby
Portsmouth Harbor is hardly surprising, considering how many of the concepts 
she tested have been incorporated into today's state-of-the-art subs.
	The Albacore occupies a unique place in submarine development 
bridging the era between World War II's submersibles to the atomic powered 
undersea craft of today.

Concept
 
	The submarines of World War II were effectively surface vessels with
submersible capabilities. They nearly always operated on the surface -
dipping under only to hide or attack. They were designed for speed and
stability on the surface.  When submerged, they operated at slow speeds for 
relatively short periods of time. Battery life was the primary 
restriction in extended underwater operations.
	ASW advances during the war had broken the back of Germany's U-boat
service. After 1943, U-boats were vulnerable to detection and attack
whenever surfaced.  To counter this, a new boat - type XXI - was developed. 
This type became operational in 1945 but it was too late for Germany. The 
type XXI boats were the first true submarines and were, in large measure, 
the basis for the next generation of Allied submarines.
	After the war the Undersea Warfare Committee of the National Science
Foundation issued a set of recommendations recognizing that submerged speed
and endurance were critical in war-making and survivability.  The NSF
recommendations called for a feasibility study of a submarine with a fully
rounded hull, a single propeller located along the axis, and a pressure
hull constructed with a new, stronger steel called HY-80.
	The NSF report ignited debate within Navy circles over a variety of 
issues such as the merits of twin propellers vs. singles, and the sacrifice 
of surface stability for undersea speed. The result of the recommendations 
and ensuing debate was the U.S.S. Albacore.

Phase I
	Construction was approved in 1950 and in March 1952 her keel was laid 
at the Portsmouth Naval Shipyard in Kittery, Maine. She was launched just 
over a year later, on Aug. 1,1953.  Cornelius Ryan, writing in Colliers, 
described her "weird, whale-like hull." Her shape - smooth, rounded into 
a tear drop, with a small stream-lined sail ,was vastly different from 
active duty boats in 1953. She was shorter and broader abeam than 
conventional submarines.
	Her designers had made every effort to streamline the hull - going 
as far as testing the shape in a wind tunnel. To that end, her capstans, 
cleats and bullnoses, antenna and periscope were housed in recesses when 
not in use.  Since she was an experimental boat, no weapons were ever 
fitted to the Albacore.
	In the first phase of testing, the after control surfaces were 
suspended behind the single screw by large arms.  She was fitted with bow 
planes and a small dorsal rudder mounted on the rear portion of the sail.
The dorsal rudder was included to prevent the boat from excessive heeling
during high-speed maneuvering.
	During her initial trials, the boat met her speed goals handily. 
Because no one was sure what might happen during high speed maneuvering, the
initial runs were performed at a constant depth and course.
	As her handlers became more confident, the boat was subjected to
increasingly tight turns at high speed. This testing proved particularly
valuable when Albacore participated in ASW drills with Navy destroyers. The
destroyers soon learned that the little sub was a quiet adversary. Her
smooth hull silently (to 1950's sound gear) sliced through depths even at
high speeds. When located and pursued, she routinely turned inside the
destroyer's turning radius and sped away.
	Speed was an entirely new arena for submarines. Before Albacore, most
submarines topped out at 10kts or less underwater. While Albacore's top
speed is still classified, she held the undersea speed record even after
the Skipjack class became operational - and they were rated, unofficially,
at 30+ kts submerged. Unofficial sources have indicated that speeds
approaching 50 knots might have been attained.
	The Albacore designers borrowed freely from aircraft technologies 
where appropriate. The single "driver" controls depth and course with an
aircraft-style wheel. Down angle was increased by pushing the wheel forward
and vice versa. The driver's station contains a seat belt for high-speed
maneuvering. The single-driver concept has been adopted in many foreign
submarines but most U.S. boats use a two man crew.  Control Station [130 Kb]


Phase II
	The results of Phase I testing had indicated that, at high speed, the
stresses at the base of the arms suspending the after control surfaces was
unacceptably high. As a result, in 1956 the Albacore was given a new set of
after control surfaces.
	The rudders and after diving planes were moved forward of the screw 
and arranged in a cruciform  or "+" configuration. In addition, the dorsal
rudder was eliminated and sound-deadening materials were added to many key
areas.  Even while the Albacore continued her work, a new generation of 
attack submarines were under construction using many of the advancements 
she had tested in phase I.
	In May 1956, the construction of the U.S.S. Barbel, first of a 
three-boat class, began. Barbel and her kin had the same tear-drop hull 
design as the Albacore and were constructed with the same HY-80 steel. 
The Barbel's were 219 feet long and had a 29 foot beam - just slightly 
greater than the Albacore. They were diesel/electric boats and were fully 
armed. They were also the last non-nuclear combat subs built by the U.S. 
Navy.
	The Skipjack program was run in parallel with the Barbel construction.
These boats combined the Albacore hull shape, single axis-mounted propeller
and HY-80 steel with a nuclear propulsion system. The S5W reactor performed
so well and proved so reliable that it was used for two decades in U.S. and
some British sub designs.
	As for the Albacore, much of her testing in this period was on Sonar
advancements.  Further changes in Phase II included the deletion of the 
bow planes in 1958 and, the following year, a larger, 14 foot propeller 
was installed and then deleted in the next phase.

Phase III
	The stern control surfaces were changed again in 1960. The rudders and
diving planes were rotated into an "X" shaped configuration. This
arrangement proved very popular with foreign submarine designers but has
never reappeared on U.S. submarines.
		The Dorsal rudder was reinstalled and enlarged and the boat 
was outfitted with speed brakes. These brakes - another concept borrowed 
from aviation - technology, consisted of 10 hinged panels ringing the 
after part of the ship. When needed, they were hydraulically opened into 
the waterflow, bringing the boat to a rapid stop.
	New Sonars were tested from the bow radar dome and a towed array was
fitted to the after part of the vessel.  In 1962, project "Bailout" was 
initiated. Still concerned about the high speeds Albacore was operating 
at, the Navy constantly searched for new ways to increase the safety 
margin for the crew.
	The Navy borrowed three B-47 drag chutes from Pease Air Force Base in 
New Hampshire. In a letter thanking the Air Force for it's assistance, 
The Albacore's CO wrote: 
	"The parachutes were attached to the after end of Albacore's fairwater
and successfully streamed while the ship was cruising submerged. The resulting
deceleration curves indicated that such a system effectively aided in 
emergency recovery." 
Project "Bailout" might not have been the most successful of Albacore's
tests but it certainly showed some creativity was at work.

Phase IV
	The predominate change in this phase was the installation of
counter-rotating screws. The drive shaft for the forward screw consisted of
a sleeve which housed the drive shaft for the after screw.
	A new system of blowing water ballast was also installed . The Albacore
and other U.S. subs ran a maze of piping run from the air banks, through
the control room and then on to the ballast tanks . In the Control Room,
the blow valves were manually operated to expel ballast in each tank.
	The new system brought the blow valves to the ballast tanks. These 
were operated by a single switch in the control room. The new system was 
simpler to operate and maintain. In case of emergency or loss of power, 
the ballast would be automatically blown and the vessel would quickly 
rise to the surface.
	In addition, new silver-zinc batteries replaced the conventional 
lead-acid type and the speed brakes were removed. Further high-speed 
trials were conducted to evaluate the propulsion system, and controls 
after which the Albacore received her last configuration changes.  The 
distance between her counter-rotating screws was later shortened, from 
10 feet to 5 feet.  Stern View [191 Kb]


	Further tests of communications equipment were completed before she 
was placed on reduced status in 1969 and subsequently decommissioned in 1972.
She had fulfilled her designers promises with distinction. A little submarine 
with a long legacy:
	"The research submarine Albacore introduced many of the features 
found in subsequent undersea craft; in many respects she was the 
beginning of the modern submarine era." wrote Norman Polmar in "The Ships 
and Aircraft of the U.S. Fleet."
	Mothballed at the Philadelphia Inactive Ship Maintenance Detachment, 
the Albacore story came to an end - almost.

Albacore Park
	For 10 years the Albacore sat in mothballs, her fate uncertain. Then a
group formed the Portsmouth submarine Memorial Association (PSMA) with the
express goal of bringing the Albacore back to her birthplace - the
Portsmouth Naval Shipyard.
	On May 3, 1985 responsibility for the submarine was transferred from 
the Navy to PSMA.  The boat had been towed the 575 miles from Philadelphia 
to Portsmouth, NH. Then, after a year-long delay, up the Piscatiqua river.
Her final resting place is almost a quarter mile inland from the river and
the journey required dismantling 30 feet of a railway trestle, carving out
a 70 foot portion of a four-lane highway, and raising the boat 27 feet from
the level of the river.
	Arriving on her concrete cradle system on October 3, 1985 the 
Albacore was finally home. Almost a year was required to prepare the 
Albacore for public viewing. Her hull was sandblasted and painted, the 
interior was cleaned, external power, lighting, heat and telecommunications 
were provided and a refurbished periscope was installed.
	The Navy granted permission for two doorways to be cut into the hull, 
fore and aft, to permit a one-way flow of visitors through the ship. 
A visitors center, with sufficient parking and access road, was constructed 
and the entire area was landscaped to provide a fitting setting for the boat.
	Finally, on Aug. 30, 1986 the complex - known as the Port of Portsmouth
Maritime Museum at Albacore Park - was opened to the public. Since then,
more than 360,000 have toured the submarine and visitors center.  Albacore Today [133 Kb]
     

Mark W. McKellar                                Web Page Posting Rights Only
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