German aircraft carrier development began in 1918, when a design was drawn up to convert the incomplete liner Ausonia into an aircraft carrier. The 518-foot long, 11,300 ton, turbine-powered vessel was under construction at Blohm & Voss Hamburg for the Italian firm Sitmar, and had been launched in April of 1915 but never completed. The plan would have built hangers and a full flight deck above the existing main deck of the vessel, with a small island and funnel to starboard and a short, downward-sloping launch deck at the bow. Two 270-foot hangers were provided for wheeled aircraft, with a 422-foot hanger below for seaplanes. The aircraft compliment was to be 13 fixed wing or 19 folding wing seaplanes and 10 wheeled aircraft. The sketch design was quite advanced for the time, reminiscent of HMS Courageous as converted in the 1920s. However work was never started for a variety of reasons, and the end of the war and resulting treaties made the Germans completely abandon all thoughts of aircraft carriers.
* * * * * * * * Link to drawing of proposed conversion * * * * * * * *
As Germany began to rearm in the 1930s, the Kriegsmarine saw value in vessels capable of supporting aircraft. In 1933 a design team led by Wilhelm Hadeler came up with theoretical and preliminary sketch design for a full deck carrier capable of carrying 30 aircraft. The design has not survived, but apparently Hadeler's ideas made an impression, for by the start of 1934 the German design and construction authority laid out the following requirements for an aircraft carrier:
Displacement of approximately 20,000 tons
Speed of 33 knots
Compliment of 50-60 aircraft
Armor protection equal to a contemporary
light cruiser
Anti-surface armament of 8 x 8-inch guns
The high speed requirement was to allow the carrier to escape enemy capital ships, while the heavy surface armament was to allow the ship to hold her own in a surface fight against enemy cruisers. The gun battery in particular seems out of place, and both hindsight and a glance at contemporary designs (like the USS Ranger) reveal that other navies had concluded that strong anti-surface batteries did not belong on a carrier.
The surface combat capability is often blamed in the German's lack of previous experience with aircraft carriers, as the USA made a similar error when designing the Lexington class conversions in the early 1920s, as did the Japanese with the first-generation Akagi and Kaga conversions. But the German decision to include a strong surface combat ability was not just a repeat of the first-generation confusion of the role a carrier would play, and it must be placed in the proper context.
The German aircraft industry was also inhibited by the Treaty of Versailles. Aircraft at the time, and in particularly in Germany, were short-range, rather fragile machines. Naval aircraft in particular were considered to be inferior to their land based counterparts: due to their need for heavier construction their performance and range was less than that of land based aircraft. The short range of naval aircraft meant that the carriers were operating fairly close to enemy fleets, and when forced to sail into the wind at high speed to launch their aircraft it was quite likely that aircraft carriers would encounter enemy surface units, especially cruisers scouting in advance of the enemy main body. The fragility of aircraft in general and inferior performance of naval aircraft in particular meant that while their strike ability was appreciated, it was generally accepted that carrier aircraft were a 'one time shot.' The thought of sustained carrier operations in combat, as was to be demonstrated in WWII in the Pacific, simply had not crossed anyone's mind because the aircraft of the day were simply not up to it. So the German designers included a strong gun battery so the ship would have some fighting value even once her aircraft were expended. US designers followed the same line of thinking in the 1930s, when they were strongly exploring the concept of the flight deck cruiser.
Guided by the above requirements, Hadeler set about designing a possible German aircraft carrier. The newly formed Luftwaffe was of no help, consumed as it was with its own rapid build up, and was unable to provide even speculative aircraft sizes to set the hanger height, flight deck length, and elevator & catapult capacity. So Hadeler went under the assumption that existing land based planes could be modified for carrier use, and arresting gear and catapults would overcome the land based aircraft's need for long runways. His new sketch design came in at 23,000 tons, showing a very high freeboard for operations in the Atlantic and North Sea, 35-knot speed, two centerline elevators, and a strong gun battery. The designers replaced the 8 inch guns with an equal number of 5.9 inch guns in casemates, and added 10 * 4-inch anti-aircraft guns in twin turrets, plus numerous 20mm single weapons, all to help protect the ship from land-based aircraft. Like the earlier Ausonia conversion, the British Courageous & others, and the Japanese Akagi & others, a short flying off deck was included to launch fighters over the forecastle directly from the upper hanger.
In 1935 the Anglo-German Treaty officially gave Germany the right to construct aircraft carriers, and set the size of the German fleet at 35% of the Royal Navy. This meant Germany could have a theoretical 42,750 tons of aircraft carriers based on the 135,000 tons allowed to Britain, but as the Royal Navy had not built to the full strength the German tonnage was only 38,500. Hitler gave the go ahead to design and construct two carriers, now limited to 19,250 tons each.
Hadeler and his design team went to work refining his sketches and developing them into complete design, with the first ship (Carrier "A") to be authorized in the 1936 budget and the second (Carrier "B") in the 1938 budget. Tonnage was trimmed away from the preliminary design, and a one-knot drop in speed was accepted. Officials from the Construction Office visited the HMS Furious at Navy Week, where they learned little but were at least able to see an actual carrier in person. Negotiations with the Japanese yielded a visit to the carrier Akagi by a three-man technical team, along with about 100 pages of plans and blueprints dealing with flight operation systems. Based on these, Hadeler's design team added a third centerline elevator, and based on input from the Luftwaffe they eliminated the fighter launch deck. Hadeler suggested that the 8 * 5.9-inch guns should be mounted in double casemate mounts, rather than singles, to save weight. However, his suggestion was misunderstood by Hitler, and the original layout was retained with twin mounts in each casemate. So the gun battery now included 16 * 5.9-inch guns, though no provisions were made to increase magazine capacity or crew quarters for the extra gun crews. This may indicate that Hadeler simply acquiesced to the 'political powers that be' but intended to reverse the decision later. By the time it was all said and done, the ship had grown back to 23,300 tons standard displacement, thought the published figure continued to be the 'treaty legal' 19,250 tons.
Before the design was 100% finalized it was approved by the commander of the Navy, and the construction contract was given to Deutsche Werke Kiel AG on November 16, 1935. However, the yard was busy building the heavy cruiser Blucher, the battlecruiser Gneisenau, four destroyers, four submarines, and the large supply ship Franken. Carrier "A" was finally laid down on December 28, 1936, on the slipway vacated by the launch of the Gneisenau. Carrier "B" had been promised to Friedrich Krupp Germania Shipyard in Kiel, but that vessel could not be laid down until after the launch of the cruiser Prinz Eugen in the second half of 1938. Work on the second carrier was to be done at a very slow pace, so any changes or lessons learned from the construction of "A" could be incorporated into the second unit. Two additional units were by now being planned, and it was expected that "A" could be launched in December 1938 and "B" in June 1940, with "C" and "D" to be laid down in 1941 and in service by 1944.
Design Statistics are as follows
Dimension Feet Meters Length Overall 861 262.50 Length at waterline 820 250 Beam at waterline 88' 6" 27 Beam at flighdeck 98' 5" 30 Flightdeck length 800' 6" 244 Flightdeck height above waterline 51 15.60 Overall height 73' 10" 22.5 Draft at normal load displacement 24 7.35 Draft at full load displacement 24' 11" 7.60
Weapons Number Rounds 5.9 inch, 15cm SKC/28 16 1,840 4.1 inch, 10.5cm SKC/33 12 4,800 3.7cm L/80 SKC/30 22 88,000 20mm L115 SKC/30 7 14,000
Displacement, claimed 19,250 tons Displacement, light load 23,200 tons Displacement, light load after budging 24,500 tons Displacement, standard 27,030 tons Displacement, standard after budging 28,090 tons Displacement, full load 29,720 tons Displacement, full load after budging 33,550 tons
Number of shafts 4 Number of boilers 16 Shaft HP 200,000 HP Maximum speed 34.5 knots Maximum speed after budging 33.8 knots Most fuel efficient speed 15 knots Maximum speed with only VS drives operating 4.5 knots Bunker oil capacity 5,187 cubic meters Bunker oil capacity after budging 6,740 cubic meters Fuel consumption @ 15 knots 7800 kg/ hour Fuel consumption @ 19 knots 15,200 kg/hour Fuel consumption @ 30 knots 56,400 kg/hour Range @ 19 knots 8000 sea miles Lubricating oil capacity 222 cubic meters
Provisions 7-8 weeks Crew compliment (ship) 1720 Crew compliment (aircraft & support) 317
Weight Percentages @ full load, before budging Hull 52% Machinery 12.8% Auxiliary machinery 4.4% Armaments 5.1% Aircraft & AV gas 2.0% Fittings & equipment 2.7% Reserve feed water 1.9% Fresh water 2.2% Fuel, heating oil, lubricating oil 16.6%
* * * * * * * * Link to pictures of Graf Zeppelin under construction * * * * * * * *
* * * * * * * * Link to pictures of Graf Zeppelin during the war * * * * * * * *
Construction progressed at a decent pace on Carrier "A", considering carriers were placed at the bottom of the priority list, behind, in order, battleships, submarines, destroyers, and cruisers. By September 1939 she was 85% complete, and it was expected that the ship would be complete and ready for trials in July 1940, and ready for delivery by the winter of 1940-41. The ship was launched on December 8, 1939, and officially christened the "Graf Zeppelin." The ship's bow was modified to what the Germans called an "Atlantic Bow", intended to reduce spray over the bow at sea.
When war broke out work slowed on Graf Zeppelin, as resources and materials were diverted to u-boat construction. Work on Carrier "B" was halted entirely on September 19, 1939, and she was broken up starting in February 1940. Graf Zeppelin's 5.9 inch guns were sent off to Norway as coast defense guns, the 4.1 inch AA guns were diverted to other vessels, and the fire control system was shipped off to the Soviet Union as part of a technical exchange that included the incomplete heavy cruiser Lutzow. On April 29, 1940, the commander of the German Navy suggested that work be stopped all together, as even if the ship were completed she was worthless without guns, fire control, and aircraft.
Work was stopped, and on July 6, 1940 "Operation Zugvogel" ("migratory bird") saw the ship moved to Gotenhafen to get her away from the risk of air attack at Kiel. Graf Zeppelin began her undignified career as a floating warehouse, as her large hanger decks were used to house the Kriegsmarine's supply of hardwoods.
In June of 1941, in anticipation of the invasion of the Soviet Union and retaliatory air raids, the German Navy towed the Graf Zeppelin to Stettin, where she was moored on June 21. When no air raids occurred, the ship was towed back to Gotenhafen in November 1941.
As the world war progressed the importance of carrier aircraft was clearly demonstrated, so German naval leadership began to consider completing Graf Zeppelin. Hitler considered the issue with the Naval High Command at his headquarters on April 19, 1942. The Luftwaffe stated that they were prepared to complete 10 fighters and 22 dive bombers for the carrier. Torpedo planes, once considered to be the carriers primary weapon, were deleted from the air compliment because Hitler felt they were not needed. This decission was not without irony, as it was the British and Japanese torpedo attacks against the Italian and American fleets that had raised interest in finishing the carrier.
The Navy estimated that the hull and half the machinery could be ready for operation by June 1943, with modifications to the existing catapult system being completed at the same time. This would make the ship ready for delivery in the winter of 1943-1944. The rest of the machinery could be brought online later. A new catapult system and aircraft designed specifically for the carrier could be ready sometime in 1946, but the ship could enter service in 1944 or 45 with modified ME109 fighters and JU-87 bombers.
Hitler agreed, and on May 15, 1942 the order was given to tow the carrier back to Kiel for completion. Modifications were made to the original design, based on input from the Luftwaffe and advances in naval technology. These included:
- a heavy mast with fighter control command post was to be fitted in place of the light pole mast
- a large funnel cap was to be fitted to duct exhaust gasses up and behind the fighter command post
- the ship's command and weapons control centers were to be armored against shrapnel
- the single 20mm guns were to be replaced with quad mounts, and the ammo supply increased to 56,000 rounds
- the air compliment was increased to 40, consisting of 28 JU-87 dive bombers and 12 BF-109 fighters, with corresponding increases in pilot, flight crew, and support personnel
- larger and more wind barriers along the side of the flight deck
- an increase in bunker capacity to increase the ship's range
- budges added
- a reduction in speed to 33.8 knots was accepted due to the increased beam
This all added considerable weight, especially up high on the starboard side, so the ship was to be bulged to increase buoyancy. The port budge was standard ST 52 shipbuilding steel, while the starboard budge was thinner material, to equalize the weight gain to starboard. Both sides extended to a maximum of 7' 10", and were attached above the bilge keels, extending well above the waterline. The budges would act as underwater protection also, and be partially used as fuel oil bunkers.
The ever increasing danger of air attacks at Kiel led to a delay in transferring the ship back to her builders. The Gotenhafen division of Deutche Werke Kiel AG installed three 3.7cm twin mounts, six 20mm quad mounts, and 4 large anti-aircraft searchlights for protection during the tow. Under the cover name "Zander" and escorted by 6 patrol boats and 3 minesweepers, Graf Zeppelin was towed by three tugs to Kiel.
Arriving on December 5, 1942, Graf Zeppelin was placed in the 40,000-ton floating drydock at Deutsche Werke for the construction of her budges. Work also began to bring her inner two shafts into operation, which would allow a speed or 25-26 knots and sea trials to begin in the fall of 1943.
Work was progressing well, but on January 30, 1943, Adolf Hitler gave his famous order to discontinue work on all large navy ships, and to withdraw all current units from service. The order to stop work reached Kiel on February 2, and most of the work force left the ship. Work was allowed to continue on some systems, which would allow Graf Zeppelin to get steam up in one boiler and run the pumping system in the case of leaks. Her propellers were removed, and placed on the flight deck for storage.
On April 21, 1942, tugs took the carrier under tow and brought her to Stettin where she was moored April 23, in a branch of the Oder river with only a foot and a half of water under her keel. Nearly a year later the Graf Zeppelin was again the object of official discussion, with an eye towards getting her into service as a cargo vessel to transport a shipment of rubber from Japan, and a year after that it was asked if the ship could be used as living quarters for officers' orderlies. Both requests were denied, and Graf Zeppelin continued to sit out the war. Even the Allies ignored her, likely knowing there was no chance the ship could ever be completed, so she was spared from air attacks.
As the Red Army approached, the shutoff levers were removed from sea valves, and compartments were flooded to let the ship settle on the bottom. A ten-man demolition team was sent on board to rig depth charges and other explosives in the machinery areas, flight systems, and elevators. As the Russians entered the Stettin area on April 25, 1945, Captain Wolfgang Kahler watched the ship from the large crane at the Vulcan Shipyard. At 1800 he gave the order to ignite the charges, and thick smoke billowed out of the ship's funnel. The machinery was destroyed and part of the ship's bottom blown out: the Russians would get her as a prize, but they would have to work for her.
The Graf Zeppelin was to carry a strong gun battery, so allow her to both protect herself from ships she could not outrun, and to give her fighting power after her aircraft were launched or expended. Originally the ship was to carry eight 8-inch guns, the 20.3 cm SKC/24 in single casemate mounts. This conformed to the generally accepted armament for a heavy cruiser. Hadeler's later designs used eight 5.9 inch guns, the 15cm SKC/28 in single casemates. The final "as built" design used 16 of the same 15cm SKC/28 in casemates, but in Dopp MPLC/36 twin mounts unique to this ship.The guns shared a cradle, and the guns were 31.5 inches (800mm) apart at the center axis. The theoretical rate of fire was 8 rounds per minute, with the cartridge case weighing 18.86 lbs (8.54 kg). AP shells were available, but the normal load out for the ship would have included both base fuse and nose fuse HE rounds for a total of 115 rounds per gun, plus illumination rounds. The 15cm SKC/28 in these mounts could elevate to +35 degrees and depress to -10 degrees. Power elevation and train gear gave elevation speed of 6 degrees per second and a training rate of 8 degrees per second. The protective shield was 1.2 inches thick (30mm) and the entire mount weighed 46.86 tons.
The heavy anti-aircraft battery consisted of twelve 4.1 inch guns, the 10.5cm SKC/33 in the LC/31 dual mount. Separate cradles were used, and the guns were 26.8 inches (680mm) apart at the center axis. The theoretical rate of fire was 18 rounds per minute, with the cartridge weighing 33.3 lbs (14.7kg). AP shells were available, but the normal load out for the ship would have been comprised of HE and HE incendiary rounds totalling 400 rounds per gun plus illumination rounds. Elevation was +80 to - 8, with power elevation and train gear giving elevation speed of 10 degrees per second and train speed of 8 degrees per second. The shield was .4-.6 inches thick (10-15mm) and the mount weighed 27.38 tons.
Light AA armament consisted of twenty two 3.7cm L/80 SKC/30 automatic guns in C/30 double mounts. Separate cradles were used, and elevation was +85 to -9 degrees. The theoretical rate of fire was 30 rounds per minute, with the cartridge weighing 4.6 pounds (2.1kg). The usual round was HE tracer, with 4000 rounds per gun on board. Also included were seven 20mm L115 SKC/30 automatic guns in single C/30 mounts, firing 300 rounds per minute with 2000 rounds per gun onboard.
The main battery was powerful and would have done a light cruiser proud, but it was ultimately useless. The German designers explored the possibility of eliminating it and substituting more 4.1 inch AA guns, but this proved impossible due to their location. The AA battery consisted of mostly outdated, slow firing and slow elevating guns, and no doubt would have proved insufficient against the most modern Allied aircraft and tactics.
Graf Zeppelin's hull construction and protection corresponded to that of other large German warships of the period, and armor was on par with contemporary light cruisers. The hull was divided into 19 watertight compartments, and below the waterline the prow was in the shape of a "Taylor Pear," typical of the underwater bulbous bow of German warships. The prow was originally nearly vertical, but after launch an "Atlantic Bow" was fitted. This added more flair, and lengthened the ship by 17 feet (5.2 meters). The flighdeck and hanger decks were offset 2.6 feet (0.8 meters) to port, and the port side armor extended upwards slightly more than the starboard side, all to counteract the weight of the substantial starboard side island. As with all major German warships, the mast on the island could be laid back to allow the ship to pass under bridges along the Kiel Canal.
Side protection at the waterline was 2.3-3.1 inches (60-80mm) aft and forward of the main belt, and 4 inches (100 mm) amidships. The bow was 1 inch (25mm) thick. The flight deck was .78 inch (20mm) thick overall, thickened to 1.7 inches (45mm) around the elevators. The armored deck was of the 'turtle deck' type, 2.4 inches (60mm) on the slopes and 1.6 inches (40mm) on the horizontal, thickened to 2.4 inches (60mm) over the steering gear. Transverse bulkheads were 3.1 inches (80mm) at the ends of the ship (rib 10 and rib 218), and 2.4 inches (60mm) internally (ribs 21, 25, 56.5 and 176). The casemates were .78 inches (20mm), while the gun shields were 1.1 inch (30mm) and .4 inch (10mm) on the AA guns. The command center had 5.9 inch (150mm) protection; the chart room and gun control position .66 inch (17mm); the AA control position .55 inch (14mm); cable passages, side watch stations, and magazines .47 inch (12mm); and the gratings in the ventilation shafts and funnel uptakes were 4 inches (100mm). Armor consisted of the new Wh (Wotan hart) hard homogeneous armour for the decks and belt, and Ww (Wotan weich) soft homogeneous armour for bulkheads..
* * * * * * * * Link to cross section showing armor thickness * * * * * * * *
Graf Zeppelin never saw open water except under tow, so there is no data on her seakeeping, handling, or ability or maintain a stable flight deck. Her armor protection included an armored flight deck, like contemporary British carriers, out of concern for making her better able to withstand attack from land based aircraft. The side belt compared favorably to many contemporary light cruisers, though the curved 'turtle deck' armored deck design had been abandoned by other navies by then, though it was arguably well suited for close range protection against small caliber fire. Subdivision and machinery compartmentalization was equal to other major German warships of the time. The double bottom only covered the area below and between the bilge keels, where it did not offer protection against torpedoes: like a contemporary cruiser, there was no attempt to include a multi-layered torpedo defense system. The addition of external budges added greatly to the ship's underwater protection.
Graf Zeppelin had four shafts, each with a four bladed propellers 14.4 feet (4.4 meters) across. Each shaft was powered by turbines built by Brown, Boveri & Co, producing 50,000 HP each for a total of 200,000 HP. At the time of her design there were the most powerful turbines ever built for a European ship. The two turbines powering the inner shafts shared a turbine room, while the ones on the outer shafts were separated into their own spaces. Steam was produced by 16 La Mont water-tube boilers operating at 75 atmospheres and 840 degrees F (450 degrees C). The boilers were separated into four boiler rooms. At 300 revolutions per minute, the plant was expected to drive the ship to 34.5 knots as designed. The propulsion plant weighed in at 3,850 tons, giving a power to weight ratio of about 42.4 pounds (19.25 kg) per horsepower.
Electrical power was provided by a variety of systems. 5 diesel generators of 350 kW each, 5 turbo generators of 460 kW each, and 1 turbogenerator of 230 kW with an attached 200 kVa alternating current generator were provided. Total output was 4,280 kW at 220 volts.
In addition to her main propulsion system, Graf Zeppelin was fitted with two Voith-Schneider steering/ propulsion systems. Common today on tugboats and service craft because of their ability to direct thrust in any direction, they were rather new at the time. The systems were electric of 330 kW each, mounted one in front of the other at the forward part of the ship. They were contained in pods recessed into vertical shafts, to be extended down into the water when needed, and could move the ship forward or backwards at a speed of 4.5 knots on their own in calm water with no wind. But propulsion was not their primary purpose- the Graf Zeppelin was a huge ship with huge slab sides, which would be under a lot of pressure in a cross wind. The speed limit on the narrow Kiel Canal was 8 knots, and at this speed Graf Zeppelin's rudder force would be insufficient to keep the ship from being blown into the wall of the canal on a windy day. So the Voith-Schneider systems were included to keep the ship under control in the canal.
* * * * * * * * Link to Voith-Schneider picture * * * * Link to Voith-Schneider animation * * * * * * * *
The powerful machinery in the Graf Zeppelin was impressive on paper, though the experience of German heavy cruisers during the war cast doubts as to its reliability, and fuel consumption was excessive at high speed. The Voith-Schneider system was quite advanced for the day, and certainly would have made many an Allied carrier commander jealous of the Graf Zeppelin's maneuverability in port.
The Luftwaffe was buying every aircraft that Germany's industry could put out, so manufacturers saw no profit in designing and building special-purpose aircraft in small numbers for this lone carrier. Supplying spare aircraft and parts for unique designs would have been difficult also, so it was decided to use modified versions of aircraft already in production. Modifications included folding wings to save space, tail hooks for arresting gear, and the reinforcement of landing gear and frames to stand up to the forces of arrested landings. Only in 1942, after the value of carrier aircraft had been clearly demonstrated, was serious consideration given to carrier-specific designs.
The ship was designed with a compliment of 43 aircraft in mind, though this compliment was reduced as larger aircraft were selected for the ship.
Original plans called for a multi-purpose aircraft for scouting and torpedo bombing. These were the heart of the air wing, as scouting and torpedo attack were considered to be the aircraft's main mission. Specifications were sent out to Fieseler and Arado, and each delivered test aircraft as early as 1937-38. Both were biplanes, the Fieseler 167 and the Arado 195. Both designs were tested, but the multipurpose aircraft was ultimately eliminated from the air group, as neither design had acceptable performance.
* * * * * * * * Link to Feisler 167 picture * * * * Link to Arado 195 picture * * * * * * * *
For a fighter, the existing Arado 68 biplane fighter was selected, the modified version to carry the designation "Arado 197". Flight tests were carried out throughout 1938 and 1939, but the plane was ultimately rejected due to its top speed of only 248 MPH (400 KPH).
* * * * * * * * Link to Arado 68 picture * * * * Link to Arado 197 picture * * * * * * * *
The Messerschmitt ME 109 E, already fully developed for the Luftwaffe, was selected to replace the Arado 197. The modified version was the ME 109T, and 10 were built by Messerschmitt. Eventually another 60 would be built by Fieseler under contract. The monoplane fighter was one of the best in the early stages of the war. The "T" version (T for Träger, carrier) had folding wings, an attachment for the catapult carriage, an arresting hook, and a wingspan increased by two feet to add lift at low speed. Powered by a Daimler Benz DB 601N engine, the "T" model carried two machine guns and one cannon. Work was being done on an improved model when carrier construction was halted, and all ME 109Ts were converted back into regular fighters, all being lost by 1944. When work resumed on the carrier design work on an improved ME 109T resumed, but the design was not finished and no aircraft were produced.
* * * * * * * * Link to ME 109T picture * * * * * * * *
For dive bombing the Junkers 87 was selected, the modified version designated the JU 87 C. Five test planes were constructed and tested by the Travemunde Testing Institute, which tested the other aircraft as well. Folding wings, arresting gear, and attachments for the catapult were added. The main landing gear was modified also- being fixed, it made water landings dangerous, so the "C" model could jettison the main gear in case of emergency. All five were converted back into regular JU 87s when work on the Graf Zeppelin stopped. When work resumed on the carrier, a converted model based on the better performing JU 87 D was planned, but none were constructed.
* * * * * * * * Link to JU 87 C pictures (3) * * * * * * * *
The aircraft originally selected for the carrier were second-rate biplanes, a reflection of the low priority the Luftwaffe gave to equipping the ship. The ultimate selection of the ME 109 and JU 87 gave the ship a decent air group by 1939-40 standards, but both aircraft types would have been obsolete and outclassed by Allied naval aircraft by the time the ship was completed. Without a torpedo plane the striking power of the air wing was limited against enemy warships.
The use of land based aircraft on the carrier, the uncertainty of what aircraft the ship would ultimately carry, and the desire to launch aircraft as quickly as possible led the design team to include two bow catapults rather than have the aircraft fly off the flight deck on their own. The catapults were compressed air powered, each having two tracks 9.25 inches apart and being 77 feet (23.5 meters) long. The catapults used launching sleds, which would accelerate the aircraft forward, then be caught in a complicated catching mechanism that would slide them over on stages, drop them down below the flight deck, and return them along rails to elevators that would return them to the launch position. Each catapult had a cycle time of one minute, so by alternating them one aircraft could be launched every 30 seconds.
* * * * * * * * Link to catapult system drawing * * * * * * *
The arresting system consisted of four cables, located 86, 146, 178, and 216 feet forward of the edge of the flight deck. Two wind protectors could be erected, each being 12 feet tall and 42 feet long. The flight deck was serviced by three center line lifts, bringing aircraft to and from the two hanger decks. The hanger decks were a touch over 21 feet tall, and were up to 51 feet wide. The upper hanger was 606 feet long, and the lower hanger 558 feet long. The original design called for the upper hanger to hold 13 JU 87S aircraft forward and 8-10 Arado 197 aircraft aft of the aft elevator. The lower deck was to hold 10 Fi 167s forward and 8 Fi 167s aft.
The ship was to carry 150-200 tons of aviation fuel for her aircraft, along with armament and spare parts.
Graf Zeppelin never operated any aircraft, and the catapult system was never finalized and modified for the chosen aircraft, so there is no way to know if the flight systems would have been reliable and efficient. The German carrier would have carried far fewer aircraft than US carriers of similar tonnage, and somewhat fewer than British carriers with armored flight decks. This decrease in aircraft compliment is understandable considering the amount of weight devoted to guns and armor for the ship, and the use of improvised land-based aircraft rather than specialized aircraft.
* * * * * * * * Link to pictures of Graf Zeppelin post-war * * * * * * * *
Russian salvage experts worked on sealing the Graf Zeppelin's hull until March of 1946, when they were able to pump her dry and float her. The hulk was towed to Swinemunde, where repairs continued. Acting again as a floating warehouse, the ship's hanger decks were loaded with war booty and railroad rolling stock to be returned to the Soviet Union. In late August 1947 she was designated PO-101 and taken under tow by tugs, bound for Leningrad. Sometime in early September the ship was forced off course in a storm, and into a minefield off Finnbusen. She struck at least one mine, leading many reference works to claim she sank. But the tugs regained control and the damaged hulk made it to Leningrad. Between the German sabotage and the minefield, she was well past the point of repair. The ship was unloaded, and stripped of anything usable. Sometime in 1949 she was towed out to sea for use in weapons tests. Two 1000 kg bombs, two 500 kg bombs, three 250 kg bombs, five 100 kg bombs and four 92 kg charges detonated on the flight deck or hanger deck, presumably to test the effect of these weapons on aircraft carriers, valuable information to have with the Cold War blossoming and the US Navy now a potential enemy. Then dive bombers used her for practice, scoring six hits, and the torpedo boat OE-503 and destroyer Slavniy each put a 53.3 cm torpedo into her. The battered hulk finally sank in 280 feet of water, 38 miles north of Gdansk, her exact location not being recorded.
On July 12, 2006, a ship belonging to the Polish oil company Petrobaltic was surveying the bottom of the Baltic for a pipeline. R/V St. Barbara reported encountering an unknown wreck on sonar, approximately 850 feet long, and shaped like an aircraft carrier. Two weeks later the Polish Navy's survey ship ORP Arctowski began an exploration of the wreck, confirming that it was without a doubt the Graf Zeppelin.
* * * * * * * * Link to pictures of the Graf Zeppelin being sunk * * * * * * * * * * * * * * * * Link to pictures of the wreck of the ex-Graf Zeppelin * * * * * * * *
Graf Zeppelin in general does not compare well with contemporary carriers from other nations, a product of her long development time and German inexperience with the type. She was certainly better than the first carrier offerings from other nations, being larger and faster than the inadaquate first generation carriers like USS Langley. Other nations developed carriers as scouting and support vessels for their battlelines, but at the time Germany had no battleline to support. Graz Zeppelin's strong gun battery (especially as designed with 8-inch guns) and armor scheme indicate that initially she was considered a cruiser that operated aircraft, with her guns being her primary weapons. As the design developed and decent aircraft were found for her it became obvious that the aircraft were her primary weapon, but by then it was too late to radically change the design. It would have been interesting to see how the ship would have been modified after entering service, with the casemate guns no doubt being removed and the AA battery improved.
While the design and construction of Graf Zeppelin ultimately proved to be a wasted effort, and the resulting ship was not in itself terribly impressive, the remarkable thing is that she was built at all. In a time when Germany had no real navy to speak of, and warships and aircraft development had been hamstrung by the Treaty of Versailles, the Germans were able to design, engineer, and ultimately construct an aircraft carrier from scratch, using many unique solutions. This is a feat many nations are still struggling with today- the list of nations that have designed and constructed their own carriers for conventional aircraft is a short one.