CF Flying Deck Cruiser

In 1921, President Warren G. Harding appointed William A. Moffett as the first chief of the newly created Bureau of Aeronautics with the accompanying rank of rear admiral. Admiral Moffett had overseen flight training and aircraft maintenance instruction during World War I while at the Great Lakes Naval Training Center and used aerial spotters with great success during gunnery exercises while commanding the Mississippi.

Moffett was an outstanding naval officer, and he devoted those same considerable abilities to the cause of naval aviation. From 1921 until 1933, he conducted a sustained campaign against traditionalists to convince the naval establishment of the value of airpower. Moffett sent airpower to sea aboard battleships and cruisers. Moffett leveraged his political connections to remain in his post as bureau chief for an unprecedented twelve years and to garner congressional support to expand the nascent aviation program during years of lean budgets. He pushed the development of fleet aircraft carriers, airships, and the flying-deck cruiser. Not everything Moffett touched turned to gold. The flying-deck cruiser never left the drawing board.

As part of the Washington Naval Treaty, the battle cruisers Saratoga and Lexington were both converted into aircraft carriers. Unfortunately, these ships together used up nearly half the carrier tonnage quota allowed to the US Navy under the Treaty, so that less tonnage remained for future construction. Furthermore, a frugal Congress kept naval appropriations so small that no new carriers could be built. The result was that the Navy, well aware of the potential of the aircraft carrier for scouting and attack duties, began to consider aircraft carrier / cruiser hybrids.

Given that resources were too scarce to have both, the hope was to combine the best features of both ship types into a single cruiser class. During World War I the British had also been experimenting with conversions of light cruisers to carriers, though when the war ended these studies were discontinued. The idea of a cruiser-hulled carrier kept generating interest, however. More decks meant a higher sortie rate for aircraft and less risk if an aircraft-carrying ship was lost.

When the Washington Fleet Conference of 1921-22 imposed limits on the total tonnage of aircraft carriers for the great naval powers, and the idea of small carriers was rekindled. Several loopholes in the Washington agreement left the Americans with the chance to use up to 25 percent of the alloted cruiser tonnage for conversion to ships with flight decks. During the early hearings on the construction of aircraft carriers in 1923 Admiral Rodgers had emphasized the loophole in the treaty that allowed the Navy to "make as many 10,000 ton carriers as we like. That is to say 10,000 tons without fuel, the same as we can build cruisers.."

However, in the mid-1920s the Navy's General Board decided that it would not be a good idea to "sacrifice" a cruiser for a carrier that would displace less than 10,000 tons. The minimum displacement for a satisfactory carrier had to be 14,000 tons.

In May of 1927, Lieutenant Commander Bruce G. Leighton wrote an impressive paper on light carriers. His forecast of possible use for these smaller vessels proved to be remarkably prescient. In his paper Leighton foresaw the use of these ships in antisubmarine warfare, fleet operations support, reconnaissance, attacks on enemy warships, and the reduction of enemy shore bases.

About this time the Navy was quite taken with the idea of a "flying deck cruiser." This hybrid vessel of approximately 10,000 tons would be a cross-pollination of light cruiser and aircraft carrier. Moffett proposed a vessel of 10,000 tons displacement that would be an aircraft carrying cruiser which can operate upward of 40 planes of the intermediate or smaller types. Such a complement of planes can be used alternately on gunnery observation, tactical scouting, fighting [air defense], smoke laying or bombing missions with bombs carrying at least 400 pounds of explosive. About 650 feet long, the forward half of this vessel would be a 6-inch gunned, triple-turreted cruiser. The after half would have a 350-foot angled flight deck (a design years ahead of its time), with hangar space for twenty-four aircraft, according to another design. It was an imaginative concept.

The 1930 London Naval Conference placed further limits on the building of battleships, cruisers, destroyers, and submarines. The London Treaty specifically defined aircraft carriers in such a way as to remove the "loophole" that might allow the building of carriers of 10,000 tons or less. New provisions were created using two separate articles. Article 3 of the London Treaty prevented the counting of "landing-on or flying-off platforms" against a nation's overall carrier tonnage. Also, Article 16 of Part III of the treaty stipulated that "Not more than twenty-five percent of the allowed total tonnage in the cruiser category may be fitted with a landing-on platform or deck for aircraft."

John Kuehn notes " ... the idea for a flying deck cruiser was inserted into the language of the 1930 London Naval Treaty. Such a ship would serve multiple purposes. First and foremost it would get naval aviation to the fleet by employing a different class of ship - ships that could carry more than just two or three planes but not as many as the larger carriers. Such ships promised operational flexibility because aviation would be distributed more evenly throughout the fleet. The risk of losing one of the two big carriers as had happened in the famous Fleet Problem IX, and thus losing a significant percentage of the aviation available to protect and assist the battle line, would be ameliorated by the addition of such ships. Spreading aviation throughout the fleet seemed to make sense given the limited evidence available at the time. When viewed in this light the flying deck cruiser was a conceptual breakthrough rather than a mere tactical improvement."

In 1930 Congress authorized the construction of the flying deck cruiser for $19-20 million before the Navy was ready to build it. The Navy was in the unusual position of having the money already authorized to build a ship for which it had no design.

Within a few months of the conclusion of the London Naval Treaty, the Bureau of Construction and Repair was working on plans for what was called a flying-deck cruiser. Moffett developed a plan to build seven flying deck cruisers by 1936. The design was to incorporate as much carrier capability as possible while sacrificing the least amount of cruiser capability. All of this in a ship whose displacement could not exceed 10,000 tons.

In December 1930 Captain Van Keuren of BuC&R who presented an initial design for a cruiser with two triple-mount 6-inch gun turrets in front, one in the back, and a flight deck with island roughly amidships. The size of the ship was extraordinary, almost 650 feet in length, using every ton of the 10,000 allowed by the London Treaty. The flight deck was off center to the port side of the vessel to counter-balance the island. BuAer presented a counter-design that removed the island completely because it interfered with flight operations. But eliminating the island would seriously degrade the fire control directors' lines of sight and fields of view for the 6- and 5-inch guns.

The General Board considered designs ranging from standard cruisers with just a few additional aircraft to flush deck designs almost indistinguishable from the sorts of light aircraft carriers that were later developed from cruiser hulls for WW II. On 22 December 1930 BuC&R presented seven different designs for the Board to consider, designated with alphanumerics. Of these designs the G and D-series (D, D1, and D2) elicited the most interest. The G-design was the most cruiser-like and the E and F designs were flush deck designs. The D-series were true compromise designs. They included an island, three forward 6- inch gun turrets, as well as an innovative design for a folding smoke stack on the starboard side. The design template selected for further study was that of the D series, but renamed A2. The flying deck cruiser was the world's first angled-deck carrier design, an innovation that was a generation ahead of its time.

The flying deck cruiser was removed from the construction budget for 1933 in late 1932 due to the governmental economies necessitated by the Depression. In the early 1930s, war games demonstrated the low cost-effectiveness of the armored cruiser, identified tactical defects in battleships, and were instrumental in introducing the all-big-gun battleship. Later, war games decided the characteristics of the first purpose-built aircraft carrier Ranger and eliminated the proposed flying-deck cruiser.

With the election of Roosevelt and the implementation of the "New Deal", specifically manifested in the National Industrial Recovery Act of 1933, the US Navy suddenly found itself in the unexpected position of no longer needing to compromise between carriers and cruisers. Given the funds necessary to build both types of ships, the flying-deck cruiser idea was scrapped for the moment.

In 1933 Retired Admiral Hilary Jones called the ship "a hermaphrodite - neither a real cruiser nor a real airplane carrier. It has all the weaknesses of both and none of the efficient characteristics of either." Admiral Joseph M. Reeves, commander in chief of the United States Fleet, summed up the case against the flying-deck cruiser in a memo to the General Board dated 08 October 1934 "Each study shows it to be a hybrid type entirely unsuitable as a cruiser or a carrier." The idea of the flying deck cruiser, though kept alive until 1940, finally disappeared into the land of what-might-have-been.