Greater Underwater Propulsion Power Program
Encyclopedia
The Greater Underwater Propulsion Power Program (GUPPY) was initiated by the United States Navy
after World War II to improve the submerged speed, maneuverability, and endurance of its submarine
s. (The "Y" in the acronym was added for pronounceability.)
The Navy began the program by testing and reverse engineering
two captured German Type XXI U-boats: U-2513
and U-3008
. That analysis led to four goals — increasing the submarines' battery capacity, streamlining the boats' structures, adding snorkel
s, and improving fire control
systems. The Navy immediately focused on designing a new class of submarines, but the Bureau of Ships
believed that the vast fleet of existing Gato
, Balao
, and Tench
class submarines could be modified to incorporate the desired improvements. In June 1946, the Chief of Naval Operations
approved the GUPPY project. The initial two boat test program, implemented by the Portsmouth Naval Shipyard
, eventually grew into several successive conversion programs. Those upgrades proceeded in seven variants, in the following order: GUPPY I, GUPPY II, GUPPY IA, Fleet Snorkel, GUPPY IIA, GUPPY IB, and GUPPY III. Some boats that went through an early phase were then upgraded further in a later phase.
and radar
mast supports. To reduce hydrodynamic drag
, one of the periscopes was deleted. No snorkel was fitted, due to difficulties in adapting the snorkel to the fleet boat. Deck guns and their associated containers were removed. An SV radar aerial was added to the top of the sail, creating a distinctive side bulge. All capstans, cleats, and rail stanchion supports were redesigned so they could be retracted or removed when rigged for dive. Most notably, the sharp V-shaped "fleet boat bow" was replaced with a distinctive rounded "Guppy bow" that improved submerged performance.
These modifications changed not only the boats' appearance, but also their terminology: After a GUPPY conversion, the faired structure around the boat's conning tower
and mast supports was called the "sail."
Internally, the boats underwent considerable rearrangement to accommodate larger battery wells and batteries of greatly increased electrical power. The batteries were of a new design. Compared with the original Sargo
battery, the Guppy battery used a greater number of thinner plates that would generate higher current for a longer time. However, these batteries had a shorter life, 18 months versus the five years of the Sargo battery, and took longer to charge. They also required ventilation to remove hydrogen gas, and required cooling water to the battery terminals and termination bars. Four 126-cell batteries were installed in enlarged battery wells that replaced former storage, ammunition, and refrigeration spaces. These four batteries could be connected in series or parallel, providing a wide range of voltages and currents, and thus a wide range of speeds.
In the maneuvering room, two or four of the earlier high-speed motors and reduction gears were replaced by slow-speed motors. All open-front switchboards were replaced with enclosed splash-proof cabinets. Lighting and other "hotel" electrical loads were converted to use 120 volt 60 hertz
alternating current
, and ship electronics to use 120 volt 400 hertz AC. A new air conditioning
system of greatly increased capacity was also installed.
In service, these boats offered greatly improved underwater performance. Pomodon reached 17.8 knots surfaced and 18.2 knots (35.7 km/h) submerged, Odax slightly less.
Some boats with a Portsmouth Sail had an SV radar and needed extra room to house the aerial, thus had a bulge at the sail top. Later modifications put the SS or SS2 radars on these and other boats that had a smaller aerial and had an indicator with interlocks, allowing the mast to be housed only with the aerial in certain angular positions. Also, some GUPPY II and GUPPY III boats had their sails extended higher above the waterline, the "Northern Sail", to raise the bridge, allowing it to be manned in more severe weather.
All boats converted during the GUPPY II program that originally had high-speed drive motors with reduction gears had these replaced with low-speed direct-drive motors, producing 2500 horsepower (1.9 MW) per shaft.
The two GUPPY I boats, Odax and Pomodon, were modified to GUPPY II standard.
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Externally, the GUPPY IIA differed from the GUPPY II and IA by having only three diesel exhaust outlets, whereas the earlier conversions had four.
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) (became HNLMS Zeeleeuw (S-803) Royal Netherlands Navy
) (became HNLMS Walrus (S-802) Royal Netherlands Navy
)
room, berthing, electronics, and storerooms. The removal of the sonar room from the forward torpedo spaces allowed an increase in the number of reloads. Crew spaces were also refurbished. As in the GUPPY IIA conversion, one diesel engine was removed.
From 1961 to 1963, eight more GUPPY II boats were upgraded to GUPPY III standard. These boats differed from Tiru by adding a 15 foot (4.6 m) section forward of the control room. They also retained all four diesel engines. This increased the boat's length to 322 feet (98.1 m) and raised surfaced displacement to approximately 1975 tons.
All boats received the BQG-4 PUFFS passive ranging sonar, identifiable by the three fin-like sonar domes added to the superstructure. The conning tower in the sail gained an additional five foot (1.5 m) section to accommodate the Mk 101 fire control system and Mk 37 director. All GUPPY III boats received a plastic sail.
The GUPPY III conversion was part of the Fleet Rehabilitation and Modernization
(FRAM) program. All 24 GUPPY II boats were originally slated to receive the GUPPY III upgrade, but budgetary constraints limited the program to a total of nine boats. Despite their extensive modifications and upgrades, the GUPPY III boats served only slightly longer than the rest of the GUPPY fleet.
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)
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...
after World War II to improve the submerged speed, maneuverability, and endurance of its submarine
Submarine
A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...
s. (The "Y" in the acronym was added for pronounceability.)
The Navy began the program by testing and reverse engineering
Reverse engineering
Reverse engineering is the process of discovering the technological principles of a device, object, or system through analysis of its structure, function, and operation...
two captured German Type XXI U-boats: U-2513
Unterseeboot 2513
German submarine U-2513 was a Type XXI U-boat of the Kriegsmarine, that was operated by the United States Navy for several years after World War II.-Kriegsmarine:...
and U-3008
Unterseeboot 3008
The German submarine U-3008 was a Type XXI U-boat of the German Kriegsmarine that served in the United States Navy for several years after World War II....
. That analysis led to four goals — increasing the submarines' battery capacity, streamlining the boats' structures, adding snorkel
Submarine snorkel
A submarine snorkel is a device which allows a submarine to operate submerged while still taking in air from above the surface. Navy personnel often refer to it as the snort.-History:...
s, and improving fire control
Fire control
control of fire 'control of fire' is the practice of reducing the heat output of a fire, or reducing the area over which the fire exists, or suppressing or extinguishing the fire by depriving a fire of fuel, oxygen or heat ....
systems. The Navy immediately focused on designing a new class of submarines, but the Bureau of Ships
Bureau of Ships
The United States Navy's Bureau of Ships was established by Congress on June 20, 1940, by a law which consolidated the functions of the Bureau of Construction and Repair and the Bureau of Engineering. The new Bureau was to be headed by a Chief and Deputy-Chief, one selected from the engineering...
believed that the vast fleet of existing Gato
Gato class submarine
The United States Navy Gato class submarine formed the core of the submarine service that was largely responsible for the destruction of the Japanese merchant marine and a large portion of the Imperial Japanese Navy in World War II...
, Balao
Balao class submarine
The Balao class was a successful design of United States Navy submarine used during World War II, and with 122 units built, the largest class of submarines in the United States Navy. An improvement on the earlier Gato class, the boats had slight internal differences...
, and Tench
Tench class submarine
Tench-class submarines were a type of submarine built for the United States Navy between 1944 and 1951. They were an evolutionary improvement over the Gato and Balao classes, only about 35 to 40 tons larger, but more strongly built and with a slightly improved internal layout...
class submarines could be modified to incorporate the desired improvements. In June 1946, the Chief of Naval Operations
Chief of Naval Operations
The Chief of Naval Operations is a statutory office held by a four-star admiral in the United States Navy, and is the most senior uniformed officer assigned to serve in the Department of the Navy. The office is a military adviser and deputy to the Secretary of the Navy...
approved the GUPPY project. The initial two boat test program, implemented by the Portsmouth Naval Shipyard
Portsmouth Naval Shipyard
The Portsmouth Naval Shipyard , often called the Portsmouth Navy Yard, is a United States Navy shipyard located in Kittery on the southern boundary of Maine near the city of Portsmouth, New Hampshire. It is used for remodeling and repairing the Navy's ships...
, eventually grew into several successive conversion programs. Those upgrades proceeded in seven variants, in the following order: GUPPY I, GUPPY II, GUPPY IA, Fleet Snorkel, GUPPY IIA, GUPPY IB, and GUPPY III. Some boats that went through an early phase were then upgraded further in a later phase.
GUPPY I Program
The prototype GUPPYs, and (both Portsmouth-built Tench boats), appeared in 1947. Externally, they featured improved streamlining of the bridge and shears structures, and periscopePeriscope
A periscope is an instrument for observation from a concealed position. In its simplest form it consists of a tube with mirrors at each end set parallel to each other at a 45-degree angle....
and radar
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...
mast supports. To reduce hydrodynamic drag
Drag (physics)
In fluid dynamics, drag refers to forces which act on a solid object in the direction of the relative fluid flow velocity...
, one of the periscopes was deleted. No snorkel was fitted, due to difficulties in adapting the snorkel to the fleet boat. Deck guns and their associated containers were removed. An SV radar aerial was added to the top of the sail, creating a distinctive side bulge. All capstans, cleats, and rail stanchion supports were redesigned so they could be retracted or removed when rigged for dive. Most notably, the sharp V-shaped "fleet boat bow" was replaced with a distinctive rounded "Guppy bow" that improved submerged performance.
These modifications changed not only the boats' appearance, but also their terminology: After a GUPPY conversion, the faired structure around the boat's conning tower
Conning tower
A conning tower is a raised platform on a ship or submarine, often armored, from which an officer can con the vessel; i.e., give directions to the helmsman. It is usually located as high on the ship as practical, to give the conning team good visibility....
and mast supports was called the "sail."
Internally, the boats underwent considerable rearrangement to accommodate larger battery wells and batteries of greatly increased electrical power. The batteries were of a new design. Compared with the original Sargo
USS Sargo (SS-188)
USS Sargo , the lead ship of her class of submarine, was the first ship of the United States Navy to be named for the sargo.Her keel was laid on 12 May 1937 by the Electric Boat Company in Groton, Connecticut. She was launched on 6 June 1938 sponsored by Mrs. Chester W. Nimitz , and commissioned on...
battery, the Guppy battery used a greater number of thinner plates that would generate higher current for a longer time. However, these batteries had a shorter life, 18 months versus the five years of the Sargo battery, and took longer to charge. They also required ventilation to remove hydrogen gas, and required cooling water to the battery terminals and termination bars. Four 126-cell batteries were installed in enlarged battery wells that replaced former storage, ammunition, and refrigeration spaces. These four batteries could be connected in series or parallel, providing a wide range of voltages and currents, and thus a wide range of speeds.
In the maneuvering room, two or four of the earlier high-speed motors and reduction gears were replaced by slow-speed motors. All open-front switchboards were replaced with enclosed splash-proof cabinets. Lighting and other "hotel" electrical loads were converted to use 120 volt 60 hertz
Hertz
The hertz is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of the sine wave, particularly those used in radio and audio applications....
alternating current
Alternating current
In alternating current the movement of electric charge periodically reverses direction. In direct current , the flow of electric charge is only in one direction....
, and ship electronics to use 120 volt 400 hertz AC. A new air conditioning
Air conditioning
An air conditioner is a home appliance, system, or mechanism designed to dehumidify and extract heat from an area. The cooling is done using a simple refrigeration cycle...
system of greatly increased capacity was also installed.
In service, these boats offered greatly improved underwater performance. Pomodon reached 17.8 knots surfaced and 18.2 knots (35.7 km/h) submerged, Odax slightly less.
GUPPY II Program
The GUPPY II conversion (SCB 47), implemented from 1947 to 1951, was generally similar to the GUPPY I, except for retention of both periscopes and introduction of the recently perfected snorkel. The addition of three new masts — snorkel induction, snorkel exhaust, and ESM mast — required more room in the upper portion of the sail. BuShips approved two different sail designs:- The "Electric BoatElectric boatWhile a significant majority of water vessels are powered by diesel engines, with sail power and gasoline engines also remaining popular, boats powered by electricity have been used for over 120 years. Electric boats were very popular from the 1880s until the 1920s, when the internal combustion...
Sail" had a straight trailing edge, round windows, a wider top and a more rounded forward edge. - The "Portsmouth Sail" had a thinner top, curved trailing edge, square windows and a sharper lower forward edge. It was put on all boats that used the government plans for the conversion.
Some boats with a Portsmouth Sail had an SV radar and needed extra room to house the aerial, thus had a bulge at the sail top. Later modifications put the SS or SS2 radars on these and other boats that had a smaller aerial and had an indicator with interlocks, allowing the mast to be housed only with the aerial in certain angular positions. Also, some GUPPY II and GUPPY III boats had their sails extended higher above the waterline, the "Northern Sail", to raise the bridge, allowing it to be manned in more severe weather.
All boats converted during the GUPPY II program that originally had high-speed drive motors with reduction gears had these replaced with low-speed direct-drive motors, producing 2500 horsepower (1.9 MW) per shaft.
The two GUPPY I boats, Odax and Pomodon, were modified to GUPPY II standard.
GUPPY II Boats
| (became ARA Sante Fe (S-21) Argentine Navy Argentine Navy The Navy of the Argentine Republic or Armada of the Argentine Republic is the navy of Argentina. It is one of the three branches of the Armed Forces of the Argentine Republic, together with the Army and the Air Force.... ) (Became Guanabara (S-10) Brazilian Navy Brazilian Navy The Brazilian Navy is a branch of the Brazilian Armed Forces responsible for conducting naval operations. It is the largest navy in Latin America... ) (Became Goiás (S-15) Brazilian Navy Brazilian Navy The Brazilian Navy is a branch of the Brazilian Armed Forces responsible for conducting naval operations. It is the largest navy in Latin America... ) (Became Ceará (S-14) Brazilian Navy Brazilian Navy The Brazilian Navy is a branch of the Brazilian Armed Forces responsible for conducting naval operations. It is the largest navy in Latin America... ) (Became Bahia (S-12) Brazilian Navy Brazilian Navy The Brazilian Navy is a branch of the Brazilian Armed Forces responsible for conducting naval operations. It is the largest navy in Latin America... ) (Became Rio Grande do Sul (S-11) Brazilian Navy Brazilian Navy The Brazilian Navy is a branch of the Brazilian Armed Forces responsible for conducting naval operations. It is the largest navy in Latin America... ) |
GUPPY IA Program
BuShips devised the GUPPY IA (SCB 47A) program of 1951 as a cheaper alternative to the GUPPY II conversion. While the GUPPY IA conversion included most features of the GUPPY II, it omitted the four-cell battery configuration and extensive internal rearrangement associated with it. Instead, the GUPPY IA retained the original battery wells, fitted with more powerful Sargo II batteries. These batteries featured electrolyte agitation, battery cooling, and open tank ventilation. They also had a longer life than the Guppy batteries, though shorter than the original Sargo battery. The sonar room was relocated from the forward torpedo room to a space under the galley. Compared to the GUPPY II, the GUPPY IA offered lower cost, better habitability, and easier maintenance at the expense of underwater performance.Fleet Snorkel Program
When the Navy realized that it would not be able to fund all the GUPPY conversions it desired, it devised the Fleet Snorkel program (SCB 47B) as a means of adding the minimum necessary modifications to fleet boats. The Fleet Snorkel modernization added a snorkel, a streamlined sail, a higher capacity air-conditioning system, and a more powerful electrical system. The deck guns and auxiliary diesel were removed. Unlike the GUPPY conversions, the Fleet Snorkel boats retained their original deck structure, bow, and storage batteries. Submerged performance of the Fleet Snorkel boats was therefore significantly inferior to any GUPPY conversion. Despite their limited features, the Fleet Snorkel boats served almost as long as the more modern GUPPY boats. Three boats, Piper, Sea Owl, and Sterlet, received a large BQR-4A bow sonar.The GUPPY IA program was succeeded by the nearly identical GUPPY IIA program (SCB 47C), implemented from 1952 to 1954. The GUPPY IIA, however, further alleviated the cramped internal conditions of earlier conversions by removing one forward engine and replacing it with pumps and air conditioning machinery. Some boats had the high-pressure air compressors relocated to the lower level of the forward engine room. The freezer and refrigerator units were moved to the space under the galley, and the sonar room was relocated to the forward end of the pump room. Sargo II batteries were installed in the existing battery wells.
Externally, the GUPPY IIA differed from the GUPPY II and IA by having only three diesel exhaust outlets, whereas the earlier conversions had four.
GUPPY IB Program
GUPPY IB was an informal designation for a limited upgrade and modernization given to four boats for transfer to foreign navies. These boats had snorkels and were generally similar to the GUPPY IA, except that they were not equipped with the modern sonar, fire control systems, or ESM. The two Italian boats were of the thin-skinned Gato class.GUPPY IB Boats
(became ITNS Enrico Tazzoli (S-511) Marina MilitareMarina Militare
The Italian Navy is the navy of the Italian Republic. It is one of the four branches of military forces of Italy; formed in 1946, from what remained of the Regia Marina . As of 2008, the Italian Navy had 35,200 active personnel with 180 commissioned ships, 19 Floating Docks, and 123 aircraft...
) (became ITNS Leonardo da Vinci (S-510) Marina Militare
Marina Militare
The Italian Navy is the navy of the Italian Republic. It is one of the four branches of military forces of Italy; formed in 1946, from what remained of the Regia Marina . As of 2008, the Italian Navy had 35,200 active personnel with 180 commissioned ships, 19 Floating Docks, and 123 aircraft...
) (became HNLMS Zeeleeuw (S-803) Royal Netherlands Navy
Royal Netherlands Navy
The Koninklijke Marine is the navy of the Netherlands. In the mid-17th century the Dutch Navy was the most powerful navy in the world and it played an active role in the wars of the Dutch Republic and later those of the Batavian Republic and the Kingdom of the Netherlands...
) (became HNLMS Walrus (S-802) Royal Netherlands Navy
Royal Netherlands Navy
The Koninklijke Marine is the navy of the Netherlands. In the mid-17th century the Dutch Navy was the most powerful navy in the world and it played an active role in the wars of the Dutch Republic and later those of the Batavian Republic and the Kingdom of the Netherlands...
)
GUPPY III Program
The GUPPY II conversions suffered from very cramped internal conditions due to the four-battery configuration. The GUPPY III program (SCB 223) was devised to address this problem. In 1959, became the prototype conversion. It was cut in half and lengthened with a 12.5 foot (3.8 m) section forward of the control room to create space for a new sonarSonar
Sonar is a technique that uses sound propagation to navigate, communicate with or detect other vessels...
room, berthing, electronics, and storerooms. The removal of the sonar room from the forward torpedo spaces allowed an increase in the number of reloads. Crew spaces were also refurbished. As in the GUPPY IIA conversion, one diesel engine was removed.
From 1961 to 1963, eight more GUPPY II boats were upgraded to GUPPY III standard. These boats differed from Tiru by adding a 15 foot (4.6 m) section forward of the control room. They also retained all four diesel engines. This increased the boat's length to 322 feet (98.1 m) and raised surfaced displacement to approximately 1975 tons.
All boats received the BQG-4 PUFFS passive ranging sonar, identifiable by the three fin-like sonar domes added to the superstructure. The conning tower in the sail gained an additional five foot (1.5 m) section to accommodate the Mk 101 fire control system and Mk 37 director. All GUPPY III boats received a plastic sail.
The GUPPY III conversion was part of the Fleet Rehabilitation and Modernization
Fleet Rehabilitation and Modernization
The Fleet Rehabilitation and Modernization program of the United States Navy extended the lives of World War II-era destroyers by shifting their mission from a surface attack role to that of a submarine hunter...
(FRAM) program. All 24 GUPPY II boats were originally slated to receive the GUPPY III upgrade, but budgetary constraints limited the program to a total of nine boats. Despite their extensive modifications and upgrades, the GUPPY III boats served only slightly longer than the rest of the GUPPY fleet.
GUPPY III Boats
(became Amazonas (S-16) Brazilian NavyBrazilian Navy
The Brazilian Navy is a branch of the Brazilian Armed Forces responsible for conducting naval operations. It is the largest navy in Latin America...
) (became Goias (S-15) Brazilian Navy
Brazilian Navy
The Brazilian Navy is a branch of the Brazilian Armed Forces responsible for conducting naval operations. It is the largest navy in Latin America...
)
External links
"New Subs Are Undersea Aircraft" , June 1949, Popular Science detailed article on the new Guppy Class- http://guppysubmarinetribute.homestead.com/Tribute.html