Submarine Aircraft Carrier - Early History (World War I)

Early History (World War I)

Germany was the first nation to experiment with submarine aircraft carriers, inspired by the Imperial German Naval Air Service commander Oberleutnant zur See Lothar von Arnauld de la Perière. He commanded a unit of two reconnaissance seaplanes (Friedrichshafen FF.29s) in Zeebrugge which had been recently occupied by the Imperial German Army in the early months of World War I. One of the first U-Boats to arrive at the Zeebrugge base was Kapitänleutnant Walther Forstmann's U-12, which was to play the role of submarine aircraft carrier.

Forstmann ordered the modification of the unarmed FF-29 seaplanes so they could carry 26½ lb (12 kg) bombs. This unit made history when on 25 December 1914, one of its newly modified aircraft flew across the English Channel and up the River Thames, dropping its bombs on the outskirts of London where they did little damage. Although chased for a time by three British interceptors, it returned to base safely. On this first ever bombing mission it became apparent that the aircraft suffered more from fuel problems and lack of range than from British defences.

Later encouraged by this success, Arnauld and Forstmann theorized that they could effectively increase the range of their seaplanes by taking the aircraft to the sea on the deck of submarine and placing it in a takeoff position, then launching the planes after the sub partially submerged, allowing the plane to float off. On 15 January 1915, U-12 left their Zeebrugge base transporting one bomb-armed FF-29 on its deck. The submarine left the harbor, seemingly dwarfed by the 53 ft 2 in (16.21 m) wingspan of the fixed wing aircraft, which stretched almost ⅓ of the 188 ft (57 m) length of the small coastal patrol submarine. After U-12 had left the safety of the breakwater, however, the captain realized that the heavy swells they were encountering might swamp the aircraft and endanger the operation, he ordered the immediate launch of the seaplane.

Forstmann flooded the sub's forward tanks and despite the pitching of the boat, Arnauld in command, floated the seaplane off the deck's surface without much difficulty and took off. He had originally intended to rendezvous with the sub, but later decided against it. After gaining sufficient altitude, Arnauld's plane left for the British coast. The German officer apparently flew along the English coastline undetected and then made his way back to occupied Zeebrugge. The experiment had been successful, in the sense that the aircraft had been carried out to sea and had safely floated off the submarine's deck. However, it was obvious that some improvements were needed in the procedure and setup.

Arnauld and Forstmann proposed further development experiments to the German Naval Command, but were vetoed as their project was considered technically impracticable. The plans were kept on ice until 1917, when they were reinvestigated in the hope that they would increase the striking power of new German subs such as the long-range cruise-type Unterseeboote, which were to be equipped with aircraft for scouting purposes - little seaplanes that could be quickly assembled and dismantled onboard and kept in special compartments on deck - but the idea was eventually abandoned as the war came to an end.

Two of the aircraft designs created for that purpose were the biplane Hansa Brandenburg W.20 and low-wing monoplane Luftfahrzeug Gesellschaft L.F.G. Stralsund V.19. The first type was designed in 1917 for use aboard the Cruiser submarines that never went into service. The second model was an experimental plane of the flimsiest construction for use in the calmest of seas.

The British also experimented with the aircraft-carrying submarine concept when HM Submarine E22 was fitted out in a manner similar to the German U-Boat. It was to be capable of launching its two Sopwith Schneider/Sopwith Baby floatplanes in 1916. However, just as in the German experiment, the aircraft were carried outside and the submarine could not submerge without losing them.