The Pacific War Online Encyclopedia
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|Tonnage||37,487 tons standard displacement
|Dimensions||729' by 108'4" by 35'6"
222.20m by 33.02m by 10.82m
|Maximum speed||27 knots|
guns (180 rounds per gun)
10x2 5"/38 dual-purpose guns (440 rounds per gun)
4x4 1.1"/75 AA guns
12 0.50 machine guns
|Protection||15,370 tons or 41% of displacement:
(305mm) belt tapering to 6" (152mm) below the waterline, sloped 15 degrees and backed by 0.75" (19mm) STS
3.75" to 2.2" (95mm to 56mm) patches over magazines sloped 15 degrees
4.1" to 3.6" + 1.4" (104mm to 91mm + 36mm)
0.75" to 0.625" (19mm to 16mm) splinter deck
1.5" (38mm) bomb deck
11.1" (281mm) bulkheads tapering to 1.9" (48mm)
14.9"/11.1"/6" (378mm/282mm/152mm) steering belt/bulkheads/crown
16"/7"/9.8"/11.8" (406mm/178mm/249mm/300mm) turret front/roof/side/rear
16"/14.7"/11.5" (406mm/373mm/292mm) barbette beam/front/rear
1.95" (59mm) STS secondary battery
16"/14.7"/7" (406mm/373mm/178mm) conning tower beam/centerline/roof
5-bulkhead void-liquid-liquid-liquid-void torpedo protection (0.44", 0.75", 0.625", 0.375" and 0.375" or 11mm, 19mm, 16mm, 10mm and 10mm mild steel bulkheads from inboard to outboard) designed to withstand a 700 lb (318 kg) explosive charge.
30,800 yards (18,200 to 28,200 meters) versus 14" shell
21,300 to 32,000 yards (19,500 to 29,300 meters) versus light 16" shell
Below 8750 feet (2670m) versus a 1600 lb (726 kg) armor piercing bomb
||4-shaft General Electric geared
8 Babcock & Wilcox three-drum boilers
|Bunkerage||5540 tons fuel oil|
|Range||13,500 nautical miles (25,000 km) at 15 knots|
Mark 3 fire control radar (two sets)
Mark 4 fire control radar (three sets)
1942-4: 40x1 20mm Oerlikon AA guns
1942-6: Total of 28x1 0.50 machine guns.
1942-9: Quad 1.1" guns replaced with 10x4 40mm Bofors AA guns. 0.50 machine guns landed. Six more 20mm guns added. CXAM1 replaced with SG surface search radar and a fourth Mark 4 set.
1943-3: Total of 14x4 40mm guns.
1943-11: Total of 15x4 40mm guns.
1944-3: Total of 53 20mm guns. Mark 3 radar removed and replaced with second SG set, SK air search radar, 2 Mark 8 fire control radar sets, and Mark 27 range finding radar.
1945-8: Total of 8x2, 20x1 20mm guns.
1942-4: Added 20x1 20mm guns.
1942-6: Total of 28x1 0.50 machine guns.
1942-9: 2x4 1.1" guns added. Total of
40 20mm guns. CXAM1 replaced with SG surface search radar and a fourth Mark 4 set.
1942-12: 0.50 machine guns and 5 20mm guns removed.
1943-4: Total of 64 20mm guns
1943-6: 1.1" guns replaced by 15x4 40mm Bofors guns.
1944-4: Total of 1x4, 63x1 20mm guns. Mark 3 radar removed and replaced with second SG set, SK, 2 Mark 8 sets, and Mark 27.
1945-8: 1x4, 8x2, 63x1 20mm guns. Radar upgraded with SR and SCR-720 sets.
The North Carolinas were the
first U.S. battleships commissioned since
the Colorados in 1921-1923, and
plans were started in 1928, years before they
were actually laid down. Under the treaty framework,
limited to 35,000 tons and guns
were initially limited to 14" (356mm). This
was increased to 16" (406mm) after they were laid down but before they
launched. Proposed designs were generally "slow" (23 knots) or
(30 knots) and varied from the odd (hybrid battleship-carriers with three
catapults and 20 bombers
forward and two quadruple turrets aft, Scheme
F) to more conventional designs. Design philosophies shifted as
different designers entered and left the design group, and a wide range
of design concepts were reviewed. Eventually, some speed (27
instead of 30 knots) and armor
(protection against 14" shells instead
of against 16") were sacrificed to attain the desired armament (twelve
guns as laid down, nine 16" as completed). The speed requirement was selected specifically to allow the North Carolinas to exceed the speed of the Japanese Kongos; Naval Intelligence was unaware that the Kongos had already been modernized to a speed of better than 30 knots.
The ships were designed during a period of rapid improvement in machinery. The Bureau of Engineering initially pushed for the adoption of a 1,200 psi / 950 degrees F plant, but eventually agreed to a 565 psi / 850 degrees F plant — still remarkable at a time when plants being used in most other ships were 300 psi / 572 degrees F. This advanced machinery made the speed of the North Carolinas possible. The twin rudders provided a very tight turning radius, which allowed Washington to turn inside of British carriers and battleships when she served with the British Home Fleet in 1942.
Machinery dispersal was enhanced by the use of a unit
arrangement, with four self-contained compartments each with two
boilers and one set of engines. This was cramped and made heavy armor
protection impossible for the uptakes, but it minimized the effects of
single torpedo hits.
The North Carolinas
had excellent firepower, and
their numerous 5"/38s
made for a substantial
antiaircraft capability. They
also featured a sloped armor
improved its effectiveness by perhaps 30%, so that a 12" belt
the same protection as a 16" belt. The zone of immunity was 20,000 to
30,800 yards (18,200 to 28,200 meters) versus 14" shells and 21,300 to
32,000 yards (19,500 to 29,300 meters) versus light 16" shells. The
deck armor was designed to be proof against a 1600 lb (726 kg) armor
piercing bomb dropped from up to 8750 feet (2670m). If there was
anything lacking in the
design, it was the machinery and underwater protection.
Once launched, problems with vibrations were encountered, which led to a lengthy delay before the ships were considered combat ready. Various fixes were tried, and North Carolina earned the nickname "Showboat" for the large number of day voyages out of New York harbor. The use of four bladed propellers on the outboard shafts and five bladed propellers on the inboard shafts reduced the vibrations enough to permit the ships to join the fleet. But the problem was never entirely fixed: The after range-finder vibrated excessively at certain speeds, the after fire control tower had to be fitted with large external braces, and the turbine and gear casings also had to be braced.
North Carolina was hit by a torpedo from I-15 on 15 September 1942. The torpedo hit the most vulnerable portion of the ship (abeam the #1 turret) and penetrated the side protective system, with the flash from the explosion penetrating the forward turret handling room. This put #1 turret out of commission, but effective damage control allowed a high speed of 18 knots to be maintained and eliminated the 5.5 degrees of list within six minutes.
Washington took part in the Naval Battle of Guadalcanal and gutted Kirishima with nine 16" shells (out of 75 fired) and 40 5" shells from a range of 8,400 yards. The Japanese scuttled Kirishima the following day. On 1 February 1944, Washington rammed Indiana, demolishing Washington's bow. The captain of Indiana admitted responsibility for the collision at the subsequent Board of Inquiry and was relieved of command.
Both North Carolina and Washington finished out the war in the Pacific. They were retained in the postwar fleet slightly longer than the subsequent South Dakota class, largely because of their greater habitability due to a less cramped design.
Dullin and Garzke (1976)
Gogin (2010; accessed 2013-2-4)
The Pacific War Online Encyclopedia © 2007-2009, 2013-2014 by Kent G. Budge and John E. Kollar. Index
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