The ''Cachalot''-class submarines were a pair of medium-sized

submarine A submarine (or sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely op ...

s of the

United States Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...

built under the tonnage limits of the

London Naval Treaty The London Naval Treaty, officially the Treaty for the Limitation and Reduction of Naval Armament, was an agreement between the United Kingdom, Japan, France, Italy, and the United States that was signed on 22 April 1930. Seeking to address is ...

of 1930. They were originally named ''V-8'' and ''V-9'', and so were known as " V-boats" even though they were unrelated to the other seven submarines (''V-1'' through ''V-7'') constructed between

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was List of wars and anthropogenic disasters by death toll, one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, ...

and

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...

. An extensive study was conducted to determine the optimum submarine size under the treaty restrictions, factoring in total force, endurance, and percentage of the force that could be maintained on station far from a base, as in a Pacific war scenario. Joseph W. Paige of the Navy's

Bureau of Construction and Repair The Bureau of Construction and Repair (BuC&R) was the part of the United States Navy which from 1862 to 1940 was responsible for supervising the design, construction, conversion, procurement, maintenance, and repair of ships and other craft for the ...

(BuC&R) developed the basic design, but the builder,

Electric Boat An electric boat is a powered watercraft driven by electric motors, which are powered by either on-board battery packs, solar panels or generators. While a significant majority of water vessels are powered by diesel engines, with sail power ...

, was responsible for detailed arrangement; this was fairly bold, since Electric Boat had not built any new submarines since finishing four obsolescent boats for Peru. The previous V-boats were all built in naval shipyards. ''Cuttlefish'' was the first submarine built at EB's facility in

Groton, Connecticut Groton is a town in New London County, Connecticut located on the Thames River. It is the home of General Dynamics Electric Boat, which is the major contractor for submarine work for the United States Navy. The Naval Submarine Base New London is ...

; construction of previous Electric Boat designs had been subcontracted to other shipyards, notably Fore River Shipbuilding of

Quincy, Massachusetts Quincy ( ) is a coastal U.S. city in Norfolk County, Massachusetts, United States. It is the largest city in the county and a part of Metropolitan Boston as one of Boston's immediate southern suburbs. Its population in 2020 was 101,636, making ...

.Friedman, p. 193

Design

Although externally much like the later "fleet submarines," internally the ''Cachalot''s were quite different. Due to pressure from the Submarine Officers Conference, they featured full double hulls adapted from the ''

Kaiserliche Marine {{italic title The adjective ''kaiserlich'' means "imperial" and was used in the German-speaking countries to refer to those institutions and establishments over which the ''Kaiser'' ("emperor") had immediate personal power of control. The term wa ...

'''s ''U-135'', direct-drive diesel-electric propulsion systems, a separate crew's mess (reinstated thanks to EB's rearrangement of the internal layout; Portsmouth would follow soon after), and considerable space around the

conning tower A conning tower is a raised platform on a ship or submarine, often armored, from which an officer in charge can conn the vessel, controlling movements of the ship by giving orders to those responsible for the ship's engine, rudder, lines, and gro ...

within the large bridge fairwater (which was drastically cut down in

when the 3-inch (76 mm)

deck gun A deck gun is a type of naval artillery mounted on the deck of a submarine. Most submarine deck guns were open, with or without a shield; however, a few larger submarines placed these guns in a turret. The main deck gun was a dual-purpose ...

was relocated forward of the bridge). The 3-inch gun was selected because it was felt at the time that a larger gun would encourage submarine captains to fight on the surface against superior anti-submarine ships; this remained the standard submarine

until early in

, when war experience showed that a larger gun was needed. EB greatly expanded on the use of

electric welding Electric resistance welding (ERW) is a welding process where metal parts in contact are permanently joined by heating them with an electric current, melting the metal at the joint. Electric resistance welding is widely used, for example, in manuf ...

that had been pioneered by Portsmouth on the earlier V-boats. On ''Cuttlefish'', most of the outer hull and the fuel tanks were welded, while the inner pressure hull remained riveted. Portsmouth, while welding non-critical areas on ''Cachalot'' like the superstructure, piping brackets, support framing and interior tanks, continued to use riveting for both the inner and outer hulls. During the war, the riveted boats would leak fuel oil. The as-built engine specifications were two BuEng-built,

MAN A man is an adult male human. Prior to adulthood, a male human is referred to as a boy (a male child or adolescent). Like most other male mammals, a man's genome usually inherits an X chromosome from the mother and a Y chromo ...

-designed M9Vu 40/46 nine-

cylinder A cylinder (from ) has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base. A cylinder may also be defined as an ...

Alden, p.210. two-cycle direct drive main

diesel engine The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-cal ...

s, each, with one BuEng MANAlden, p.210. two-cycle auxiliary diesel engine, driving a

electrical generator In electricity generation, a generator is a device that converts motive power ( mechanical energy) or fuel-based power ( chemical energy) into electric power for use in an external circuit. Sources of mechanical energy include steam turbines, ...

.Friedman, p. 310 The auxiliary engine was for charging batteries or for increased surface speed via a diesel-electric system providing power to the main

electric motor An electric motor is an electrical machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a wire winding to generate f ...

s. Due to the full double hull design, the external tanks proved too narrow for easy maintenance,Alden, p.39. and the MAN diesels were a constant headache, demanding re-engining with

General Motors The General Motors Company (GM) is an American Multinational corporation, multinational Automotive industry, automotive manufacturing company headquartered in Detroit, Michigan, United States. It is the largest automaker in the United States and ...

- Winton four-cycle 16-258 engines in 1936-38. On the other hand, the class made a major contribution to habitability, when ''Cuttlefish'' was the first sub fitted with

air conditioning Air conditioning, often abbreviated as A/C or AC, is the process of removing heat from an enclosed space to achieve a more comfortable interior environment (sometimes referred to as 'comfort cooling') and in some cases also strictly controlling ...

, and to effectiveness, being first fitted with the Mark I Torpedo Data Computer (TDC).Alden, p.39. This replaced the older "banjo" and "Is/Was" used in S-boats, as described in Ned Beach's ''Run Silent, Run Deep''.

Service

Despite the calculation process, size reduction had gone too far with the ''Cachalot''s, limiting their patrol endurance. The subsequent ''Porpoise'' class were about 300 tons larger, and each succeeding class was incrementally larger than its predecessors through the submarines of 1941 (with exception of the two experimental submarines of 1939). After three

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contine ...

war patrols each, the ''Cachalot''s were relegated to training duties in September 1942, as numerous ''Gato''-class boats became available.

Ships in class

Notes

References

* Schlesman, Bruce and Roberts, Stephen S., "Register of Ships of the U.S. Navy, 1775–1990: Major Combatants" (Greenwood Press, 1991), * Lenton, H. T. ''American Submarines (Navies of the Second World War)'' (Doubleday, 1973), * Silverstone, Paul H., ''U.S. Warships of World War II'' (Ian Allan, 1965), * Campbell, John ''Naval Weapons of World War Two'' (Naval Institute Press, 1985),
Whitman, Edward C. "The Navy's Variegated V-Class: Out of One, Many?" ''Undersea Warfare'', Fall 2003, Issue 20
* https://web.archive.org/web/20140322093118/http://www.fleetsubmarine.com/sublist.html * Gardiner, Robert, ''Conway's All the World's Fighting Ships 1922–1946'', Conway Maritime Press, 1980. . * Friedman, Norman ''US Submarines through 1945: An Illustrated Design History'', Naval Institute Press, Annapolis:1995, . * Johnston, David "No More Heads or Tails: The Adoption of Welding in U.S. Navy Submarines", ''The Submarine Review'', June 2020, pp.46-64.

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