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Balao Class, U.S. Submarines


Photograph of Balao-class submarine

Naval Historical Center #NH 98043

Schematic diagram of Balao class submarine

ONI 222


Specifications:


Tonnage

1526 tons standard
2010 tons submerged

Dimensions

311'0" by 27'3" by 16'8"
95.0m by 8.3m by 5.1m

Maximum speed     

20 knots surface
  9knots submerged
Dive
to 400 feet (120 m) as designed
to 600 feet (180m) in practice

Complement

80

Armament

6 21" (53cm) bow / 4 21" stern torpedo tubes (24 torpedoes)
1 5"/25 gun
Machinery
2-shaft diesel-electric (5400 shp surface, 2740 shp submerged)

Bunkerage

365 tons diesel oil

Range

11,000 nautical miles (20,000 km) at 10 knots on surface
96 nautical miles (180 km) at 2 knots submerged
Sensors
SD air warning radar
SJ surface search radar
Modifications

In late 1944, ST fire control radar became available.

Some shipped additional light antiaircraft, up to 1 40mm and  3 20mm guns.

Most modifications made to the Gatos were also made to the Balaos.


The Balaos were completed in 1943-45 and were essentially Gatos with strengthened hulls. This allowed them to dive deeper, which was tactically important when evading Japanese depth charge attacks. The boats so resembled the Gatos In every other respect that the Navy was able to conceal the design change throughout the duration of the war. The Japanese, who apparently were aware of the standard 250' (76 meter) design depth of the American prewar submarine classes, were unaware of the greater diving depth of the wartime submarine classes until this information was leaked by a Congressman back from a junket in the Pacific.

The increase in hull thickness without any other significant design changes was possible because the Gatos used a considerable amount of lead ballast. Increasing the hull thickness provided the extra weight needed to eliminate the expensive lead ballast while increasing the dive depth.

The hull plate on the Balaos was increased in thickness from 0.5625" (14.3mm) to 0.875" (22.2mm) and the plate material was upgraded from mild steel to high-tensile steel (HTS). It was calculated that this would increase the crush depth to 900 feet (270m) but other components, such as propeller shaft glands and the trim pump, could not be redesigned quickly to take the higher pressure and the maximum design operating depth was set to 400 feet (120m). As it turned out, the composition of high-tensile steel was changed from a chrome-vanadium steel alloy to a slightly weaker titanium-manganese steel alloy whose manufacture fewer scarce resources, so the large safety factor was beneficial. A Gould centrifugal pump was adopted in 1944 that could operate at 600 feet (180m) depth or more, and the refitted Balaos were thereafter able to more fully exploit their thick skins.

A particularly important improvement to the boats was the development of a slow, heavy-duty motor that replaced the older high-speed motors and reduction gears. Besides increasing reliability and saving space, the new motors eliminated the characteristic loud whine produced by the reduction gear. This was ready in time to be installed on new boats commissioned from July 1944 onwards. Another improvement was elimination of phenolic insulating materials, which burned when exposed to flame or electrical arcs (as from short circuits) to produce toxic smoke. The replacement, melamine insulation, has enough nitrogen in its chemical makeup to produce inert nitrogen gas when charred, which suppressed burning.

Units in the Pacific:

Haddock

arrived 1942-7-1

Balao

arrived 1943-2

Skate

completed 1943-4-15 (Mare Island)

Batfish

arrived 1943-5-4

Billfish

arrived 1943-6

Bowfin

arrived 1943-8-10

Archerfish

arrived 1943-9

Hake

arrived 1943-9-3

Apogon

arrived 1943-10

Aspro

arrived 1943-10

Haddo

arrived 1943-10

Tang

completed 1943-10-15 (Mare Island) Sunk by circling torpedo 1944-10-24  in Formosa Strait

Bang

arrived 1943-12

Burrfish

arrived 1943-12

Tilefish

completed 1943-12-28 (Mare Island)     

Sand Lance

arrived 1943-12-30

Bluegill

arrived 1944-1

Bullhead

arrived 1944-1 Sunk by aircraft 1945-8-6 in Bandung Strait

Golet

arrived 1944-1 Sunk 1944-6-14 off northeast Honshu

Picuda

arrived 1944-1-13

Pampanito

arrived 1944-2-7

Parche

arrived 1944-3-1

Guitarro

arrived 1944-3-7

Spadefish

completed 1944-3-9 (Mare Island)

Perch

arrived 1944-3-27

Guavina

arrived 1944-3-28

Seahorse

completed 1944-3-31 (Mare Island)

Pilotfish

arrived 1944-4-9

Pintado

arrived 1944-4-10

Piranha

arrived 1944-4-10

Shark

arrived 1944-4-10 Sunk 1944-10-24 in Formosa Strait

Pipefish

arrived 1944-4-20

Plaice

arrived 1944-4-25

Barbero

arrived 1944-5
Sterlet arrived 1944-5-5

Pomfret

arrived 1944-5-15

Trepang

completed 1944-5-22 (Mare Island)

Hardhead

arrived 1944-5-27

Barbel

arrived 1944-6 Sunk by aircraft 1945-2-4 off Palawan

Becuna

arrived 1944-6

Besugo

arrived 1944-6

Redfish

arrived 1944-6-13

Hawkbill

arrived 1944-6-16

Ronquil

arrived 1944-6-21

Atule

arrived 1944-7

Baya

arrived 1944-7

Bergal

arrived 1944-7

Queenfish

arrived 1944-7

Segundo

arrived 1944-7-1

Scabbardfish     

arrived 1944-7-8

Sea Devil

arrived 1944-7-18

Blackfin

arrived 1944-8

Blenny

arrived 1944-8

Razorback

arrived 1944-8-1

Spot

completed 1944-8-3 (Mare Island)

Sea Dog

arrived 1944-8-8
Jallao
arrived 1944-8-9

Icefish
arrived 1944-8-15

Sea Fox

arrived 1944-8-20

Blower

arrived 1944-9

Sea Cat

arrived 1944-9-4

Spikefish

arrived 1944-9-23

Blueback

arrived 1944-10

Boarfish

arrived 1944-10

Brill

arrived 1944-10

Sea Owl

arrived 1944-10-9

Sea Poacher

arrived 1944-10-11

Sea Robin

arrived 1944-10-12

Springer

completed 1944-10-18 (Mare Island)

Charr

arrived 1944-11

Kraken

arrived 1944-11-4

Threadfin

arrived 1944-11-15

Sennet

arrived 1944-11-29

Bugara

arrived 1944-12

Lagarto

arrived 1944-12-12

Lamprey

arrived 1944-12-24

Tench

arrived 1944-12-27

Bumper

arrived 1945-1

Piper

arrived 1945-1-1

Lionfish

arrived 1945-1-15

Tigrone

arrived 1945-1-23

Hackleback

arrived 1945-1-25

Tirante

arrived 1945-2

Trutta

arrived 1945-2-10

Lizardfish

arrived 1945-2-13

Torsk

arrived 1945-2-25

Quillback

arrived 1945-3

Toro

arrived 1945-3-15

Loggerhead

arrived 1945-3-17

Thornback

arrived 1945-3-27

Dentuda

arrived 1945-4

Manta

arrived 1945-4-3

Moray

arrived 1945-5-5

References

Alden (1979)

Blair (1975)

DANFS

Friedman (1995)

Worth (2001)



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