One Hundred Years of U.S. Navy Air Power (44 page)

  
10
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In July 1921 Senator William Borah of Idaho introduced a bill to stop construction of six battleships and three battle cruisers and to convert two of the battle cruisers already under construction to carriers (and also to buy four fleet submarines already authorized). This was advertised as disarmament by example, the emphasis being on the termination of contracts rather than on the new carriers and submarines, and Secretary of the Navy Theodore Roosevelt (a cousin of the late president) urged that the bill be abandoned for fear that it would affect the disarmament conference the United States had just called for the following November. It is significant here because it shows that the idea of converting two battle cruisers was current well before it was inserted into the Washington Treaty.

  
11
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Tonnage was a tricky yardstick, because different navies demanded different amounts of fuel to meet their strategic needs. The solution adopted at Washington was a new standard displacement, defined as the ship's displacement ready for battle less the two main consumables of fuel and reserve feed water. It was difficult to predict standard displacement because ships were designed to operate at a normal displacement including most of their fuel and reserve feed water; one consequence was that many early Treaty designs came out lighter than expected (and many later ones came out heavy, as designers sought to get closer to the limit). The phrase “ready for battle” also caused problems, as navies sought to shave nominal displacement by measures such as including only part of a ship's ammunition or excluding peacetime equipment such as ships' boats. Thus Taylor's 36,000 tons was an estimate based on a design that displaced over 40,000 tons in normal condition.

  
12
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The initial planned aircraft complement was two fighter, two torpedo bomber, and half an observation squadron (the other half of which would be on board Scouting Force battleships). Each fighter squadron consisted of twenty-seven aircraft (eighteen operating, nine reserve), each torpedo squadron of twenty-four aircraft (sixteen operating, eight reserve), and the observation squadron of eighteen aircraft (twelve operating, six reserve). On this basis the ship would operate thirty-six fighters, thirty-two torpedo bombers, and six observation planes, a total of seventy-four aircraft. Undated memo in GB 420-7 files for 1925–1931 from RADM W. A. Moffett, BuAer Chief. This was soon greatly exceeded.

  
13
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Thomas Wildenberg,
All The Factors of Victory: Admiral Joseph Mason Reeves and the Origins of Carrier Airpower
(Washington, DC: Potomac Books, 2003), is Reeves' only biography. It provided the dates used here.

  
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This innovation seems to have been made almost immediately, but Wildenberg does not mention it. It may have been associated with the creation of the Landing Signal Officer (LSO) position, as short landings required special assistance. The Royal Navy did not use LSOs. The guess as to the date comes from the way in which carrier design was described in the March 1926 C&R memo. As a motivation for increasing carrier capacity, Wildenberg emphasizes the idea that only a large fighter force could fend off attacks.

  
15
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Memo by BuAer Carrier Section, 1940, in GB 420-7. The equation of high performance and landing deck length helps explain why short Royal Navy carriers using high-performance fighters such as the Corsair and Seafire suffered so many barrier crashes compared to longer U.S. carriers.

  
16
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There was also considerable interest in rigid airships as fleet scouts, in some cases carrying fighters for self-protection. Although these aircraft were retired in the mid-1930s after some spectacular accidents, the idea survived, and the 1940 “Estimate of the Situation” looking toward the FY42 program included a big rigid airship (ZR, 3-million-cubic-feet capacity) in addition to the blimps used for ASW during World War II. It was never built.

  
17
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General Board files include a pair of design studies for maximum-size (27,000-ton) carriers dated 24 May 1924 showing that demanding high speed cost aircraft capacity (seventy-two aircraft in a 27.5-knot carrier, sixty in a 32.5-knot ship). At the other end of the scale, the Washington Treaty did not limit carriers displacing less than 10,000 tons. On 23 March 1925 the Bureau of Aeronautics suggested that such unlimited carriers should be the next considered by the U.S. Navy. It guessed that such a ship could carry sixty-four fighters or twenty-four torpedo bombers. On 31 March 1925 the Secretary of the Navy asked the General Board to consider a ship combining the attributes of a scout cruiser and a light cruiser, a new type of ship. To the General Board, this was much the same as the
Omaha
question raised five years earlier, since Congress would pay either for cruisers or for cruiser-size carriers, but not for both. The BuAer letter actually raised the wider question of carrier size versus aircraft capacity.

  
18
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Contemporary discussions refer to a non-watertight flight deck, well adapted to fittings such as arrester gear. Apparently this was not the superstructure flight deck adopted in the
Ranger
design; it was assumed that a watertight flat would be built a foot or two below the flight deck proper.
Ranger
originally had an open hangar deck mainly to accommodate the planned pair of athwartships catapults, which did not materialize.

  
19
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C&R planned a total of sixteen studies, varying different factors to show their influence on the design, as it had successfully done in the run-up to the first U.S. heavy cruiser design (
Pensacola
class). This systematic approach proved impossible partly because aircraft capability depended more on space and dimensions than on weight, and partly because there was no consensus as to which key factors were involved. The bureau therefore preferred not to submit the studies to the General Board, as they could not be used to draw conclusions accurately enough; however, they did indicate some key limiting conditions. Given the two 33,000-ton ex–battle cruisers, the 135,000-ton treaty total for carriers left 69,000 tons (if the experimental
Langley
were discarded, as the treaty permitted) for two 27,000-tonners, or three 23,000-tonners, or five 13,800-tonners, or six 10,000-tonners. The three tonnages investigated offered, respectively, totals of 192, 220, and 144 aircraft—showing that below a certain point, the ship was too small. C&R also took into account the possibility that the two big carriers would be modified so that their standard displacement could be given as 27,000 tons, leaving 81,000 tons for new carriers (this did not happen), or that the 36,000-ton displacement would be accepted, leaving 62,000 tons. This tonnage could be distributed among up to six carriers displacing between 10,800 tons (for the 62,000-ton total) and 27,000 tons (two ships in each case). No carrier with a mixed air group could be built on about 10,000 tons. Smaller carriers had about 15 percent more flight deck per airplane than larger ones. Although a larger number of smaller carriers would accommodate more aircraft, a smaller number of larger ones would cost much less per airplane; the first cost of five 13,800-tonners would be about 25 percent more than that of three 23,000-tonners, and the cost per airplane would be about 20 percent more. The smaller the carrier, the worse her protection. Although that might not count for above-water weapons that might cause a massive explosion, it certainly did count for torpedo attack.

  
20
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Characteristics were dated 1 November 1927. There had recently been a proposal to convert
Langley
's sister collier,
Neptune
, into another second-line training carrier, the resulting discussion probably helping to prompt the decision to build a first-line ship instead.

  
21
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Plans called for one to be an athwartships catapult on the hangar deck; cross-wind launches had been tested at the Naval Aircraft Factory (Philadelphia Navy Yard). The hangar deck location was attractive partly because space under the flight deck near the bow (needed for the machinery of a bow catapult) was so limited by the bridge, by the forward anti-aircraft guns, and by hangar equipment. Moreover, a flight-deck catapult would interfere with flight-deck operations. BuAer therefore proposed two double-ended battleship-type powder catapult on the hangar deck, one just abaft the after elevator and one abaft the uptakes, which themselves were abaft the two elevators, BuAer memo dated 10 March 1928 in GB 420-7. The hangar deck catapults were sometimes described as equivalent to the British and Japanese practice of providing a secondary short takeoff deck on the hangar deck level; catapults did not sacrifice as much hangar space. As detail design proceeded, the two elevators were brought together until they were about forty feet apart (General Board 420-7, 16 March 1928). By March 1930 a third elevator had been added, right aft, to make aircraft handling more flexible. This addition was suggested by aviators aboard
Lexington
and
Saratoga
. After aircraft landed, they were immediately re-spotted to the holding area amidships and prepared for another mission; sometimes that required flight-deck crews to work far into the night. The aft elevator could bring some of those aircraft down to the hangar deck, where they could also be prepared, and then back up into the spotting area amidships. Commander Aircraft Squadrons, Admiral Reeves, strongly recommended the third elevator. It became much less useful when operating practice changed to spot aircraft forward rather than amidships.

  
22
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As aircraft became heavier,
Ranger
's low speed became a real handicap. She could make about 29.4 knots at 16,000 tons, but by April 1939 her displacement was closer to 18,000 and her speed was about 28.7 knots. During a live bombing practice on 29 March 1939, with the surface wind running 4 knots, she was reduced to 24.2 knots and had to resort to long-run (on deck) takeoffs—which dramatically reduced the size of her deck spot, hence the power she could project (GB 420-7, reproduction of 7 April 1939 letter from Commander Aircraft, Battle Force). The point was raised because
Wasp
, 75 percent completed, would also be relatively slow. In 1938–1939 there was some interest in modifying both ships for increased speed, but that proved too expensive, and not worthwhile.
Wasp
actually produced more than her designed power, but nothing like enough to give her the desired carrier speed.

  
23
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In June 1933 the General Board rejected a suggestion that the ships not carry any torpedoes, in line with the earlier feeling that torpedo bombers were far too heavy and too slow to be useful on board carriers. Presumably the board was aware that new engines could substantially improve performance. The new torpedo bomber was the Douglas TBD Devastator, which in the mid-1930s did indeed seem to have spectacular performance. Aviation technology moved so fast that by 1942 (six years after entering service) the TBD was considered a low-performance death-trap at Midway. During the board's discussion, Rear Admiral E. J. King, then Chief of the Bureau of Aeronautics; Commander E. R. McClung of the BuOrd Aviation Ordnance Section; and Lieutenant Smith of the BuOrd Torpedo Section all opposed eliminating carrier torpedoes. The ninety-four-plane loadout is from a 1934 letter from the Supervisor of Shipbuilding at Newport News, mentioning a clause in the detailed specifications for the ship (GB 420-7 file for 1925–1939).

  
24
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BuAer, C&R, and the Bureau of Ordnance jointly suggested installing a small island at the forward corner of No. 2 elevator in a 22 November 1932 memo. Soon a larger island was being proposed; the General Board quickly approved this change. Memo for the record in GB 420-7, dated 23 December 1932, complaining that BuAer had first ruined the ship
by making her a flush-decker and then had demanded that the island be restored. BuAer pointed out that the
Ranger
design was based on experience with the flush-deck
Langley
, which operated only twenty airplanes. The air officer on a deck-edge platform could see far enough aft to see all of them land, controlling them. Once the complement had increased to thirty-two aircraft (i.e., once Reeves' full program had taken effect), it became difficult or almost impossible for the air officer to see aircraft landing after the twelfth or fifteenth.
Ranger
was intended to operate seventy-two aircraft. Once the ex–battle cruisers were in commission it became clear that the island was no problem; as of late 1932 no airplane had ever run into the ship's island, though one did hit an 8-inch turret. BuAer particularly wanted a larger island for
Ranger
to accommodate the air plot through which the carrier's strike aircraft were controlled (the islands of the big ex–battle cruisers accommodated such facilities). In this memo BuAer also admitted that even the low-powered
Langley
had suffered smoke problems.

  
25
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The Second Vinson-Trammell Act (17 May 1938) increased total carrier tonnage by 40,000 tons (29.6 percent, compared to an initial figure of 135,000 tons, left from the 1921 Washington Treaty). By way of comparison, total battleship tonnage increased by 135,000 tons (the whole 1921 carrier allowance) to 660,000 tons (25.7 percent) and cruisers by 20 percent. GB 420-2 contains a two-ocean paper dated 2 May 1939, giving necessary levels of superiority. With 5:3 superiority it would be possible to undertake an offensive in the Western Pacific “under favorable conditions” and the security of U.S. possessions as far west as Guam (but not the Philippines) could be ensured; with 4:3 Wake and the Aleutians would be safe and Guam would probably be safe. This paper strongly advocated fortifying Guam, on the grounds that with 4:3 superiority a fortified Guam would offer the equivalent of 5:3 (and with 5:3, the equivalent of 6:3, which in turn might equate to 380,000 tons of warships). On the other hand, with 4:3 inferiority, the Japanese would be able to attack into the eastern Pacific and perhaps capture the Aleutians. With 4:3 superiority in the Atlantic, U.S. forces should be able to guarantee the Western Hemisphere against German and Italian aggression. Parity would make it dangerous for the Germans and Italians to try to attack South America. The recommendations were based on 4:3 superiority in both oceans. The result was determined mainly by the strengths of the opposing fleets; Germany had ordered two carriers (neither ever completed) and Italy none. Both had, however, considerable battleship forces. Thus analysis based on opposing navies gave a battleship-heavy U.S. fleet (whose desired strength, as calculated in May 1939, was twenty-six battleships and sixteen carriers). A tonnage table included in the paper showed that the United States needed nearly twice the carrier tonnage made available by the 1938 Act (324, 841 versus 175,000 tons); the situation for battleships was only slightly less dire (1,043,169 tons needed versus 660,000 available)—and by no means had all the available 1938 tonnage been built.