This lack of clarity led to features such as cruiser-type guns for commerce raiding and defense against British cruisers, that were either eliminated from or not included in American and Japanese carrier designs.

Progress was again delayed, this time by the demand for newer planes specifically designed for carrier use and the need for modernizing the ship in light of wartime developments.

[1] The design staff decided that the new carrier would need to be able to defend itself against surface combatants, which necessitated armor protection to the standard of a heavy cruiser.

[7] Two years later, Großadmiral (Grand Admiral) Erich Raeder presented an ambitious shipbuilding program called Plan Z which would build up the Kriegsmarine to a point where it could challenge the British Royal Navy in the North Sea.

[13] The bulges served mainly to improve Graf Zeppelin's stability but they also gave her an added degree of anti-torpedo protection and increased her operating range because selected compartments were designed to store approximately 1500 additional tons of fuel oil.

[11] The Graf Zeppelin class's power plant was to consist of 16 La Mont high-pressure boilers, similar to those used in the Admiral Hipper-class heavy cruisers.

Their four sets of geared turbines, connected to four shafts, were expected to produce 200,000 shp (150,000 kW) and propel the carrier at a top speed of 35 knots (40 mph; 65 km/h).

With a maximum bunkerage capacity of 5000 tons of fuel oil (prior to the addition of bulges in 1942), the Graf Zeppelins' calculated radius of action was 9,600 miles (15,400 km) at 19 knots (35 km/h; 22 mph).

However, wartime experience on ships with similar power plants showed such estimates were highly inaccurate, and actual operational ranges tended to be much lower.

At the bow, the carriers were to have an open forecastle and the leading edge of her flight deck was uneven (mainly due to the blunt ends of her catapult tracks), but it did not appear likely that would have caused any undue air turbulence.

Careful wind-tunnel studies using models confirmed this, but they also revealed that their long low island structure would generate a vortex over the flight deck in these tests when the ship yawed to port.

[17] The Graf Zeppelin class had three electrically operated elevators positioned along the flight-deck's center-line: one near the bow, abreast the forward end of the island; one amidships; and one aft.

In the hangars, aircraft were to be hoisted by crane - a method also proposed for the Essex-class carriers of the United States Navy, but rejected as too time-consuming - onto collapsible launch trolleys.

The insulated compartments were to be electrically heated to a temperature of 20 °C (68 °F) in order to prevent ice from forming on the cylinder piping and control equipment as the compressed air was vented during launches.

[22] To facilitate rapid catapult launches and eliminate the necessity of time-consuming engine warm-ups,[Note 1] up to eight aircraft were to be kept in readiness aboard the German carriers on their hangar decks by the use of steam pre-heaters.

Original drawings show four additional wires fore and aft of the forward lift, possibly intended to allow recovery of aircraft over the bows, but these may have been deleted from the ship's final configuration.

These were mounted, two each, at the four corners of the carriers' upper hangar deck, positions that raised the possibility the guns would be washed out in heavy seas, especially those in the forward casemates.

However, the Naval Armaments Office misinterpreted his proposal to save space by pairing them and instead doubled the number of guns to 16, resulting in a need for increased ammunition stowage and more electrically operated hoists to service them.

Later, a stronger braking winch was supplied by Atlas-Werke of Bremen and this allowed heavier aircraft, such as the Fieseler Fi 167 and Junkers Ju 87, to be tested.

[5] This was later changed to 30 Bf 109 fighters and 12 Ju 87 dive-bombers as carrier doctrine in Japan, Great Britain and the United States shifted away from purely reconnaissance duties toward offensive combat missions.

[33] By December 1940, the RLM decided to complete only seven carrier-equipped Bf 109T-1s and to finish the remainder as land-based T-2s since work on Graf Zeppelin had ceased back in April and there appeared to be little likelihood she would then be commissioned any time soon.

At the end of 1941, when interest in completing Graf Zeppelin revived, the surviving Bf 109 T-2s were withdrawn from front-line service in order to again prepare them for possible carrier duty.

By the time work on the carrier resumed two years later in May 1942, the Fi 167 was no longer considered adequate for its intended role and the Technische Amt decided to replace it with a modified torpedo-carrying version of the Junkers Ju 87D.

[36] Ten Ju 87C-0 pre-production aircraft were built and sent to the testing facilities at Rechlin and Travemünde where they underwent extensive service trials, including catapult launches and simulated deck landings.

[37] Work on developing a torpedo-carrying version of the Ju 87D for anti-shipping sorties in the Mediterranean had already commenced in early 1942 when the possibility again arose that Graf Zeppelin might be completed.

[39] On 1 August 1938, four months prior to Graf Zeppelin's launch date, the Luftwaffe formed its first carrier-based air unit, designated Trägergruppe I/186, on Rugia Island near Burg.

By October shipyard construction delays resulted in disbandment of the air group as it was considered too large and costly to maintain given the uncertainty over when the two vessels would be ready for sea trials.

By August the three squadrons were reorganised into Trägergruppe II/186 under the command of Major Walter Hagen in anticipation that Graf Zeppelin would be ready for service trials by the summer of 1940.

By late January 1943 Hitler had become so disenchanted with the Kriegsmarine, especially with what he perceived as the poor performance of its surface fleet, that he ordered all of its larger ships taken out of service and scrapped.

Work on Flugzeugträger B began in 1938 but was halted on 19 September 1939 because, now that Germany was at war with Great Britain and France, priority had shifted to U-boat construction.