HMS Nairana () was a passenger ferry that was requisitioned by the Royal Navy (RN) as a seaplane carrier in 1917. She was laid down in Scotland in 1914 as TSS Nairana for the Australian shipping line Huddart Parker, but construction was suspended after the outbreak of the First World War. Following resumption of work, the ship was launched in 1915, and converted to operate wheeled aircraft from her forward flying-off deck, as well as floatplanes that were lowered into the water. She saw service during the war with the Grand Fleet, and in 1918–19 supported the British intervention in the Russian Civil War.
Nairana was returned to her former owners in 1921 and refitted in her original planned configuration, and spent the next 27 years ferrying passengers and cargo between Tasmania and Melbourne. She was twice struck by rogue waves in Bass Strait, and nearly capsized on both occasions. Nairana was the only Bass Strait ferry not requisitioned for military service in the Second World War, and so became the sole passenger ship with service to Tasmania during the conflict. She was laid up in 1948, wrecked in a storm three years later and scrapped in situ in 1953–54.
Background and description
Original design
In December 1913, negotiations between the Australian shipping line Huddart Parker and the British shipbuilders William Denny and Brothers began for a passenger ship with some cargo capacity to serve in the Australian coastal trade. The shipping line wanted a vessel that would improve on their earlier ferry Loongana, which had also been built by Denny's. Huddart Parker decided on a design that could carry of cargo on a draught of and could maintain for 12 hours. The ship was ordered on 22 January 1914, at a cost of £129,830, for delivery in May 1915. She was named Nairana, an Aboriginal Tasmanian name for the wedge-tailed eagle (Aquila audax).
Nairana was designed to accommodate 280 first-class and 112 second-class passengers, and had a crew of 26 officers, 42 crewmen and 25 stokers. She had an overall length of , a beam of , and a draught of . Designed to displace Nairana had tonnages of , 1,118 long tons DWT, and 3,311 tons Builder's Old Measurement.
The ship was launched 21 June 1915 at the Denny shipyard in Dumbarton, Scotland. The launch had been delayed nine months, after the British Government ordered that all construction workers be pulled from non-military vessels after the start of the First World War, and work had been resumed only to make her slipway available for warships. She remained at anchor for the next year and a half. The Royal Navy purchased her on 27 February 1917 for completion as a combined landplane and seaplane carrier. The price of £138,118 included the cost of conversion to her new role. The ship was nearly complete when requisitioned, although her propelling machinery was not yet installed. Consequently, only limited internal modifications, notably the addition of three large workshops, could be made.
Military configuration
HMS Nairana displaced in RN service. She was long overall, had a beam of , and a mean draught of . The ship was powered by two sets of Parsons geared steam turbines designed to produce a total of , each driving one three-bladed propeller. The turbines were powered by steam provided by six Babcock & Wilcox water-tube boilers at a working pressure of . On her sea trials, Nairana made and reached . She carried of coal which gave her a range of at a speed of . Her crew numbered 278, including 90 aviation personnel.
The ship was armed with four 40-calibre, 12-pounder 12 cwt quick-firing guns on single mounts. Two of these were mounted on the forecastle as low-angle guns, and the other two were mounted on the rear hangar roof as anti-aircraft guns. They fired projectiles at a muzzle velocity of ; this gave a maximum range of .
Nairana was fitted with a flying-off deck forward, intended for aircraft with wheeled undercarriages, and a prominent hangar aft. A massive latticework gantry crane protruded aft from the hangar roof and a twin-boom derrick forward were fitted to handle her aircraft. The smaller forward hangar was built under the ship's bridge and the aircraft were raised to the flight deck overhead by a lift, one of the first in the RN. The forward hangar could fit four single-seat fighters and the rear hangar had a capacity of four floatplanes. The ship could lower them into the water while steaming at and recover the floatplanes at . She carried of petrol for her aircraft.
During her service, Nairana carried Beardmore W.B.III, Fairey Campania, Short Type 184, and Sopwith Baby, Pup, and 2F1 Camel aircraft.