From the first days of his ascension to power, Adolf Hitler planned to rebuild the Kriegsmarine into a world-class navy. Most of the world’s other major fleets included aircraft carriers, and so German naval authorities soon determined that the Reich would also require carriers.

Germany laid down its first carrier in December 1936, and launched the Graf Zeppelin two years later. It would never enter service, however: disputes between the Kriegsmarine and the Luftwaffe would delay the development of an air group, skepticism about the value of carriers would slow the project and, finally, the demands of the war prioritized other projects.

Had Graf Zeppelin entered service, however, it might have posed a formidable problem for the Royal Navy. Acting either alone or in support of Kriegsmarine battleships, Graf Zeppelin could have threatened Britain’s commercial lifeline, and at the very least made the antisubmarine campaign considerably more complicated.

Concept

The Royal Navy began converting ships into aircraft carriers before the end of World War I. By the early 1920s, Japan and the United States had joined the pack. The Washington Naval Treaty accelerated the pace of carrier construction, leading to the conversion of several large battle cruiser hulls into fleet carriers. France joined the party shortly thereafter, and even the Soviets and the Italians made abortive moves towards carrier construction.

The Treaty of Versailles sharply limited both German aviation and German naval construction, making aircraft carriers out of the question. When Hitler renounced those restrictions, however, carriers were back on the menu. The Anglo-German Naval Agreement allotted roughly forty thousand tons to German carrier construction, and initially the Reich determined to construct two nineteen-thousand-ton ships (roughly the size of American, Japanese and British fleet carriers). Although access to foreign aircraft carriers was limited, the Germans did manage to acquire some engineering materials from Japan during the design process.

The Ships

Expectations for the size of Graf Zeppelin and its sister increased across the process, as it became clear that the Anglo-German Naval Agreement did not pose a particularly important obstacle to what the Germans wanted. By the time of its launching, Graf Zeppelin was expected to displace thirty-five thousand tons, very large for an aircraft of the era, similar in size to the Essex-class carriers. Graf Zeppelin had a design speed of thirty-five knots, which would have made it the fastest carrier ever built (although it’s not at all clear that the final ship could have made that speed). It would also have carried a substantial antiaircraft armament for the period, which it would have needed given the lack of escorts in any plausible mission profile. Unlike American or Japanese carriers of the period, it would have had an armored flight deck.

Despite its size, the Germans did not expect Graf Zeppelin to carry a very large air group. Work on pilot training and aircraft development started in 1938. The responsibility for this development lay with the Luftwaffe, an interservice collaboration arrangement that has repeatedly proved unworkable in practice. In any case, the initial projected air group included twenty Fi 167 biplane torpedo bombers, ten Bf 109 fighters and thirteen Stuka dive bombers. As the project matured, the Germans dispensed with the Fi 167, and began working on plans to convert the Ju-87 into a torpedo bomber, as well as a carrier specialized fighter. Still, this collection would have been substantially inferior to the air groups normally deployed on American or Japanese carriers.

Employment

Long-range plans for Graf Zeppelin would have involved service with the regular body of the Kriegsmarine, supporting and protecting German battleships in operations against the Royal Navy and other foes. In the real war, however, Graf Zeppelin’s role would have been very different. Just as the cruisers and battleships of the Kriegsmarine found themselves committed to commerce raiding, Graf Zeppelin would have had to earn its keep in the hunt for merchant shipping in the Atlantic.

As an individual raider, Graf Zeppelin would have had some advantages over battleships such as Bismarck and Scharnhorst. Aerial recon would have made it much easier for the Graf Zeppelin to find targets, or to find targets for its partners. Strikes launched by bomber and torpedo aircraft could have wreaked havoc at long range, against not only British merchant shipping, but also against escorts and would-be interception squadrons. And Graf Zeppelin’s fighter contingent could have dealt with Swordfish biplanes of the sort that crippled Bismarck. It could also have operated in tandem with a battleship or heavy cruiser, increasing the scouting range and lethality of the raider formation, while also providing protection against British aircraft.

The biggest problems would have come not from the ship’s fuel, but rather from the expenditure of limited aviation stores. Sustaining carrier operations is hugely costly in terms of fuel, munitions and spare parts. The British, Americans and Japanese all dealt with this problem in different ways, and to different effect, but none of them employed carriers in long-range raiding ops detached from sources of supply. Germany did maintain a certain rump network of resupply ships in the Atlantic, but this would have struggled to keep Graf Zeppelin in operation for any extended period of time.

At the onset of war the Germans decided, probably correctly, that the Graf Zeppelins represented too much of an investment, given other priorities. The second ship of the class was broken up before launching, and work on Graf Zeppelin continued spasmodically across the war. Eventually, Allied naval dominance made the construction of further surface vessels pointless. Graf Zeppelin was scuttled in 1945, raised by the Soviets, and sunk as a target in 1947.

In the end, the need to develop operational experience with carriers may have posed the most difficult obstacle. In the wake of World War I, Japan, the UK and the United States spent almost two decades working through the problems and implications of carrier warfare. This included the development of aircraft, deck procedures, pilot training programs, resupply priorities, and aircraft management systems. The Germans would have had very little time to work on any of these, and could not have drawn on the expertise of any partners, apart from the distant Japanese. Simply getting Graf Zeppelin’s air group into shape would have taken more time than the Reich had to lose.

Still, Graf Zeppelin could have thrown a wrench into Allied naval warfighting plans; in the Arctic, for example, it could have caused major problems for Murmansk convoys. It is fortunate that the Nazis never had the opportunity to put it to use.

Robert Farley, a frequent contributor to TNI, is author of The Battleship Book. He serves as a Senior Lecturer at the Patterson School of Diplomacy and International Commerce at the University of Kentucky. His work includes military doctrine, national security, and maritime affairs. He blogs at Lawyers, Guns and Money and Information Dissemination and The Diplomat.

Image: The German aircraft carrier Graf Zeppelin. Wikimedia Commons/U.S. Navy