I'm beginning to draft an alternate history of naval aviation (carrier-based), one in which Germany plays a leading role. The initial draft of the first few chapters is below. Not all of the original MS Word formating and no illustrations made the transition, sorry:
Comments and suggestions from those more informed than I are more than welcome.
Preface – 30 May 1914
Airship L-3 had just passed over Cuxhaven into the Helgoland Bight. Fregattenkapitan Peter Strasser looked at the line of low hanging grey clouds directly ahead of the ship. Despite apparent concern in the First Officer’s voice, Strasser was not worried. In the few months since he had been assigned to the Marine-Luftschiff-Abteilung (something he initially considered a humiliating demotion), the former gunnery officer had come to believe he was the fleet’s absolute expert in the capabilities of the zeppelin airship. Not only did he consider himself uniquely experienced in piloting ships through bad weather, he had finally come to appreciate these craft as potentially valuable adjuncts to the High Seas Fleet. Strasser was also beginning to see his charges as a means for the German Empire to bring death and terror to potential enemy populations, particularly the self-assured and arrogant shopkeepers of Great Britain. Or, more accurately, he was beginning to see how he could make the most of his recent assignment by selling the capabilities of the airship, and by extension, himself, to a navy and nation seeking to build its way into equality with the Royal Navy. He had just drafted a position paper arguing for a massive expansion of the Imperial Navy’s airship program. At the conclusion of this training flight in L-3, he intended to argue his case to all who would listen.
However, urgent calls from the helmsman brought Strasser from his reverie. The dark grey clouds, which only a few minutes ago seemed harmlessly distant, had suddenly begun to envelope the airship in near darkness. Now clearly frightened, the First Officer reported that barometric pressure was dropping fast. In minutes, lightning began to flash outside of the control gondola and the flexible plasticene windows were buffeted by strong gusts. Rain turned to hail. Unexpectedly L-3 had flown into the brunt of a major storm front blowing in from the North Sea.
Strasser ordered the ship below the cloud deck. Just as L-3 emerged into the open at an altitude of about 300 meters, the ship was hit by a series of sudden downdrafts. Strasser’s stomach churned as the ship began a sickening descent. He ordered the elevatorman to release all emergency ballast and raise the engines to flank speed. This seemed to work as the descent slowed, and then stopped. Then, L-3 began a sharp, uncontrolled, ascent. Just as the L-3 appeared to reach equilibrium again just below the roiling clouds, it was stuck by a violent lateral gust. The command gondola lurched to port, spilling the entire crew to the duralumin floor. Loose objects shot thru the gondola accompanied by the deafening screech of tearing metal. The unmanned rudder and elevator wheels both spun wildly.
Seeing that the other crewmen in the gondola were either hurt or temporarily stunned, Strasser pulled himself to his feet and grabbed the rudder wheel to steady himself. Unexpectedly, it turned freely in his hands as if the control cables were longer attached to anything. He leaned out of the open window and saw to his shock that L-3 had been torn nearly in two, the crumpled stern half still connected to the bow by only a few wires and girders. The entire ship was sinking quickly toward the heaving white-topped seas only a few hundred meters below.
It would be less than a minute before the ruined zeppelin struck the surface. Although he doubted he could be heard over the storm, Strasser grabbed the speaking tube and ordered the crew to their crash stations. Despite the impending crash landing, he felt surprisingly calm. Even with the storm, it was an unusually warm spring day, and with luck, most of his men would survive the crash and their time in the water with only minor hyperthermia. It appeared all of the gondola crew had returned to their senses. Hopefully everyone could swim well enough to reach some flotsam to hang onto. A good swimmer himself, Strasser began to remove his outercoat and service boots. The ship was going down within clear sight of Cuxhaven and he could see at least 3 trawlers within a kilometer. Help would certainly arrive soon.
Then, a diffuse yellowish glow began to grow through the haze and rain and reflect off the waves below. Horrified, Strasser knew this could mean only one thing: escaping hydrogen from the ripped gas cells above the gondola had somehow ignited. The entire ship would be engulfed by flames in seconds. Thinking only of himself at this point, Strasser crawled over the bridge rail and forced himself through the open plasticene window. Just as flames began to burst from the disintegrating envelope above the gondola, he jumped. Strasser fell over 50 meters to the churning sea and was killed instantly. In mere seconds, the flaming remains of L-3 followed him down. An engineer’s mate in the stern engine gondola, who rode the burning ship down to the sea, was the only survivor, miraculously living through the holocaust and 2 hours in the open water despite suffering severe burns.
With the loss of L-3, following on previous accidents to L-1 and L-2, the German Navy’s interest in the zeppelin airship as a weapon of war completely evaporated. While the High Seas Fleet continued to procure a few non-rigid Parseval-type ships for coastal uses, all orders for zeppelins were cancelled. The Army continued to experiment with zeppelins until the first few months of the Great War. However, after Z VI and Z VII were lost in combat, the Army withdrew its zeppelins from the front. By early 1915, all zeppelin airships in German service had been scrapped or lost in combat, bringing to an end Germany’s experimentation with the grandiose dreams of Count Zeppelin. In 1915, the Zeppelin firm itself abandoned work on rigid airships, switching to the design and production or large multi-engined aircraft such as Zeppelin-Staaken bombers and, in collaboration with Claudius Dornier, a series of large floatplanes.
However, this did not spell the end of German interest in naval aviation. Freed from the its initial obsession with the zeppelin technological dead end, the Imperial Navy sought out other technological innovations to counterbalance the Royal Navy’s numerical advantage over the High Seas Fleet. This is the story of one of these farsighted efforts and its undeniable effect on the course of history.
The Airplane joins the Kaiserliche Marine.
Initially, in part due to German public fascination with the giant zeppelins as well as Strasser’s influence on von Tirpitz, the Imperial Navy was relatively disinterested in adapting the airplane for naval missions. In 1910, however, the Kaiser’s younger brother, Prince Heinrich of Prussia, took up flying airplanes as a hobby. Heinrich was also becoming concerned that the cost of building up a massive dreadnought fleet had become excessive. He began to lobby his brother as well as the Navy for research into less expensive technological advances to offset the numerical dominance of the Royal Navy. In 1911, Prince Heinrich finally prevailed on the Navy to order a number of twin-engine flying boats from several of domestic and foreign manufacturers, resulting in the adoption of an American Curtiss design for series production by the Albatros concern.
In 1913, Heinrich also convinced von Tirpitz to have the obsolete battleship SMS Pommern fitted with an experimental flying-off platform on her fore 11-inch gun turret. Initial trials undertaken in the sheltered Baltic using modified Etrich (Rumpler) Taube monoplanes were completely unsuccessful, but several experimental biplanes based on British Avro and Sopwith designs were evaluated with greater success. In one instance, a float/wheel equipped Avro 503 launched from Pommern flew a several hour simulated bombing mission to Danzig and successfully navigated its way back to land alongside the battleship on its floats. This design was eventually put into series production by the Hannover and Albatros concerns in both floatplane and wheeled variants, becoming the first true naval aircraft in German service.
However, the short flying-off platform and slow speed of the pre-dreadnought battleship meant that wind conditions had to be very favorable for reliable aircraft launching. At the same time it was realized that inexpensive purpose-built airplane-carrying auxiliaries, rather than modified capital ships, would be a better way for the Kaiserliche Marine to effectively take advantage of aircraft, which at this point were considered primarily as potential aids in tactical reconnaissance and shell spotting, rather than offensive weapons in their own right. When trials with Pommern were initiated in the much less forgiving North Sea, this even more strongly emphasized the importance of better aircraft and more suitable ships if aircraft would ever be a useful adjunct to fleet operations.
Two parallel – and very different – approaches to fleet aviation were initially experimented with during the early years of the Great War: the slow, but well provisioned, seaplane tender; and the fast tactical Flugzeugkreuzer. Only in 1917, however, when the two concepts were merged into the true aircraft carrier was the ultimate potential of naval aviation reached.
Aircraft Tenders
These ships represented by far the more conservative approach to the introduction of naval aviation to the High Seas Fleet. Two such ships were commissioned during the Great War.
SMS Bremerhaven - Originally laid down as a 12,000 ton civilian passenger liner for service in the Baltic, Bremerhaven was purchased incomplete in 1913 by the Navy and refitted to carry and service 15 Albatros flying boats together with aviation fuel, spares, and other replenishment. She was completed in early 1914. A large internal hangar was provided to protect and maintain the aircraft while at sea and four swing-out cranes were provided to launch and retrieve them. Reflecting her as yet poorly defined function, Bremerhaven was also provided with a collapsible mast, ballast, and hydrogen tanks for Parseval non-rigid airships. With a maximum speed of 15 knots, Bremerhaven was not really suitable for use with the more modern elements of the High Seas Fleet. At the outbreak of war in August 1914, she was assigned to support the IV Battle Division, containing pre-dreadnoughts of the Deutschland and Braunschweig classes.
SMS Wotan - Using experience gained from the initial trials of Bremerhaven, this ship was designed built from the keel up as an airplane tender. The ship was completed in early 1916. Although somewhat smaller than Bremerhaven, her improved layout allowed her to ship more aircraft, including both twin-engined Albatros flying boats and single-engined Hannover floatplanes. Counterweight catapults were used to launch the seaplanes, while they were retrieved from the sea by means of large cranes. Wotan also dispensed with the airship servicing facilities that confused the function of the earlier ship. Upon completing her trials, Wotan was also assigned to the IV Battle Division.
With one exception, both seaplane tenders served throughout the war in the Baltic. On several occasions they accompanied the IV Division’s pre-dreadnoughts on shore bombardment missions against Russian positions, during which they began to develop a doctrine for naval artillery spotting. In October 1916, aircraft from both tenders, escorted by a force of predreadoughts and destroyers, launched an aerial attack on the damaged Russian battleship Petrovpavlosk, lying mine-damaged at Kronstadt. The attack was ineffective, the battleship suffering very little damage. Out of 18 aircraft, 8 were shot down by Russian coastal anti-aircraft batteries and 3 others lost in takeoff or landing accidents. As a military action, the Petrovpavlosk strike was a tactical failure. However, it proved to be a very valuable learning experience for the Imperial Navy and its naval aviators - a learning experience which would be very useful later in the war.
Airplane Cruisers
The airplane cruiser, or Fleugzeugkruezer, represented a much more novel, but ultimately unsuccessful, approach to incorporating aircraft into the High Seas Fleet. Four such ships were placed in service by 1915:
SMS Stralsund, SMS Friedrichshafen, SMS Hamburg, SMS Magdeburg – These ships were all originally laid down in 1910 and 1911 as light cruisers. However, prodded by Prince Heinrich, they were reconstructed after launching to function as airplane cruisers. As part of their reconstruction, the forward gun batteries were removed, and a long, cantilevered aircraft handling platform built over the forward hull. Displacing slightly over 4,200 tons, the ships were capable of 27 knots. All armament was placed aft. This initially comprised three 4.1” (105mm) guns, later replaced by two 5.7” (150mm) guns. Simple hangar facilities were provided beneath the handling platform. Cranes were provided to transfer airplanes from the hangars to the handling platform, and to retrieve them from the water. Under normal conditions, the Stralsund’s were capable of operating 6 single-engine floatplanes optimized for scouting. With extra aircraft shipped on the flying off platform, this number could be raised to 12.
Unlike the seaplane tenders, these ships were not provisioned to mount continuous or long term flying operations. Nor were they planned as scouts or long-range reconnaissance vessels. Rather, they were envisaged as fast craft capable of launching aircraft as needed to assist with artillery spotting during tactical fleet operations. It was hoped that their high speed would allow them to move fairly rapidly to different locations during fleet engagements, launch their spotting aircraft to assist in tactical situations, and then withdraw behind the battle lines to retrieve them. Although the tactical Flugzeugkruezer concept proved to be completely unsound when tested during the battle of Jutland in 1916, these ships helped formed the basis for the large aircraft carriers which changed the course of naval warfare.
Aircraft Carriers
By late 1914, the High Seas Fleet found itself with number of battlecruisers under order or already laid down that would be unlikely to be completed in several years. Under the influence of Prince Heinrich, the navy agreed to rebuild several as true aircraft carriers. This decision was also made in light of growing evidence that allied powers were working in the same direction. HMS Ark Royal, a converted steamer, was providing limited air support for Allied landings in the Dardanelles, and even the Japanese had staged an effective air raid on German forces at Tsingtao as early as 1914 from the Seaplane tender IJN Wakamiya.
Most critically, however, was the discovery of intelligence suggesting that the Royal Navy was itself contemplating the partial or full conversion of several incomplete battlecruisers to function as full-fledged aircraft carriers. Prodded by Prince Heinrich, and determined not to be second fiddle to the Grand Fleet once again in the introduction of potentially revolutionary warships, the Kaiserliche Marine ordered a crash program to redesign and refit the battlecruiser Hindenburg, then well under construction at Wilhelmshaven as a partial deck aircraft carrier. This would be followed as soon as practicable by the more thorough reconstruction of two further battlecruisers just beginning construction, Mackensen and Prinz Eitel Freidrich, as full-deck aircraft carriers. Plans were also put underway to complete the two remaining incomplete Mackensen-class ships as aircraft carriers as soon as practicable after the performance of the first three carriers could be judged and improvements could be made.
SMS Hindenburg. Construction of this ship was fairly far along when the decision to convert her was made, and she had already been launched. As such, her conversion was far less thorough than that of the following two ships. However, because her reconstruction also required redesign and removal of numerous structural elements, armor, weapons, and equipment that had already been installed, she was not completed until late 1916, only a few months before the two Mackensen-class ships.
Hindenburg emerged as a hybrid. Much of her midsection, including the casemated 5.9 inch secondary batteries, twin funnels, superstructure layout, and spotting tops was not radically different from the original battlecruiser design. She also retained the basic engineering and belt armor which had already been installed, but all deck armor was removed. The fore and aft main battery was removed, but to save money and time, the armored barbettes and HG magazine spaces were retained. Long wooden flight decks were placed at the bow and stern. The fore deck was used for rolling takeoffs and the stern deck for landings. The flight decks were constructed over fully equipped hangars capable of carrying up to 12 aircraft each. The armored barbettes were reconfigured to contain ammunition stores and aviation fuel. The two decks were connected by a narrow rail system allowing transfer of aircraft between flight decks. No elevators were provided; aircraft were lifted through a hatch to the deck by crane.
Figure 2 – SMS Hindenburg as converted to aircraft carrier 1916
When completed, Hindenburg displaced only 25,800 tons fully loaded, a significant weight saving made possible by the deletion of the main battery and much of the ship’s armor, except for the main belt. Her sleek hull shape and contours remained the same as the original battlecruiser, and with the same engineering, she was capable of over 29 kts. After builder’s trials in the Baltic she was formally commissioned into the Imperial Navy on December 29, 1916.
SMS Mackensen; SMS Prinz Eitel Freidrich – Because work on these ships had only begun when the decision was made to convert them, they were much more thoroughly reconstructed than Hindenburg. Also, because they were based on much larger designs, they emerged in all ways as significantly more capable ships. Paradoxically, once basic redesign was done, they could be completed much more quickly than Hindenburg, which required substantial removal of previously installed equipment. Both ships were completed within two months of Hindenburg, giving the High Seas Fleet 3 modern aircraft carriers by March 1917.
The Mackensens were much more revolutionary in concept and design than Hindenburg or most other early British, Japanese, or US aircraft carriers converted from cruisers or capital ships. The ships were true full deck carriers. Because the originally planned engineering spaces were left relatively unchanged, a single full-length hangar could not be installed, necessitating retention of the cumbersome twin hangars rather than a single large space. As a result, the number of aircraft the ships could carry and service was less than might otherwise be imagined given their size, generally less than 50. Two true elevators were provided, one serving each hangar. Except for a small structure for the control of flying operations and signaling, the ships had essentially no superstructure. A small bridge was cantilevered to starboard beneath the fight deck, and smoke was trunked into a single large funnel exiting at a roughly 90% angle, also to starboard.
Figure 3 – SMS Mackensen as completed as full-deck aircraft carrier 1917
With the elimination of the main battery and magazines, the armor belt could be reduced to protect only the engineering spaces and the much smaller magazines and fuel bunkers required to support air operations. Anti-torpedo protection remained as in the battlecruiser design. Only a small “anti-torpedo” and anti-aircraft battery was retained. Because of these many weight-saving modifications to the original design, the full load displacement of the Mackensens was less than 25,000 tons, as opposed to the 36,000 tons as originally designed. With their original engineering retained, this gave them the phenomenal top speed of 33.5 kts during initial trials.
Following trials in the Baltic, all three aircraft carriers were assigned to the High Seas Fleet’s battlecruiser squadron under the command of Admiral Franz Von Hipper. In all formal correspondence they were still referred to as “battlecruisers”, in an apparently successful disinformation campaign to keep the British confused regarding their true design and purpose, as evidenced by the following excerpt from the forward of 1917 edition of Jane’s Fighting Ships:
“Uncertainty still surrounds the status of Hindenburg and the other German capital ships that were under construction at the start of the war. It is known the battleships Bayern and Baden have entered the fleet. This is apparently also the case with the Hindenburg and at least two other battlecruisers, according to official German pronouncements. However, no clear photographs of these ships have appeared in the German naval press, and there have been unofficial reports that, because of delays in procuring armor and armament, one or all of them may have been converted into airplane carriers or cancelled altogether. The reports that these ships have been converted are highly questionable. It is improbable that Hindenburg, which was known to be nearing completion last year, would have been subject to such a radical reconstruction at this late date. If any of these ships have been completed, they would be much more useful to the German Navy as battle cruisers, especially given the losses at Dogger Bank and Jutland. Thus, until the actual situation is determined, the Royal Navy would be wise to presume all three are now commissioned battlecruisers in the High Seas Fleet and respond accordingly.” (JFS 1917, pp ix-x).
The three carriers were initially considered scouting units, using their aircraft to give the Battlecruiser squadron effective aerial reconnaissance in future raids on the British Coast or in any future Jutland-like engagements. However, Prince Heinrich would not go away. Under constant prodding by the Prince, and supported by the Kaiser himself, Hipper began to develop a plan to use his aircraft carriers to attack the British fleet itself. As detailed in Von Hipper’s memoirs, he became convinced that a surprise airstrike on the Royal Navy lying in Scapa Flow itself might be the only way to renew the morale of the Imperial Navy, force the Royal Navy to move its main fleet anchorage out of the North Sea, thereby allowing the High Seas Fleet opportunity to sortie against the Allied forces on the western front, and change the entire dynamic of the stalemate. As events transpired, Von Hipper was too optimistic regarding possible British responses, but there is no doubt that the German Navy’s April 1918 air attack on a major portion of the Grand Fleet at anchor at Scapa Flow changed the course of naval and aviation history.
SMS Graf Spee and SMS Furst Bismarck
Following the success of the Scapa Flow attack, followed closely by the somewhat less successful but nonetheless shocking British carrier strike on the Imperial shipyards at Wilhelmshaven, the Navy immediately put in motion plans to reconstruct these final two Mackensen-class ships as aircraft carriers. As planned, the reconstructions would be even more thorough than first two Mackensen conversions. Engineering spaces were redesigned so the ships would have a full-length hangar bay, and based upon experience with the laterally overhanging funnels of the earlier carriers, smoke would be trunked into a large upright funnel on the starboard side, combined with a more substantial superstructure combining bridge and air operations.
Figure 4 - The Graf Spee and Furst Bismarck as they would have appeared if completed as aircraft carriers 1919
However, the revolutions of 1918-1920 disrupted their construction and, by the time order was restored, the political situation did not favor completion of the ships. Luckily for Germany, equivalent political instability in both France and Britain made negotiation of an armistice on somewhat favorable terms to Germany possible. The 1919 armistice required that new military construction, procurement, and deployments be suspended by all belligerents until terms of a final peace agreement was worked out. Because the ships were not finished, work on them was suspended, and the Provisional Government eventually decided to have them scrapped.
When the United States, China, and Japan refused to sign the Treaty of Rome formally ending the Great War, Europe entered a long period of unstable peace. The 1919 armistice became the de facto peace agreement in Europe, eventually supplemented by a series of bilateral treaty agreements between the main powers. All the principal European powers adhered to the armistice, not because they were all satisfied with its terms, but primarily because they were all were effectively bankrupt, they had already partially demobilized as required by the armistice, and because all were facing significant internal revolutionary movements at home.
By 1927, the political and economic situation most major European powers had largely stabilized, and they could again contemplate rebuilding their armed forces. While few men in authority in Berlin, Paris, and London desired a resumption of the Great War, the armistice did leave many outstanding issues in limbo, not the least of which was future status of Belgium, the former Austro-Hungarian Empire, and the status of Poland and other Soviet-Occupied “Brest-Litovsk Territories” abandoned by Germany during the height of the 1918-20 revolution.
Also, all major European powers were concerned by the rapid growth and influence of the Soviet Union, the aggressive new nationalist government in Italy, and to various degrees they were also suspicious of the United States and Japan. The US and Japan were on a collision course in the Pacific and had continued to build up their naval strength during the 1919-1927 period, while that of Britain, Germany and France had lagged substantially behind. The US Navy was by far the largest and most modern fleet in the world, and Japan’s was not close behind, whereas as late as 1925, many ships of the German and British navies were unmanned, inactive, and slowly rusting away in their harbors. Also, Germany still had poor relationships with both the US and Japan. Britain, for her part, was not willing to see its erstwhile allies both eclipse the Royal Navy. Thus, as economic improvements permitted, both Germany and Britain considered it necessary to rebuild their navies, resurrecting to a small degree their naval rivalry. New battleships, cruisers, destroyers, submarines, and, of course, aircraft carriers were ordered. As with all other major powers, future carriers built for the Kaiserliche Marine were be designed and built as such from the keel up.
Comments and suggestions from those more informed than I are more than welcome.
A Brief History of German Naval Aviation 1910-1947
Preface – 30 May 1914
Airship L-3 had just passed over Cuxhaven into the Helgoland Bight. Fregattenkapitan Peter Strasser looked at the line of low hanging grey clouds directly ahead of the ship. Despite apparent concern in the First Officer’s voice, Strasser was not worried. In the few months since he had been assigned to the Marine-Luftschiff-Abteilung (something he initially considered a humiliating demotion), the former gunnery officer had come to believe he was the fleet’s absolute expert in the capabilities of the zeppelin airship. Not only did he consider himself uniquely experienced in piloting ships through bad weather, he had finally come to appreciate these craft as potentially valuable adjuncts to the High Seas Fleet. Strasser was also beginning to see his charges as a means for the German Empire to bring death and terror to potential enemy populations, particularly the self-assured and arrogant shopkeepers of Great Britain. Or, more accurately, he was beginning to see how he could make the most of his recent assignment by selling the capabilities of the airship, and by extension, himself, to a navy and nation seeking to build its way into equality with the Royal Navy. He had just drafted a position paper arguing for a massive expansion of the Imperial Navy’s airship program. At the conclusion of this training flight in L-3, he intended to argue his case to all who would listen.
However, urgent calls from the helmsman brought Strasser from his reverie. The dark grey clouds, which only a few minutes ago seemed harmlessly distant, had suddenly begun to envelope the airship in near darkness. Now clearly frightened, the First Officer reported that barometric pressure was dropping fast. In minutes, lightning began to flash outside of the control gondola and the flexible plasticene windows were buffeted by strong gusts. Rain turned to hail. Unexpectedly L-3 had flown into the brunt of a major storm front blowing in from the North Sea.
Strasser ordered the ship below the cloud deck. Just as L-3 emerged into the open at an altitude of about 300 meters, the ship was hit by a series of sudden downdrafts. Strasser’s stomach churned as the ship began a sickening descent. He ordered the elevatorman to release all emergency ballast and raise the engines to flank speed. This seemed to work as the descent slowed, and then stopped. Then, L-3 began a sharp, uncontrolled, ascent. Just as the L-3 appeared to reach equilibrium again just below the roiling clouds, it was stuck by a violent lateral gust. The command gondola lurched to port, spilling the entire crew to the duralumin floor. Loose objects shot thru the gondola accompanied by the deafening screech of tearing metal. The unmanned rudder and elevator wheels both spun wildly.
Seeing that the other crewmen in the gondola were either hurt or temporarily stunned, Strasser pulled himself to his feet and grabbed the rudder wheel to steady himself. Unexpectedly, it turned freely in his hands as if the control cables were longer attached to anything. He leaned out of the open window and saw to his shock that L-3 had been torn nearly in two, the crumpled stern half still connected to the bow by only a few wires and girders. The entire ship was sinking quickly toward the heaving white-topped seas only a few hundred meters below.
It would be less than a minute before the ruined zeppelin struck the surface. Although he doubted he could be heard over the storm, Strasser grabbed the speaking tube and ordered the crew to their crash stations. Despite the impending crash landing, he felt surprisingly calm. Even with the storm, it was an unusually warm spring day, and with luck, most of his men would survive the crash and their time in the water with only minor hyperthermia. It appeared all of the gondola crew had returned to their senses. Hopefully everyone could swim well enough to reach some flotsam to hang onto. A good swimmer himself, Strasser began to remove his outercoat and service boots. The ship was going down within clear sight of Cuxhaven and he could see at least 3 trawlers within a kilometer. Help would certainly arrive soon.
Then, a diffuse yellowish glow began to grow through the haze and rain and reflect off the waves below. Horrified, Strasser knew this could mean only one thing: escaping hydrogen from the ripped gas cells above the gondola had somehow ignited. The entire ship would be engulfed by flames in seconds. Thinking only of himself at this point, Strasser crawled over the bridge rail and forced himself through the open plasticene window. Just as flames began to burst from the disintegrating envelope above the gondola, he jumped. Strasser fell over 50 meters to the churning sea and was killed instantly. In mere seconds, the flaming remains of L-3 followed him down. An engineer’s mate in the stern engine gondola, who rode the burning ship down to the sea, was the only survivor, miraculously living through the holocaust and 2 hours in the open water despite suffering severe burns.
With the loss of L-3, following on previous accidents to L-1 and L-2, the German Navy’s interest in the zeppelin airship as a weapon of war completely evaporated. While the High Seas Fleet continued to procure a few non-rigid Parseval-type ships for coastal uses, all orders for zeppelins were cancelled. The Army continued to experiment with zeppelins until the first few months of the Great War. However, after Z VI and Z VII were lost in combat, the Army withdrew its zeppelins from the front. By early 1915, all zeppelin airships in German service had been scrapped or lost in combat, bringing to an end Germany’s experimentation with the grandiose dreams of Count Zeppelin. In 1915, the Zeppelin firm itself abandoned work on rigid airships, switching to the design and production or large multi-engined aircraft such as Zeppelin-Staaken bombers and, in collaboration with Claudius Dornier, a series of large floatplanes.
However, this did not spell the end of German interest in naval aviation. Freed from the its initial obsession with the zeppelin technological dead end, the Imperial Navy sought out other technological innovations to counterbalance the Royal Navy’s numerical advantage over the High Seas Fleet. This is the story of one of these farsighted efforts and its undeniable effect on the course of history.
The Airplane joins the Kaiserliche Marine.
Initially, in part due to German public fascination with the giant zeppelins as well as Strasser’s influence on von Tirpitz, the Imperial Navy was relatively disinterested in adapting the airplane for naval missions. In 1910, however, the Kaiser’s younger brother, Prince Heinrich of Prussia, took up flying airplanes as a hobby. Heinrich was also becoming concerned that the cost of building up a massive dreadnought fleet had become excessive. He began to lobby his brother as well as the Navy for research into less expensive technological advances to offset the numerical dominance of the Royal Navy. In 1911, Prince Heinrich finally prevailed on the Navy to order a number of twin-engine flying boats from several of domestic and foreign manufacturers, resulting in the adoption of an American Curtiss design for series production by the Albatros concern.
In 1913, Heinrich also convinced von Tirpitz to have the obsolete battleship SMS Pommern fitted with an experimental flying-off platform on her fore 11-inch gun turret. Initial trials undertaken in the sheltered Baltic using modified Etrich (Rumpler) Taube monoplanes were completely unsuccessful, but several experimental biplanes based on British Avro and Sopwith designs were evaluated with greater success. In one instance, a float/wheel equipped Avro 503 launched from Pommern flew a several hour simulated bombing mission to Danzig and successfully navigated its way back to land alongside the battleship on its floats. This design was eventually put into series production by the Hannover and Albatros concerns in both floatplane and wheeled variants, becoming the first true naval aircraft in German service.
However, the short flying-off platform and slow speed of the pre-dreadnought battleship meant that wind conditions had to be very favorable for reliable aircraft launching. At the same time it was realized that inexpensive purpose-built airplane-carrying auxiliaries, rather than modified capital ships, would be a better way for the Kaiserliche Marine to effectively take advantage of aircraft, which at this point were considered primarily as potential aids in tactical reconnaissance and shell spotting, rather than offensive weapons in their own right. When trials with Pommern were initiated in the much less forgiving North Sea, this even more strongly emphasized the importance of better aircraft and more suitable ships if aircraft would ever be a useful adjunct to fleet operations.
Two parallel – and very different – approaches to fleet aviation were initially experimented with during the early years of the Great War: the slow, but well provisioned, seaplane tender; and the fast tactical Flugzeugkreuzer. Only in 1917, however, when the two concepts were merged into the true aircraft carrier was the ultimate potential of naval aviation reached.
Aircraft Tenders
These ships represented by far the more conservative approach to the introduction of naval aviation to the High Seas Fleet. Two such ships were commissioned during the Great War.
SMS Bremerhaven - Originally laid down as a 12,000 ton civilian passenger liner for service in the Baltic, Bremerhaven was purchased incomplete in 1913 by the Navy and refitted to carry and service 15 Albatros flying boats together with aviation fuel, spares, and other replenishment. She was completed in early 1914. A large internal hangar was provided to protect and maintain the aircraft while at sea and four swing-out cranes were provided to launch and retrieve them. Reflecting her as yet poorly defined function, Bremerhaven was also provided with a collapsible mast, ballast, and hydrogen tanks for Parseval non-rigid airships. With a maximum speed of 15 knots, Bremerhaven was not really suitable for use with the more modern elements of the High Seas Fleet. At the outbreak of war in August 1914, she was assigned to support the IV Battle Division, containing pre-dreadnoughts of the Deutschland and Braunschweig classes.
SMS Wotan - Using experience gained from the initial trials of Bremerhaven, this ship was designed built from the keel up as an airplane tender. The ship was completed in early 1916. Although somewhat smaller than Bremerhaven, her improved layout allowed her to ship more aircraft, including both twin-engined Albatros flying boats and single-engined Hannover floatplanes. Counterweight catapults were used to launch the seaplanes, while they were retrieved from the sea by means of large cranes. Wotan also dispensed with the airship servicing facilities that confused the function of the earlier ship. Upon completing her trials, Wotan was also assigned to the IV Battle Division.
With one exception, both seaplane tenders served throughout the war in the Baltic. On several occasions they accompanied the IV Division’s pre-dreadnoughts on shore bombardment missions against Russian positions, during which they began to develop a doctrine for naval artillery spotting. In October 1916, aircraft from both tenders, escorted by a force of predreadoughts and destroyers, launched an aerial attack on the damaged Russian battleship Petrovpavlosk, lying mine-damaged at Kronstadt. The attack was ineffective, the battleship suffering very little damage. Out of 18 aircraft, 8 were shot down by Russian coastal anti-aircraft batteries and 3 others lost in takeoff or landing accidents. As a military action, the Petrovpavlosk strike was a tactical failure. However, it proved to be a very valuable learning experience for the Imperial Navy and its naval aviators - a learning experience which would be very useful later in the war.
Airplane Cruisers
The airplane cruiser, or Fleugzeugkruezer, represented a much more novel, but ultimately unsuccessful, approach to incorporating aircraft into the High Seas Fleet. Four such ships were placed in service by 1915:
SMS Stralsund, SMS Friedrichshafen, SMS Hamburg, SMS Magdeburg – These ships were all originally laid down in 1910 and 1911 as light cruisers. However, prodded by Prince Heinrich, they were reconstructed after launching to function as airplane cruisers. As part of their reconstruction, the forward gun batteries were removed, and a long, cantilevered aircraft handling platform built over the forward hull. Displacing slightly over 4,200 tons, the ships were capable of 27 knots. All armament was placed aft. This initially comprised three 4.1” (105mm) guns, later replaced by two 5.7” (150mm) guns. Simple hangar facilities were provided beneath the handling platform. Cranes were provided to transfer airplanes from the hangars to the handling platform, and to retrieve them from the water. Under normal conditions, the Stralsund’s were capable of operating 6 single-engine floatplanes optimized for scouting. With extra aircraft shipped on the flying off platform, this number could be raised to 12.
Unlike the seaplane tenders, these ships were not provisioned to mount continuous or long term flying operations. Nor were they planned as scouts or long-range reconnaissance vessels. Rather, they were envisaged as fast craft capable of launching aircraft as needed to assist with artillery spotting during tactical fleet operations. It was hoped that their high speed would allow them to move fairly rapidly to different locations during fleet engagements, launch their spotting aircraft to assist in tactical situations, and then withdraw behind the battle lines to retrieve them. Although the tactical Flugzeugkruezer concept proved to be completely unsound when tested during the battle of Jutland in 1916, these ships helped formed the basis for the large aircraft carriers which changed the course of naval warfare.
Aircraft Carriers
By late 1914, the High Seas Fleet found itself with number of battlecruisers under order or already laid down that would be unlikely to be completed in several years. Under the influence of Prince Heinrich, the navy agreed to rebuild several as true aircraft carriers. This decision was also made in light of growing evidence that allied powers were working in the same direction. HMS Ark Royal, a converted steamer, was providing limited air support for Allied landings in the Dardanelles, and even the Japanese had staged an effective air raid on German forces at Tsingtao as early as 1914 from the Seaplane tender IJN Wakamiya.
Most critically, however, was the discovery of intelligence suggesting that the Royal Navy was itself contemplating the partial or full conversion of several incomplete battlecruisers to function as full-fledged aircraft carriers. Prodded by Prince Heinrich, and determined not to be second fiddle to the Grand Fleet once again in the introduction of potentially revolutionary warships, the Kaiserliche Marine ordered a crash program to redesign and refit the battlecruiser Hindenburg, then well under construction at Wilhelmshaven as a partial deck aircraft carrier. This would be followed as soon as practicable by the more thorough reconstruction of two further battlecruisers just beginning construction, Mackensen and Prinz Eitel Freidrich, as full-deck aircraft carriers. Plans were also put underway to complete the two remaining incomplete Mackensen-class ships as aircraft carriers as soon as practicable after the performance of the first three carriers could be judged and improvements could be made.
SMS Hindenburg. Construction of this ship was fairly far along when the decision to convert her was made, and she had already been launched. As such, her conversion was far less thorough than that of the following two ships. However, because her reconstruction also required redesign and removal of numerous structural elements, armor, weapons, and equipment that had already been installed, she was not completed until late 1916, only a few months before the two Mackensen-class ships.
Hindenburg emerged as a hybrid. Much of her midsection, including the casemated 5.9 inch secondary batteries, twin funnels, superstructure layout, and spotting tops was not radically different from the original battlecruiser design. She also retained the basic engineering and belt armor which had already been installed, but all deck armor was removed. The fore and aft main battery was removed, but to save money and time, the armored barbettes and HG magazine spaces were retained. Long wooden flight decks were placed at the bow and stern. The fore deck was used for rolling takeoffs and the stern deck for landings. The flight decks were constructed over fully equipped hangars capable of carrying up to 12 aircraft each. The armored barbettes were reconfigured to contain ammunition stores and aviation fuel. The two decks were connected by a narrow rail system allowing transfer of aircraft between flight decks. No elevators were provided; aircraft were lifted through a hatch to the deck by crane.
Figure 2 – SMS Hindenburg as converted to aircraft carrier 1916
When completed, Hindenburg displaced only 25,800 tons fully loaded, a significant weight saving made possible by the deletion of the main battery and much of the ship’s armor, except for the main belt. Her sleek hull shape and contours remained the same as the original battlecruiser, and with the same engineering, she was capable of over 29 kts. After builder’s trials in the Baltic she was formally commissioned into the Imperial Navy on December 29, 1916.
SMS Mackensen; SMS Prinz Eitel Freidrich – Because work on these ships had only begun when the decision was made to convert them, they were much more thoroughly reconstructed than Hindenburg. Also, because they were based on much larger designs, they emerged in all ways as significantly more capable ships. Paradoxically, once basic redesign was done, they could be completed much more quickly than Hindenburg, which required substantial removal of previously installed equipment. Both ships were completed within two months of Hindenburg, giving the High Seas Fleet 3 modern aircraft carriers by March 1917.
The Mackensens were much more revolutionary in concept and design than Hindenburg or most other early British, Japanese, or US aircraft carriers converted from cruisers or capital ships. The ships were true full deck carriers. Because the originally planned engineering spaces were left relatively unchanged, a single full-length hangar could not be installed, necessitating retention of the cumbersome twin hangars rather than a single large space. As a result, the number of aircraft the ships could carry and service was less than might otherwise be imagined given their size, generally less than 50. Two true elevators were provided, one serving each hangar. Except for a small structure for the control of flying operations and signaling, the ships had essentially no superstructure. A small bridge was cantilevered to starboard beneath the fight deck, and smoke was trunked into a single large funnel exiting at a roughly 90% angle, also to starboard.
Figure 3 – SMS Mackensen as completed as full-deck aircraft carrier 1917
With the elimination of the main battery and magazines, the armor belt could be reduced to protect only the engineering spaces and the much smaller magazines and fuel bunkers required to support air operations. Anti-torpedo protection remained as in the battlecruiser design. Only a small “anti-torpedo” and anti-aircraft battery was retained. Because of these many weight-saving modifications to the original design, the full load displacement of the Mackensens was less than 25,000 tons, as opposed to the 36,000 tons as originally designed. With their original engineering retained, this gave them the phenomenal top speed of 33.5 kts during initial trials.
Following trials in the Baltic, all three aircraft carriers were assigned to the High Seas Fleet’s battlecruiser squadron under the command of Admiral Franz Von Hipper. In all formal correspondence they were still referred to as “battlecruisers”, in an apparently successful disinformation campaign to keep the British confused regarding their true design and purpose, as evidenced by the following excerpt from the forward of 1917 edition of Jane’s Fighting Ships:
“Uncertainty still surrounds the status of Hindenburg and the other German capital ships that were under construction at the start of the war. It is known the battleships Bayern and Baden have entered the fleet. This is apparently also the case with the Hindenburg and at least two other battlecruisers, according to official German pronouncements. However, no clear photographs of these ships have appeared in the German naval press, and there have been unofficial reports that, because of delays in procuring armor and armament, one or all of them may have been converted into airplane carriers or cancelled altogether. The reports that these ships have been converted are highly questionable. It is improbable that Hindenburg, which was known to be nearing completion last year, would have been subject to such a radical reconstruction at this late date. If any of these ships have been completed, they would be much more useful to the German Navy as battle cruisers, especially given the losses at Dogger Bank and Jutland. Thus, until the actual situation is determined, the Royal Navy would be wise to presume all three are now commissioned battlecruisers in the High Seas Fleet and respond accordingly.” (JFS 1917, pp ix-x).
The three carriers were initially considered scouting units, using their aircraft to give the Battlecruiser squadron effective aerial reconnaissance in future raids on the British Coast or in any future Jutland-like engagements. However, Prince Heinrich would not go away. Under constant prodding by the Prince, and supported by the Kaiser himself, Hipper began to develop a plan to use his aircraft carriers to attack the British fleet itself. As detailed in Von Hipper’s memoirs, he became convinced that a surprise airstrike on the Royal Navy lying in Scapa Flow itself might be the only way to renew the morale of the Imperial Navy, force the Royal Navy to move its main fleet anchorage out of the North Sea, thereby allowing the High Seas Fleet opportunity to sortie against the Allied forces on the western front, and change the entire dynamic of the stalemate. As events transpired, Von Hipper was too optimistic regarding possible British responses, but there is no doubt that the German Navy’s April 1918 air attack on a major portion of the Grand Fleet at anchor at Scapa Flow changed the course of naval and aviation history.
SMS Graf Spee and SMS Furst Bismarck
Following the success of the Scapa Flow attack, followed closely by the somewhat less successful but nonetheless shocking British carrier strike on the Imperial shipyards at Wilhelmshaven, the Navy immediately put in motion plans to reconstruct these final two Mackensen-class ships as aircraft carriers. As planned, the reconstructions would be even more thorough than first two Mackensen conversions. Engineering spaces were redesigned so the ships would have a full-length hangar bay, and based upon experience with the laterally overhanging funnels of the earlier carriers, smoke would be trunked into a large upright funnel on the starboard side, combined with a more substantial superstructure combining bridge and air operations.
Figure 4 - The Graf Spee and Furst Bismarck as they would have appeared if completed as aircraft carriers 1919
However, the revolutions of 1918-1920 disrupted their construction and, by the time order was restored, the political situation did not favor completion of the ships. Luckily for Germany, equivalent political instability in both France and Britain made negotiation of an armistice on somewhat favorable terms to Germany possible. The 1919 armistice required that new military construction, procurement, and deployments be suspended by all belligerents until terms of a final peace agreement was worked out. Because the ships were not finished, work on them was suspended, and the Provisional Government eventually decided to have them scrapped.
When the United States, China, and Japan refused to sign the Treaty of Rome formally ending the Great War, Europe entered a long period of unstable peace. The 1919 armistice became the de facto peace agreement in Europe, eventually supplemented by a series of bilateral treaty agreements between the main powers. All the principal European powers adhered to the armistice, not because they were all satisfied with its terms, but primarily because they were all were effectively bankrupt, they had already partially demobilized as required by the armistice, and because all were facing significant internal revolutionary movements at home.
By 1927, the political and economic situation most major European powers had largely stabilized, and they could again contemplate rebuilding their armed forces. While few men in authority in Berlin, Paris, and London desired a resumption of the Great War, the armistice did leave many outstanding issues in limbo, not the least of which was future status of Belgium, the former Austro-Hungarian Empire, and the status of Poland and other Soviet-Occupied “Brest-Litovsk Territories” abandoned by Germany during the height of the 1918-20 revolution.
Also, all major European powers were concerned by the rapid growth and influence of the Soviet Union, the aggressive new nationalist government in Italy, and to various degrees they were also suspicious of the United States and Japan. The US and Japan were on a collision course in the Pacific and had continued to build up their naval strength during the 1919-1927 period, while that of Britain, Germany and France had lagged substantially behind. The US Navy was by far the largest and most modern fleet in the world, and Japan’s was not close behind, whereas as late as 1925, many ships of the German and British navies were unmanned, inactive, and slowly rusting away in their harbors. Also, Germany still had poor relationships with both the US and Japan. Britain, for her part, was not willing to see its erstwhile allies both eclipse the Royal Navy. Thus, as economic improvements permitted, both Germany and Britain considered it necessary to rebuild their navies, resurrecting to a small degree their naval rivalry. New battleships, cruisers, destroyers, submarines, and, of course, aircraft carriers were ordered. As with all other major powers, future carriers built for the Kaiserliche Marine were be designed and built as such from the keel up.