Part Ten
The Five Kreigsmarine Aircraft Carriers 1934-45
1. CVT/E Oswald Boelcke
Ironically the first Kreigsmarine carrier would be its longest serving and sole carrier to survive the war before its scrapping in 1955. Acquired to provide an aviation training platform in 1934 it was a basic conversion of the 10,000-ton merchant vessel Hansel for this role. As completed it was an unarmed diesel-powered vessel without armor and fitted with a wooden flight deck, two elevators and a catapult. Completed initially without any ordnance handling facilities or aviation fuel storage, it would later have these supplemented to a limited degree. Lacking the endurance of other small carriers, it would be adequate for operations in the confined waters of the Baltic. As the navy’s first true aircraft carrier it was not actually commissioned into the Kreigsmarine until 1935 after the signing of the Anglo-German naval treaty and be named Oswald Boelcke after the famous WW1 fighter ace.
It would be continuously employed as the Navy training carrier for the majority of its service and survive WW2. Later fitted with a light anti-aircraft armament and able to carry up to 22 aircraft it was similar to other small training carriers of this period. Due to its basic design and small air group, it operated entirely in Baltic waters. With no other navy carriers and the deteriorating situation on the Eastern Front from late 1944 onward it would be active in limited operational roles providing aircover and support as required, and be one of the remaining Kreigsmarine vessels evacuating civilians from East Prussia. Uniquely, in one of his few actions as Fuhrer after Hitler’s death, Admiral Doenitz would ‘sell’ it to Finland for 100RM two days before VE day. This ‘voluntarily sale/transfer’ would see it remain in the Finnish Navy continuing as a limited training carrier until its disposal and scrapping in 1955.
2. CV Graf Zeppelin
The Graf Zeppelin nearing completion late 1938. (Note the twin 5.9-inch medium calibre mounts that would be deleted in her following sister ship Werner Voss)
One of the two specifically designed large carriers for the navy, it was the sole operational carrier when war broke out in 1939. Despite some less-than-optimal design aspects upon completion, at 33,000tons with good speed and armor and capable of carrying 42 aircraft it represented a capable platform for its intended role. Named after Graf (Count) Ferdinand von Zeppelin, the ship was launched on 8 December 1936, and due to shifting construction priorities its completion was delayed until September 1939. Working up in the Baltic it missed the disastrous losses of the Norway campaign, and first operational deployment was its involvement in Operation Rheinubung in the North Atlantic in May 1941.
Incorporating the four Kriegsmarine large surface units available at the time, battleships Bismarck and Scharnhorst, heavy cruiser Prinz Eugen along with the Graf Zeppelin. The planned intent was to break out into the North Atlantic convoy routes causing damage and disruption to the British convoys, before returning home. The Graf Zeppelin was to accompany the force providing air cover and to engage detected RN covering forces in the Denmark Straight to assist the breakout of the other heavy units. Once this was achieved the Graf Zeppelin was to withdraw to Norway.
Unfortunately, due to signals intelligence and aerial recon, the British Admiralty was alerted, and the majority of the Home Fleet deployed to counter this operation. The resulting Battle of the Denmark Straight is well known. Though successful in sinking both the aircraft carrier Glorious and heavy cruiser Suffolk as intended, the Graf Zeppelin would be sunk by the counter strikes of the three Home Fleet Carriers concentrated to oppose the German breakout. Of the other major German surface vessels, only the Prinz Eugen would survive to return to Norway.
Photo of the last moments of the Graf Zeppelin, sinking in the battle of the Denmark Straights.
Sonar image of the surprisingly intact and upright wreck of the Graf Zeppelin on the Atlantic Ocean Floor 2016.
3. CV Werner Voss
The sister ship of the earlier Graf Zeppelin was one of the deferred Kreigsmarine construction projects of 1937. (2) Postponement enabled several earlier design issues of her earlier sister ship to be corrected and design changes incorporated when work resumed briefly in late 1939. The 5.9-in weapons and magazines where deleted, replaced by additional sponson mounted 4.1-inch guns and AA mounts. This removal enabled an enlarged and improved aviation fuel storage system and greater hangar for additional aircraft. Beyond the obvious replaced medium mounts with AA guns, other visual cues differentiated the two sister ships. A curved ‘Atlantic’ bow for improved sea keeping a longer lower bridge structure and broader funnel without cap being the obvious visual changes.
1942 and the 85% complete hull of the Werner Voss being towed into dock to finish the delayed fitting out process.
Work would eventually resume after the failure of Operation Rheinubung late 1941. Despite several machinery issues which delayed its workup the Werner Voss was included in the planning for Operations Silver Gull, the naval portion of the attack to secure the Kola Peninsula in 1942, with other major Kreigsmarine combatants in April 1942. The concentration of this force was detected by the British, unaware of the actual operational plan and fearing a repeat of the earlier Operation Rheinubung to break out into the convoy routes of the North Atlantic, a maximum effort raid was mounted by RAF Bomber Command against the carriers and cruisers concentrated in Faettenfjord Norway. On the evening of 28/29 April 1942 some 330 Lancasters and Halifaxes of Bomber Command conducted a major attack on this anchorage.
The capsized hull of the Werner Voss in Faettenfjord, Norway undergoing salvage work in 1948. |
Unbeknownst to the British the majority of the force had departed the prior afternoon to the raid, moving to Tromso in far northern Norway in preparation for the upcoming offensive. Unfortunately, the Werner Voss had suffered a significant engineering casualty during the move to Norway, and the resulting delay led to it remaining behind and being the sole vessel in the anchorage when raided. As such it bore the full brunt of the attack. It is assessed that it was struck by a least four 1000lb bombs and several smaller bombs causing catastrophic damage. Set on fire, flooding rapidly overwhelmed the ship and it capsized in shallow water, with the upturned hull remaining visible. (3)
The majority of the Werner Voss’s air group survived having earlier been flown off initially upon arrival. They would subsequently participate in Operation Silver Gull as part of the land-based MFK component of Luftflotte 5. They would remain in Norway and continue to operate in Arctic waters until the MFK component was withdrawn to Germany in late 1944. The wreck of Werner Voss remained in place until after the war, with salvage work lasting from 1948 until 1952.
4. CVL Lutzow. (4)
Lutzow was the last of the six P-class cruiser hulls laid down after 1930 and was the oldest of the three 1937 deferred hulls. The initial design was resource intensive and construction delays resulted after vessels four and five were enlarged and completed using Lutzow’s turrets as the Scharnhorst-class battleships. This, included with the Nazi Parties assumption of power and amended construction priorities, resulted in work halting on the Lutzow with the hull only 80% complete in 1937. Work would only resume in 1941 and was completed as a very austere and simple wooden-decked carrier capable of operating 38 aircraft in 1942. After a brief work up in the Baltic it was one of the three carriers assigned to Operation Silver Gull in April 1942.
The 80% complete Lutzow being fitted with a wooden flight deck 1942 as an austere carrier conversion.
Despite its austere layout, with its longer hull and high speed it was to prove very effective in this operation, with its air group contributing to the sinking of both major vessels of the Soviet Northern Fleet, Archangelsk and Murmansk along with other shipping in the opening phases and providing air cover for the successful occupation of the Kola Peninsula. With its objectives concluded, it and the other surface vessels involved would be withdrawn back to the Baltic in late May.
Anticipating this withdrawal the RN mounted a major operation to interdict the withdrawing vessels, concentrating over a dozen submarines in Norway waters and the North Sea, and mounting a large aerial mining campaign on the approaches to Wilhelmshaven. Despite the high transit speed and heavy escort, the British submarine HMS Spearfish attacked the ship on 29 April and scored a single serious hit. The torpedo hit the Lützow's stern quarter, blowing off one shaft and causing major flooding. Nevertheless, it was still able to proceed at over 10 knots and reached the Jade River Estuary shortly before dawn, where it struck an aerial mine causing further flooding and major damage. But for the availability of tugs and close proximity of the port then it probably would have been lost.
Due to the extent and significance of the damage the ship would remain in dockyards hands for repairs, which lasted for nearly a year. During her time in drydock and on the dockside in Kiel, Lützow was twice specifically targeted by large British bombing raids, on both occasions being hit with 500-lb GP bombs. The resultant damage added to repair delays, and it would not be until the second half of 1943 that the Lutzow was again operational.
For the remainder of her service the Lutzow would remain in the Baltic supporting naval and land force operations as the Eastern Front situation deteriorated. On 18 December 1944 Lützow was in Gotenhafen when the RAF executed a major raid targeting the port. Many ships were sunk in the harbor and a single bomb struck the very bow of the ship, but several near misses inflicted considerable underwater damage. Moved to the port of Swinemünde to receive temporary repairs. On 16 April 1945, specifically targeted by bombers from 617 ("Dambusters") squadron carrying 1000-pound bombs and the super-heavy Tallboy bomb. Three 1000-pound bombs hit the ship and of the Seven Tallboys dropped, one exploded between the ship and the shore and tore a one-by-ten-meter hole in hull, while a second penetrated right through the ship, detonating below it and breaking its back just forward of the forward hanger. The front portion broke off and sank rapidly, while the rear portion was only prevented from capsizing by her superstructure hitting the shore. Most of the lower decks were flooded but despite sinking, the water was shallow enough that her main deck was still partially above water. With Soviet forces approaching her crew rigged scuttling charges and destroyed the hull in Kaiserfahrt canal on 23 April 1945. The remnants of the ship were raised from the shallow water in September 1947 and broke her up for scrap in 1948–1949.
Reco. photo of the Lutzow in Moene Canal Sweenemunde, which would result in the Tallboy raid and sinking.
5. CVL Seydlitz (5)
Seydlitz was the second navy heavy cruiser of the Prinz Eugen class, but its completion was stopped in 1938 95 percent complete. The unfinished ship remained pier-side in the shipyard until 1941, when Hitler allows its completion as an aircraft carrier instead. Following Operation Rheinubung Hitler’s order to scrap incomplete vessels reflected his loss of faith in the Kreigsmarine. Only with Goring’s support was this altered for the affected vessels to be completed as aircraft carriers.
Photo of the 95% complete Seydlitz in dock, shortly before commencing conversion to aircraft carrier 1942.
With this, the conversion work began on Seydlitz. Despite the ship being approximately 95 percent complete, and only requiring a very short period to become fully operational by installing her anti-aircraft armament, masts, cranes, and aircraft catapult, the far slower rebuilding work to become a carrier was commenced. Hitler’s decision now required the majority of the superstructure be cut away, to prepare for the installation of a flight deck and an aircraft hangar. In total, over 2,400 tons of material from the ship was removed, replaced by an unarmoured wooden flight deck, hanger, elevators, catapults and arresting gear before the conversion was completed. The work included anti-aircraft armament, island superstructure and reworked funnel installed on the starboard side, with a tall, tubular mast on the forward end of the island, and a minimum air complement was of at least 20 aircraft. Late in the process this was reworked to allow installation of radar and to reduce topweight, a relocated shorter mast incorporated and some 4.1-inch mounts deleted. Her propulsion system, already installed remained the same, providing a very high performance, but all this additional work took time and the ship and crew only had a short workup period in the Baltic before transferring in April 1942 in preparation for the upcoming operation in northern Norway against the Soviet Union.
Photo showing some of the 2,400 tons of upper works removed to facilitate the conversion.
Despite the loss of the Werner Voss before the commencement of the offensive, the result was an unqualified operational success for the new carrier arm. Using a deck park and effectively operating 28 aircraft, the Seydlitz and Lutzow air groups together have a major impact. The initial attack on Murmansk harbor would torpedo and sink the light cruiser Murmansk (ex-USN Milwaukee) two northern fleet destroyers and two icebreakers and successfully cover the Luftwaffe parachute assault at Severomorsk. This would be followed by further raids on Archangelsk sinking additional vessels including another destroyer and merchant shipping and finishing off the damaged battleship Archangelsk (ex HMS Royal Sovereign) torpedoed by U-477 when attempting to interfere with the attacks. At the end of May, with the Kola Peninsula and Murmansk occupied and all operational objective achieved, both carriers and other surface ships were withdrawn south to return to the security of the Baltic.
Unfortunately for the Kreigsmarine the RN had sufficient time to mount a major operation to intercept the returning vessels. Though avoiding air interception, a major aerial mining operation had been mounted and nearly a dozen allied submarines deployed in Norwegian waters and the North Sea to engage the withdrawing forces. These measures proved effective and despite a large escort and transiting the gap at night and high speed of 28 knots to avoid submarines, such was the concentration of forces that despite this, three of the ships would be successfully engaged in the attempted crossing on the night of 27 May 1942. Though badly damaged by torpedo attack and mining, both Lutzow and Prinz Eugen would survive and successfully reach Wilhelmshaven to undergo extended time in docks. The Seydlitz was less fortunate. The submarine HMS Triton (6) would launch a full salvo of eight torpedoes at the Seydlitz. Four of these would hit the port side, causing catastrophic damage and the Seydlitz would rapidly capsize and sink in less than 20 minutes taking nearly 900 of her crew with her. This was to mark the unfortunate end of the Kreigsmarine sole successful operational deployment of its carrier arm, and again highlighted Raeder’s pre-war prediction of heavy losses in challenging the power of the RN in the confined waters of the North Sea.
Conclusion
Constrained by the internal dynamics of the Nazi system and industrial restrictions in competition with the other services in pre-war Germany, the Kreigsmarine was never able to effectively build towards any form of desired force structure for the conflict it faced. Decisions made by Hitler in 1937-38 meant the Kreigsmarine lost the freedom to adapt and develop more effective force structures in the immediate lead up to the war. Lacking the means to project force resulted in it having no real realistic strategic role in which it could be employed beyond the European theatre. In the pre-war period, Naval aviation, carrier and submarine construction in particular lagged behind what was required, with the result that when war broke out there was little scope for its potential to be developed. Committing its sole operational carrier in Operation Rheinubung, invited the defeat in detail that occurred when the RN was able to concentrate sufficient force to overwhelm it in isolation. That this induced the Kreigsmarine to finalize several incomplete hulls as basic carriers as a result, and the relative effectiveness of employing them together on the one occasion it occurred, indicates the unrealized potential of that arm had more carriers been available earlier.
While most historians and analysts believe that it would have been unlikely for Germany to ultimately succeed in effectively targeting the British maritime trade. It is often now conjectured that multiple carriers correctly employed in support of existing surface assets in the Atlantic (particularly if in conjunction with the possible variations of Plan I, the occupation of Iceland and the Faroes), the potential existed for the Battle for the Atlantic to have been far more costly and to last longer while making far greater demands upon the RN resources than actually occurred. Even maintenance of a significant force in being in Norway would have required matching forces being retained in the home waters in Britain. Had this occurred it would have denied Britain much of the strategic freedom to release many of its major assets to other theatres as occurred from 1942 onward. Without such a buildup it is highly possibly that events in the Mediterranean and opening phases of the Pacific campaign could have developed far less favorably for the Allies than was to actually occur.
The eventual ineffectiveness of the Kreigsmarine employment in WW2 can be directly attributed to decisions made by Adolf Hitler in the lead up to War. This would highlight the failure of the Kreigsmarine to have an effective force structure for the struggle it faced, particularly carriers and submarines, that would have forced the RN and Britain to prioritize operations in home waters to a far greater degree, and ultimately achieve a greater strategic impact than that which resulted. This assessment applies to the MFK as a component part of the Kreigsmarine and is a reflection of this fundamental fact. While well-equipped and trained, the ultimate weakness of the Kreigsmarine lay in the system that developed it, and its failure to develop the force levels necessary to successfully prosecute effective naval operations against the greater capabilities of Great Britain and the Allies.
1. Ordered as Flugzeugträger A, and launched December 1938 Graf Zeppelin was incomplete in April 1940, when work on her was suspended. In May 1942, with Hitler's authorization, work resumed on the carrier. By late January 1943 Hitler had become so disenchanted with the poor performance of the Kriegsmarine surface fleet, he ordered its larger ships taken out of service and scrapped. Construction on the carrier ended in February 1943 and Graf Zeppelin languished for the next two years in various Baltic ports before being scuttled off Stettin in April 1945 ahead of the advancing Red Army.
2. IRL the sister ship was laid down as Flugzeugträger B in 1938 but work was halted on 19 September 1939 with the outbreak of hostilities. Priority now shifted to U-boat construction and the partially completed hull, still unnamed, sat rusting on its slipway until February 1940, when it was broken up and scrapped.
3. This is based on the IRL Bomber Command attacks on the battleship Tirpitz anchored in Faettenfjord on successive nights 27/28 April 1942. Due to bad weather and navigation issues the majority of the bombers were unable to locate the target and the Tirpitz escaped unscathed for the loss of seven bombers.
4. This is an amalgam of the two Kreigsmarine vessels IRL. The first Lützow was the 5th and final Admiral Hipper class heavy cruiser. was never completed. Launched in July 1939, the vessel was still incomplete when sold to the Soviet Union in April 1940. About 80% complete when towed to Leningrad where it was renamed Petropavlovsk in September 1940. Still unfinished when Germany invaded the Soviet Union in June 1941, the ship was sunk in April 1942, and later raised in September, before being eventually broken up for scrap sometime between 1953 and 1961. With the name available the 1st Panzerschiffe Deutschland was renamed Lutzow at Hitlers direction in 1940 and narrative events reflect incidents in its career. It was torpedoed and severely damaged by HMS Spearfish in April 1940, damaged twice by air attack, and in April 1945, RAF Lancasters carrying Tallboy bombs successfully hit the ship moored in the Kaiserfahrt canal, Swinemünde. Hit or near missed the ship was so so damaged it was only prevented from capsizing by her superstructure hitting the shore. The wreck was later broken up during the 1940s.
5. The IRL Seydlitz was the 4th Admiral Hipper Class cruiser launched in January 1939. The outbreak of World War II slowed her construction and fitting-out work and by the time work stopped completely in June 1942, the ship was approximately 95 percent complete with only her anti-aircraft armament, masts, cranes, and aircraft catapult left to be installed. At this point the Kriegsmarine decided to pursue aircraft carriers over surface combatants and the Seydlitz despite its advanced state was chosen for conversion. Renamed Weser, the converted ship was to have had a complement of at least twenty aircraft. The majority of the superstructure was cut away, with the exception of the funnel, to prepare for the installation of a flight deck and an aircraft hangar. In total, some 2,400 tons of material was removed before conversion work ceased in June 1943. The incomplete, hull was seized by the Soviets in 1945 and later broken up for scrap. The conversion design as presented in part Nine of this thread is largely as IRL, but with minor modification ITTL. The tall tubular mast on the forward end of the island is shortened and relocated to take radar installation and the 4.1-in mounts reduced by one.
6. During the night of 8 April 1940, Triton encountered the German cruisers Blücher and Lützow but inexplicable missed with a full salvo of ten torpedoes fired at close range.
