HYBRID WARSHIP Amalgamation of Big Guns and Aircraft Gotland

The third navy to consider a hybrid vessel was that of Sweden, and the result was the only such ship to be constructed by a European nation between the wars. The genesis of Gotland, as the vessel was eventually named, can be traced to 1925, when the Ministry of Defence decided upon replacing two old ships, the cruiser Fylgia and the minelayer Klas Fleming. A committee was appointed to study the matter of replacement and future naval needs in general; one of its recommendations, given in December 1926, was for a small (4500 ton) seaplane carrier with a capacity of twelve aircraft. The Naval Construction Board, however, was not pleased with the idea, and altered the concept to one of a vessel combining cruiser, seaplane carrier and minelayer functions.
Plans were accordingly drawn up for a 5000 ton ship armed with six 6in guns in three twin turrets, a speed of 28 knots, equipped with two catapults and carrying eight aircraft.The design was finalised in January 1927 and on 13 May the Riksdag (parliament) authorised 16.5 million kroner in construction funds.
Unfortunately, this was not enough. When tenders were invited in March 1928 it was found that no Swedish shipbuilding firm would undertake construction under such a tight budget. So the Naval Construction Board designers marched back to the draughting table to scale the ship down. A major change was a shorter hull, reducing
displacement and forcing elimination of the superimposed turret forward. Its guns were instead mounted in casemates abreast the superstructure, the last time such mountings were employed on a major naval vessel. The redesign also eliminated one of the catapults, partly for economic reasons, partly because it was feared that outboard placement might make them difficult or impossible to use in moderate seas. A single centreline catapult was substituted; for some years afterward, however, foreign naval reference works persisted in showing the ship with the two catapults of the original design.

A construction contract was awarded on 7 June 1930 to two well-known Göteborg shipbuilding firms, Götaverken as the main builder and Lindholm Mekaniska Verkstad och Varf as subcontractor for hull and machinery. Gotland, officially rated as a flygplankryssare, was launched on 14 September 1933 and commissioned the following December, eight years after presentation of the original plan.

As completed, her particulars were:

Displacement: 4750t standard, 5500t full load
Dimensions: 437ft 6in oa x 50ft 7in x 16ft 6in (mean), 18ft (max)
Machinery: 2 sets geared turbines, 4 boilers, 2 shafts, 33,000shp = 27.5kts
(27.53kts at 32,768shp on trials). Oil 760t normal, 880t max, 4000nm at 12kts
Armour: 1.125-2in deck and turrets, 2in conning tower, 1.125—2in
bulkheads, uptakes and hoists
Armament: six 6in (2 x 2,2 x 1), four 3in/60 AA (1 x 2,2 x 1), four 25mm MG;
six 21 in TT (2 x 3), 80-100 mines
Aircraft: 1 catapult, 11 aircraft max
Complement: 449

Gotland's equipment had a distinctly international flavour; there was even a brief possibility that her catapult might have been American. Acting on instructions from his government, the Swedish naval attaché in Washington, Commander Erik D Torén, on 16 December 1929 addressed a request to Captain A V Johnson, Director of Naval
Intelligence, for information about catapults and where they might be purchased in the United States. Catapults were needed for the cruiser of 'about 5000 tons' soon to be laid down.
The request was passed on to Rear Admiral William A Moffett, chief of the Bureau of Aeronautics, who pointed out that the only American manufacturer of catapults was the US government. However, Moffett was quite amenable to selling surplus Type A Mark I compressed air catapults that had been removed from Omaha class cruisers. He put the purchase price of such a catapult at $20,000, including cost of overhaul, and forwarded the recommendation to the General Board. Its members did not see things in quite
the same way and instructed Johnson to reject the request, which he did in a 20 January 1930 letter to Torén. Johnson informed the Swedish attaché that 'the catapults at present in use in the United States Navy are of Government design and manufacture, and it is not considered advisable to make them available to foreign governments. There are no commercial firms in the United States engaged in the manufacture of catapults'.
Thus balked, Gotland's builders turned to Germany's Ernst Heinkel Flugzeugewerke GmbH, which had been a pioneer in catapult development. Heinkel had sold some catapults abroad in addition to starting to equip the German Navy, and was glad to have the Swedish order, which was contracted on 21 April 1933. As installed on Gotland, the catapult was a compressed air expanding type, 49ft 9in long when stowed and extending to 65ft 6in for launching.
Gotland's fire-control equipment was also of German manufacture, while all the guns were made by Bofors. The turreted 6in guns could elevate to 60 degrees for AA use; the casemated guns abreast the bridge were, of course, far more constricted in both arc of train and elevation.
From her bow to a little bit aft of amidships, Gotland had the appearance of a normal, albeit somewhat stout, cruiser. Aft of the second 6in turret she became an aviation vessel, with a centreline catapult immediately forward of a long seaplane-carrying and handling deck. There was a heavy-duty crane right aft. Eight aircraft could be
accommodated on the deck, with stowage space for three more below. Aircraft were brought to the catapult on three fore-and-aft rails, each seaplane mounted on an individual electrically powered trolley; launchings could be accomplished at two-minute intervals. For seaplane recovery in less than calm seas, Gotland was equipped with a släpsegel (drag sail), the Swedish version of a Hein mat. It was trailed from the stern and aircraft were disengaged from it by the stern crane.
Gotland never carried the number of aircraft she was fitted to accommodate because of budgetary restrictions, and those she did employ were not embarked until several months after her commissioning. They were British Hawker Ospreys, two-place biplane reconaissance-fighters, which saw service in the Royal Navy both as capital ship and cruiser floatplanes and, with wheel undercarriages, aboard carriers. The Osprey was a 'navalised' version of the versatile Hart, which the Swedes had used in developing their
dive bombing techniques. Four Ospreys were ordered from Hawker Aircraft Ltd in 1933, with two more subsequently ordered. The first four arrived on 2 September 1934 and the others on 17 July 1936. Although constructed in Britain, the Swedish machines were given 600hp British Nohab Mercury II radiais built in Sweden under licence in place of the usual in-line Rolls-Royce engines. Gotland's Ospreys were given the Swedish type designation S.9 and bore serial numbers 401 to 406.

Prior to the outbreak of the Second World War, Gotland made a number of foreign cruises; after the war began she and her aircraft were employed in neutrality patrol in the Baltic, the Skaggerak and the Kattegat, also serving as a training ship. By this time her value as an aviation vessel was at an end, primarily because a narrow sea such as the Baltic could now be completely dominated by land-based aircraft greatly superior in performance and range to her floatplanes. Her Ospreys, one of which was lost with its
crew in an operational accident in January 1940, were hopelessly outmoded, their replacement impossible, and their store of spare parts diminishing.

Nevertheless, Gotland did perform one vital service: on 20 May 1941, while on passage to Gothenburg on Sweden's west coast, she sighted Bismarck and Prinz Eugen. This information was passed by friendly Swedish officers to the British naval attaché and was the first report the Admiralty received indicating that the German ships were on their way to the Atlantic.

Beginning in late 1943, Gotland was transformed from aircraft vessel to AA vessel. The catapult, crane and all other aviation equipment were removed; what had been the aircraft deck was extended over the former catapult well and eight 40mm/60 AA guns were placed on it in four twin mounts, supplemented by two 25mm/70 AA machine guns. The added armament increased her complement to 543 by the time the vessel reentered service in April 1944. Her Ospreys were transferred to harbour bases, where the last of them served until 2 December 1947.
Gotland resumed her foreign cruising after the war, until 1954, when she again underwent reconstruction. Her new guise was as a training and fighter-direction vessel, to which end her 6in casemate guns were removed, along with all the AA guns except two 25mm, and she was rearmed with a homogeneous suite of thirteen 40mm/40 AA guns in four twin and five single mounts. Searchlights were removed in favour of an illuminating-rocket launcher and radar fire-control was installed. Complement was reduced to 401. She resumed service in 1955.
Except for one cruise along the coast of west Africa in 1956, Gotland remained in home waters after her refit. Her days were numbered; in spite of a further refit that included improved fire-control and search radars, plus sonar, all of British manufacture, she was stricken on 1 July 1960, sold on 1 April 1962 and broken up at Ystad in 1963. For many years, Jane's Fighting Ships persisted in describing Gotland as a 'well-conceived and exceedingly useful type of warship'. This may have been true in 1926, when the original design was undertaken, but her usefulness as an aviation vessel was seriously eroded during the eight years it took to get her into the water, and continued even more rapidly from then to the outbreak of the Second World War. By 1939 technological advances in aviation had made the shipboard floatplane superfluous for naval war in such a narrow sea as the Baltic; in fact, the Ospreys were practically obsolete the day they were delivered.
Gotland also suffered from the attempt to achieve three ships in one hull. The results of this parsimony are plain: scaling down the original design to meet an inflexible financial limit led to a less efficient gunnery arrangement, and continued stringency denied the vessel her full complement of aircraft. However, even had Gotland been built to the original design and given a full aerial contingent, her loss of value as an aviation vessel was inevitable. This points to a problem that has, until fairly recently, plagued hybrid schemes, but which many designers nevertheless failed to recognise: because aircraft had a much shorter technological life than warships, a hybrid could lose much of its effectiveness long before the ship itself was ready for the scrapper's torch.