Last photograph of Graf Zeppelin towed from Swinocijscie Poland to Leningrad. April 17. 1947.
In April 1945, Soviet troops found the carrier’s artillery had been dismantled, the installation of fire control equipment had not been finished and the electrical installations partially installed as well as the flight equipment. There was a complete engine room and the power station was fully operational. Among the explosives, ten depth charges had been set off in the engine room. Water had penetrated through small blow-holes, cracks and leakages and the ship settled on the bottom in water seven meters deep. Seepage was so slow the water in the engine room was lower than that outside the hull. By 17th August 1945 the ship had been examined by teams of the 77th Emergency Rescue Unit. The carrier lay on the bottom with only half a degree of list to starboard. On the starboard were 36 holes up 1.0 X 1.0 meters made by shells and fragments. All the turbines, boilers and power plants had been blown up damaging the nearby watertight bulkheads. One .8 x .3 meter hole had been blown in the underwater part of the ship along with a .3 meter crack. The propellers had been dismantled and placed on the flight deck to minimize electrochemical corrosion of the hull. The aircraft elevators had been blown up as well. The ship was raised by simply sealing the underwater hole and crack and pumping out the water. Ten longitudinal and twelve transverse bulkheads had to be sealed to give the ship the necessary buoyancy. Cracks above the waterline and portholes were sealed with wielded metal sheets. Due to extensive damage and time pressures damage to ship’s deck were not mended. After the repairs were completed the ship was towed to Świnoujście, the former Kriegsmarine base known as Swinemunde. On 19th August the hulk was included in the Soviet Navy as a spoil of war. At the Potsdam Conference (17th July until 2nd August) the first agreement was reached on how to dispose of captured German surface vessels. On 23rd January 1946 an Anglo-American-Soviet committee was formed to deal with these matters. All combat and auxiliary vessels were divided into three categories A, B or C. The Graf Zeppelin was given to the Soviets by lot and came under category C – ships sunk, damaged or unfinished that required over six months of repairs using the resources of German shipyards. It was the recommendation of the committee that category C ships should be scuttled in deep water or dismantled by a given date. Admiral Kuzniecov requested to repair the Graf Zeppelin for use as an experimental platform for the construction of Soviet aircraft carriers. Initially he was given approval for the Baltic shipyard in Leningrad to carry out the necessary repairs; however the authorities chose the simpler option of complying with the terms of the allied agreement. On March 17th 1947 a resolution was passed that all category C vessels were to be destroyed in 1947. The command of the Soviet Navy had managed to convince the government to run durability tests on the vessels.
From 2nd February 1947 the Graf Zeppelin was classified as experimental platform PB-101. The destruction was to be carried out in a manner that allowed the collection of experimental data and experiences. A special committee head by Vice-Admiral Rall was formed and ordered to sink the carrier while testing its resistance to aerial bombs, artillery shells, and torpedoes in two variants, static and dynamic. Static meaning that the munitions would be placed in the ship and detonated and dynamic that they would be delivered by simulated attacks. The detonation of mines at various depths and distances from the ship was also considered. Between the tests teams of scientists would be sent aboard to assess the effects of the explosions. They were allowed to conduct minor repairs to stop the ship from sinking too soon.
At 2.45 pm on 14th August 1947 PB-101, as she was now known was pulled out onto the out roadstead of Świnoujście from where she was escorted by various vessels to the five mile square designated as the test area. Due to draining of three starboard rooms in the bulges she had a 3 degree list to port. When she arrived on the evening 15/16th August if was found that she could not be anchored. One of the main anchor chain links failed and the light kedge anchor could not prevent the ship from drifting. This was to affect the final outcome of the testing.
The first tests were carried out on the morning of 16th August. First a FAB-1000 bomb was exploded in the funnel along with three FAB-100 bombs and two 180 mm shells set under the flight deck. For the second test a FAB-1000 bomb was detonated on the flight deck. For the third a FAB-250 was set off on the flight deck and two 180 mm shells on the upper hangar deck. For the forth a FAB-500 over the flight deck set on a 2.7 meter high tripod, a FAB-250 on the upper hangar deck, another on the flight deck and a FAB-100 on the C deck. The fifth and last of the series, a FAB-500 and FAB-100 detonated on the flight deck with part of the bombs set deep in holes cut in the deck to simulate penetration.
The funnel was ripped open down to the flight deck but the island was not damaged, with the shockwave failing to deform the smoke ducts. No increase in pressure in the boilers was reported and on the armoured gratings an intact spider’s web was found. Of the three FAB-100 bombs detonated on the flight deck the most damaging was the one not set in the deck. The shockwaves of those set in deck were directed down into the hangar. The 180 mm shells caused various damage, the most effective being mixed armour piercing high explosive.
After the first series of tests an air raid was carried out on the ship by 39 aircraft from the 12th Guards Mine Torpedo Division and 25 Pe-2 dive bombers. On the day of the test there were only 100 P-50 exercise bombs available in the entire 4th Fleet instead of the 156 required. Therefore only 24 Pe-2 crews could perform the bombardment. Two nine plane flights dropped their payloads on the leader’s signal, the rest individually. A white 20 x 20 meter cross had be painted on the flight deck with arms 5 meters wide. The first group dropped 28 bombs from a height of 2070 meters, the second 36 from about the same height and the third attack carried out individually another 24 bombs. Three aircraft were forced to emergency dump their ordnance. The effects of the attack on what was a ‘sitting duck’ were farcical. Of the 100 bombs dropped only six hit the target, and there were only five marks on the flight deck. (Soviet pilots claimed there were eleven hits, some of the bombs having struck already damaged areas.) The test failed to give any useful information. The P-50 bombs were too small causing 5-10 cm dents in the flight deck and blew a hole about one meter in diameter in the starboard bulge. The pilots complained about poor visibility.
Another series of static explosions followed. After the forth series the entire island was wiped out and the upper hanger seriously damaged. The effect of the fifth series was the most spectacular. A FAB-550 bomb on the flight deck blew a three meter hole and a FAB-100 bomb in the hanger demolished all the light walls and destroyed the equipment. That concluded the static tests and preparations for the testing of underwater munitions where begun. On 17th August the weather bean to worsen and the carrier started to drift towards the shoals. There was the possibility that the ship would drift into waters too shallow to sink her. Rall decided to abandon the testing and finish off the carrier with torpedoes. The planed bombardment by cruisers had been cancelled because of an accident in one of the main turrets of the Molotov. The usage of the 180mm artillery was banned in the entire Soviet Navy for the year 1947. Three torpedo boats and the destroyers Slavny, Srogy, and Stroiny were summoned. The torpedo boats arrived first. The first run by TK-248 was unsuccessful, the torpedo passing under the carrier’s keel. After 15 minutes a torpedo fired by TK-503 hit the starboard side near frame 130. The explosion destroyed the bulge but the armoured belt remained unscathed. After an hour the destroyers arrived and the Slavny hit again the starboard side near frame 180 where there was no bulge. The carrier began to list to the twice damaged starboard. After 15 minutes the list reached 25 degrees, and the ship started to trim to bow. After another eight minutes the Graf Zeppelin with a 90 degree list 25 degree trim to bow slipped below the surface. The date was 18th August 1947.
The results of the tests were kept secret and the allies only informed that she had been sunk. The gap between the summer of 1945 when she was raised and March 1947 when her fate was decided remains a mystery. The German Admiral Ruge claimed in a book that the carrier capsized while being towed from Stettin to a Russian port due to the stowage of steel sheets on the flight deck According to gossip circulating in the Baltic Fleet published by Marek Twardowski in a magazine article, in 1946 the ship was towed to a Leningrad shipyard to be prepared for service. The authorities found this a welcome occasion for the transport of heavy loot which was placed on the flight deck because the damaged elevators prevented the stowage in the hangers. Placing a heavy weight on the flight deck made the ship unstable and she capsized in the shallow fairway. Most of the goods from the flight deck fell in the water, whilst those stored below caused serious damage to the bulkheads and braces. Raising the ship was not difficult but she was no longer suitable for reconstruction and had to be sunk to cover the accident. This supports the account of Ruge but is most probably untrue.