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Lexington Class, U.S. Fleet Carriers


Photograph of Lexingon with packed flight deck

National Archives #80-G-416362

Schematic diagram of Lexington class fleet carrier

ONI 222


Specifications:


Displacement

36,000 tons standard

Dimensions

888' by 106' by 24'2"
270.7m by 32.3m by 7.4m

Maximum speed      

35 knots

Complement

2791

Aircraft

866'2" (264m) flight deck
2 elevators
1 catapult
80 aircraft total

Armament

4x2 8"/55 guns
12x1 5"/25 AA guns
48x1 0.50 machine guns

Protection

1437 tons:
7" (178mm) belt inclined 11 degrees
7" (178mm) bulkheads
1"+1" (25mm+25mm) STS armored deck
1.5"+1.5" over steering
0.75" turrets
2" conning tower
0.75"/0.375"/0.375" torpedo bulkheads
Machinery
4-shaft General Electric turboelectric drive (180,000 shp)
16 water-tube boilers

Bunkerage

3600 tons fuel oil
125,000 gallons (473,000 liters) aviation gasoline

Range

10,950 nautical miles (20,200 km) at 15 knots.
Fuel consumption approximately 395 tons per day during flight operations.

Munitions

1248 tons

Sensors

CXAM1 air search radar

Modifications:
In April and May 1942 the 8" guns and 0.50 machine guns were removed from both ships. Lexington received 4x4 1.1"/75 AA guns, 22x1 20mm Oerlikon AA guns, and two Mark 4 radars.  Saratoga received 4x2 5"/38 dual-purpose guns, 4x4 1.1" guns, and 22x1 20mm Oerlikons. She also had her 5"/25s replaced by 8x1 5"/38s and she received SC and two Mark 4 radars.

In late 1942 Saratoga received an additional 30x1 20mm Oerlikons, and her 1.1" mounts were all replaced with quad 40mm Bofors.

In late 1944 Saratoga replaced 28 of her 20mm Oerlikons with 20x4 40mm Bofors, and her radar suite was upgraded to include SK, SM, and two Mark 12/22 radars. She also had two bow catapults installed, received a starboard bulge raising her displacement to 40,000 tons, had her flight deck lengthened to 909'5" (277.2 m) and had her fuel oil bunkerage increased to 9748 tons.

Completed in 1927, the Lexingtons were laid down as battle cruisers in 1920-1921 but were completed as carriers under the terms of the Washington Naval Treaty. By the time the decision was made to convert the ships to carriers, in late 1922, the hulls were essentially complete and the heavy belt armor was already in place. A voluminous hangar deck was constructed atop each hull that was 450' (137m) long, 70' (21m) wide, and 21' (6,.4m) deep. This remained the largest hangar of any carrier class in the world until well after the war ended. There was a 105' (30m) maintenance shop aft of the hangar and a 120' (37m) hold for spare aircraft just below the hangar deck. This allowed the ships to carry 80 first-generation aircraft in their hangars and holds, in addition to aircraft on the flight deck. The hull was plated clear to the flight deck, a practice that was abandoned on later American carrier designs.

The authorized air group on 7 December 1941 was one fighter squadron of 18 fighters, one scout and one bombing squadron of 21 dive bombers each, and a torpedo squadron of 12 torpedo bombers. Together with the air group commander's dive bomber, this totaled 73 aircraft. The fighter squadron should ideally have been 27 aircraft, but a shortage of fighters meant that this number was not available until the war had been going on for some time. During the aftermath of the Midway operation, Saratoga ferried 107 aircraft to Enterprise and Hornet, but it could not have effectively operated this many.

Their engines were the most powerful of any warship afloat until the launching of the North Carolina in late 1941. The boiler uptakes were trunked together into a single massive funnel aft of the island that gave these ships a distinctive profile. The tall funnel also solved the problem of smoke drifting across the flight deck.

The ships were given a cruiser-like armament of 8" guns, the maximum permitted by the disarmament treaties, on the dubious theory that in their scouting role they might have to tangle with enemy light surface forces. The 8" mounts were an unhappy compromise between conflicting requirements: Their position in twin turrets forward and aft of the island economized on protection and reduced their footprint at the level of the hangar deck, but it also meant the guns were impractical to fire except to starboard. The 5" dual-purpose guns were placed in unshielded single mounts in a catwalk surrounding the flight deck.

They were notoriously unmaneuverable, unsurprising considering that they were the longest ships in the world in 1942, but they were also very tough ships, the Saratoga twice surviving hits from deadly Japanese torpedoes. They had excellent subdivision due to the use of turboelectric drive, which allowed the engine and boiler rooms to be laid out alternately down the centerlines of the ships.

Impressive as these ships were, they were less cost-effective than later carrier designs, such as the Yorktowns and Essexes, which accomplished nearly as much on significantly lighter displacements. Their heavy belt armor was largely wasted on ships against which the greatest threat would prove to be aircraft-borne bombs and torpedoes. However, as conversions whose design could draw on little prior experience, they were remarkably successful.

Units in the Pacific:

Lexington      

Task Force 12 en route Midway      

Sunk by aircraft 1942-5-8 in the Coral Sea

Saratoga

San Diego


Photo Gallery

Painting of Lexingon battle cruiser design

Library of

Congress

Models showing conversion from battlecruiser to carrier

U.S. Navy

Lexington as originally completed with 8" turrets

U.S. Navy

The two Lexingtons off Diamond Head

U.S. Navy

Saratoga from above

U.S. Navy

Bow of Saratoga

NARA

Outboard funnel of Saratoga

U.S. Navy

Bridge of Saratoga seen from elevator

Library of

Congress

Funnel area

NARA

5"/25 guns

U.S. Navy


References

DANFS

Chesneau (1992)

Friedman (1983)

Gogin (2014; accessed 2014-8-2)

Lundstrom (2006)

Worth (2001)



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