The Short N.1B Shirl was a British single-seat
biplane
A biplane is a fixed-wing aircraft with two main wings stacked one above the other. The first powered, controlled aeroplane to fly, the Wright Flyer, used a biplane wing arrangement, as did many aircraft in the early years of aviation. While ...
, intended to carry heavy
torpedo
A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, and with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, su ...
es from early
aircraft carrier
An aircraft carrier is a warship that serves as a seagoing airbase, equipped with a full-length flight deck and facilities for carrying, arming, deploying, and recovering aircraft. Typically, it is the capital ship of a fleet, as it allows a ...
s late in
World War I
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...
. It met its specifications but planned production was ended with the
Armistice of 1918. The design was developed further for an attempt to cross the Atlantic nonstop for the first time, but this was not successful.
Development
The first shipborne
torpedo bomber
A torpedo bomber is a military aircraft designed primarily to attack ships with aerial torpedoes. Torpedo bombers came into existence just before the First World War almost as soon as aircraft were built that were capable of carrying the weight ...
, the
Sopwith Cuckoo
The Sopwith T.1 Cuckoo was a British biplane torpedo bomber used by the Royal Naval Air Service (RNAS), and its successor organization, the Royal Air Force (RAF). The T.1 was the first landplane specifically designed for carrier operations, bu ...
had been well received, but was unable to carry the
Royal Navy
The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against F ...
's 1,423 lb (645 kg) Mark VIII torpedo that was required to destroy the largest warships. The
Admiralty
Admiralty most often refers to:
*Admiralty, Hong Kong
*Admiralty (United Kingdom), military department in command of the Royal Navy from 1707 to 1964
*The rank of admiral
*Admiralty law
Admiralty can also refer to:
Buildings
* Admiralty, Traf ...
issued a Specification (N.1B) in late 1917, for an aircraft that could carry this torpedo, and
Short Brothers
Short Brothers plc, usually referred to as Shorts or Short, is an aerospace company based in Belfast, Northern Ireland. Shorts was founded in 1908 in London, and was the first company in the world to make production aeroplanes. It was particu ...
and
Blackburn
Blackburn () is an industrial town and the administrative centre of the Blackburn with Darwen borough in Lancashire, England. The town is north of the West Pennine Moors on the southern edge of the Ribble Valley, east of Preston and north-n ...
submitted proposals, Short's with the Shirl and Blackburn with the
Blackburd. Both manufacturers were asked to provide three prototypes, using the 385 hp (290 kW)
Rolls-Royce Eagle
The Rolls-Royce Eagle was the first aircraft engine to be developed by Rolls-Royce Limited. Introduced in 1915 to meet British military requirements during World War I, it was used to power the Handley Page Type O bombers and a number of oth ...
VIII water-cooled engine.
The Shirl was a two-bay biplane with
foldable fabric-covered wings, without stagger and of equal span, carrying two pairs of
aileron
An aileron (French for "little wing" or "fin") is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll (or movement around ...
s. The fuselage was rectangular in cross-section and
plywood
Plywood is a material manufactured from thin layers or "plies" of wood veneer that are glued together with adjacent layers having their wood grain rotated up to 90 degrees to one another. It is an engineered wood from the family of manufactured ...
-covered, in anticipation of ditching at the end of the mission, since deck landing was not yet practicable. The split-axle
undercarriage
Undercarriage is the part of a moving vehicle that is underneath the main body of the vehicle. The term originally applied to this part of a horse-drawn carriage, and usage has since broadened to include:
*The landing gear of an aircraft.
*The ch ...
could be jettisoned for the same situation. The engine was cooled with a honeycomb radiator immediately behind a two-blade propeller.
Operational history
After initial tests, the first Shirl was given slight sweepback to allow for a shift in the centre of gravity caused by the addition of flotation bags. The undercarriage was also modified: the early single-axle version was jettisoned after takeoff, to allow for torpedo release and ditching, but now, with a split-axle, the torpedo or the undercarriage could be released separately or not at all. The new undercarriage had a pair of skids, each with a pair of wheels. With this arrangement the first aircraft satisfactorily underwent ditching trials in July 1918. This aircraft briefly used a four-bladed propeller, but soon reverted to the original two-bladed airscrew.
![Short Shirl at Grain](https://upload.wikimedia.org/wikipedia/commons/1/10/Short_Shirl_at_Grain.jpg)
The second Shirl had larger ailerons and no tailplane incidence adjustment, which made it hard to trim for flight, both with and without the torpedo. The third and final aircraft, delivered in December 1918, regained tailplane adjustment and had a further revised undercarriage.
Trials showed that the aircraft could deliver the torpedo, though it lacked the Cuckoo's evasive agility, after the burden of the torpedo was relieved. An order for 100 was placed, and quotations for more invited; but in early 1919 the Navy decided not to go ahead, ordering more Cuckoos instead.
The Shirl was regarded as a stable (in civilian life a virtue) aircraft with good fuel economy and weightlifting abilities. Mail-carrying was seen as a possible way of exploiting these characteristics, and the third Shirl was fitted with a large plywood container in the torpedo bay. A number of trial flights were made, but no commercial service followed.
Variants
Because of its weightlifting ability and fuel economy, the Shirl was considered the basis for a long-range aircraft to vie for the ''
Daily Mail
The ''Daily Mail'' is a British daily middle-market tabloid newspaper and news websitePeter Wilb"Paul Dacre of the Daily Mail: The man who hates liberal Britain", ''New Statesman'', 19 December 2013 (online version: 2 January 2014) publish ...
''
£10,000 prize for the first heavier-than-air transatlantic flight. For this attempt Short Brothers built a heavily revised Shirl, nicknamed the ''Shamrock''. It had its span increased by 10 ft 2 in (3.1 m) to 62 ft 2 in (18.95 m) with a three-bay wing, giving a wing area of 1,015 ft
2 (94.3 m
2). Empty weight increased by 662 lb (300 kg) to 3,962 lb (1,798 kg). A second seat, placed staggered side by side for the navigator was provided. A very large tubular fuel tank attached to the torpedo rack increased the total fuel load to 435 Imp gal (1,980 L) which would have given a 3,200 mi (5,120 km) still-air range (or 40 hours at 80 mph (128 km/h)). Very surprisingly, an East-West flight was chosen, very much against the prevailing winds and something not achieved until the flight of the
Junkers W.33 ''Bremen'' in April 1928. The
Curragh
The Curragh ( ; ga, An Currach ) is a flat open plain of almost of common land in County Kildare. This area is well known for Irish horse breeding and training. The Irish National Stud is located on the edge of Kildare town, beside the ...
plain in Ireland was chosen as the departure point, but the ''Shamrock'' never reached that far, ditching in the
Irish Sea
The Irish Sea or , gv, Y Keayn Yernagh, sco, Erse Sie, gd, Muir Èireann , Ulster-Scots: ''Airish Sea'', cy, Môr Iwerddon . is an extensive body of water that separates the islands of Ireland and Great Britain. It is linked to the Ce ...
due to engine failure, on the way to Ireland on 18 April 1919. The aircraft was recovered and might have made another attempt, but in July 1919
Alcock and Brown
British aviators John Alcock and Arthur Brown made the first non-stop transatlantic flight in June 1919. They flew a modified First World War Vickers Vimy bomber from St. John's, Newfoundland, to Clifden, County Galway, Ireland. The Secretary ...
won the prize in the
Vickers Vimy
The Vickers Vimy was a British heavy bomber aircraft developed and manufactured by Vickers Limited. Developed during the latter stages of the First World War to equip the Royal Flying Corps (RFC), the Vimy was designed by Reginald Kirshaw "Rex" ...
, flying West to East.
Specifications (standard Shirl)
The name
Shirl is not a common English word. The
Oxford English Dictionary
The ''Oxford English Dictionary'' (''OED'') is the first and foundational historical dictionary of the English language, published by Oxford University Press (OUP). It traces the historical development of the English language, providing a com ...
gives four meanings. Two of these, "shrill" and "rough", regarding hair are very old and seem to have fallen out of use in Elizabethan times. Two usages remained extant at the beginning of the 20th century: "a trimming" (of hair, wool etc.) and a "slide on ice". Both are given as dialect, though the first was not always so. The second is a northern usage. Either might perhaps describe a torpedo attack; the Short family was from the north of England.
See also
References
Notes
Bibliography
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External links
{{Short Brothers aircraft
1910s British bomber aircraft
Shirl
Single-engined tractor aircraft
Biplanes
Aircraft first flown in 1918