Short Empire

infobox Aircraft
name = Empire
type = Flying boat mail carrier
manufacturer = Short Brothers



caption = The BOAC Short 'C' Class flying boat G-AFBL "Cooee", at Rod El Faray, Egypt, c. 1942
designer =
first flight = 3 July 1936
introduced =
retired =
status =
primary user = Imperial Airways
more users =
produced =
number built = 42
unit cost =
developed from =
variants with their own articles =

The Short Empire was a passenger and mail carrying flying boat, of the 1930s and 1940s, which flew between Britain and British colonies in Africa, Asia and Australia. It was manufactured by Short Brothers and was the precursor to the more famous Short Sunderland of World War II. In the United States, its contemporary was the Sikorsky S-42.

Design and development

The origins of the Empire boats lay in an Air Ministry requirement for passenger and mail carriers that could service the colonies particularly to make the connection to Australia.

The Empire was officially known as the C-class and each aircraft was christened with a name beginning with C. The first aircraft, G-ADHL "Canopus", was completed in June 1936 and launched on 3 July. A total of 42 Empires were built, all at Short's Rochester factory.

Imperial Airways (and its successor BOAC), Qantas and TEAL operated the Short Empire.

The first series of the Short Empires, the S.23, could carry 5 crew, 17 passengers, and 4,480 lb (2,035 kg) of cargo at a maximum speed of 174 knots (320 km/h).

The Short Empire was designed to be operate along the Imperial Airways routes to South Africa and Australia, where no leg was much over 500 miles. After the design was finalized and production was started it was realized, with some pressure from the US, that it would be desirable to offer a similar service across the Atlantic.The range of the S.23 was less than that of the equivalent US Sikorsky "Clipper" flying boats and as such they could not provide a true trans-Atlantic service. Two boats ("Caledonia" and "Cambria") were lightened and given long range tanks and experimented with in flight refuelling so they could make the trip but that meant they could carry fewer passengers and cargo. In an attempt to manage the Altantic crossing a piggy-back approach was tried. Using a heavily modified S.23 design as the main carrier and a smaller four-engined floatplane design, the Short S.20, mounted on its back. Only a single example was built of a carrier aircraft, the S.21 ("Maia") and one S.20 ("Mercury") together known as the Short Mayo Composite [ [http://aerostories.free.fr/appareils/compopara/page14.html Robert Mayo – Short Aircraft Engineer's Concept ] ] A successful mid-air launch of Mercury was made in 1938, and it was to set a number of long distance records however a launch aircraft was required for both sides of the Atlantic and it was limited to carrying mail, and no further development of this concept occurred in the UK.

The S.30 series were fitted with the slightly more efficient, but lower powered 815 hp Bristol Perseus sleeve valve engines and had a strengthened airframe allowing the take off weight to be increased to 46,000 pounds and giving a range of 1,500 miles. "Cabot", "Caribou", "Clyde" and "Connemara" were fitted with in-flight refuelling equipment and extra fuel tanks so they could be used for a regular trans-atlantic airmail service. The idea behind this was for the aircraft to take off and once airborne take on extra fuel to an all up weight of 53,000 pounds giving a range of over 2,500 miles. The extra fuel did reduce the payload to 4,270 pounds against the 6,250 pounds of the standard craft. The refuelling was by three converted Handley Page Harrow bombers, one operating out of Ireland and two out of Newfoundland. The S.33 was a further follow-on to the S.30 with a later version of the Pegasus to what had been fitted to the S.23

While originally deemed unable to takeoff with sufficient fuel, wartime experiences at operating in overload resulted in the realization that the Empires could be flown at considerably higher weights than the very conservative estimates provided by Shorts and by late in the war were flying across the Atlantic without resorting to in-flight refuelling, and while still carrying a reasonable cargo.

In addition to the C class flying boats there were also three S.26 type built; these were known as the "G class" and had names starting with "G": "Golden Hind", "Golden Fleece" and "Golden Horn". They were considerably larger than the C class and benefited from improvements to hull design made after the finalization of the S.23 design but aside from a general resemblance were an entirely new design which had been intended for provide a regular trans-Atlantic service. They had a wing span of 134 ft (40.9 m) and a length of 101 ft. (30.9 m).

Variants

* S.21 : ("Maia") Carrier aircraft of the Short Mayo Composite
* S.23 : Passenger and mail flying-boat, powered by four 920-hp (686-kW) Bristol Perseus radial piston engines. 31 built.
* S.23M : Two S.23's were fitted with an ASV radar, and armed with guns and bombs.
* S.26 'G' Class Empire Passenger and mail flying-boat. Three built.
* S.26M 'G' Class armed VIP transport, modified from S.26.
* S.30 : Passenger and mail flying-boat, powered by four 890-hp (664-kW) Bristol Perseus radial piston engines, Derivative of S.23. Nine built.
* S.33 : Passenger and mail flying-boat, powered by four 920-hp (686-kW) Bristol Perseus radial piston engines. Derivative of S.23. Two built.

ervice

During the Second World War the UK-Australia route was stopped and a new route was established which ran from Sydney to Durban via Cairo. This was stopped after the loss of Singapore but restarted when the Japanese were ousted from Burma and Malaya.

List of aircraft

Operators

Civil Operators

;AUS
* Qantas;NZL
* TEAL;UK
* Imperial Airways
* BOAC

Military Operators

;AUS
* Royal Australian Air Force
** No. 11 Squadron RAAF
** No. 13 Squadron RAAF
** No. 20 Squadron RAAF
** No. 33 Squadron RAAF
** No. 41 Squadron RAAF;UK
* Royal Air Force
** No. 119 Squadron RAF

pecifications (Shorts S.23)

aircraft specifications
plane or copter?=plane
jet or prop?=prop

ref=The Encyclopedia of World Aircraft [Cite book
author=Donald, David(Editor)
authorlink =
|title=The Encyclopedia of World Aircraft
publisher=Aerospace Publishing
year=1997
id= ISBN 1-85605-375-X
crew=
capacity=
length main= 88 ft
length alt= 26.82m
span main= 114 ft
span alt= 34.75 m
height main= 31 ft 9¾ in
height alt= 9.70 m
area main= 1,500 ft²
area alt= 139.35 m²
airfoil=
empty weight main= 23,500 lb
empty weight alt= 10,659 kg
max takeoff weight main= 40,500 lb
max takeoff weight alt= 18,370 kg
more general=

engine (prop)=Bristol Pegasus
type of prop= radial engines
number of props=4
power main= 920 hp
power alt= 696 kW
power original=
max speed main= 200 mph
max speed alt= 322 km/h
range main= 760 miles
range alt= 1,223 km
ceiling main= 20,000 ft
ceiling alt= 6,100 m
more performance=
armament=
avionics=

ee also

aircontent
related=
* Short S.26
* Short Mayo Composite

similar aircraft=

lists=

see also=

References

* "BOAC At War" - Part 2 - Aeroplane Monthly - August 1975
* Sims, Phillip, "Adventurous Empires". Airlife Publishing, 2000. ISBN 1-84037-130-7
* [http://www.vectorsite.net/avsund.html#m1 Vector site development of Sunderland through Empire boats]
* cite book
last = Barnes C.H. & James D.N
first =
authorlink =
coauthors =
title =Shorts Aircraft since 1900
publisher =Putnam
date =
location =London (1989)
pages =560
url =
doi =
id = ISBN 0-85177-819-4

External links

* [http://airlines.afriqonline.com/airlines/538.htm T.E.A.L. Airline]
* [http://britishaircraft.co.uk/aircraftpage.php?ID=369 British Aircraft Directory entry]
* [http://www.jaapteeuwen.com/ww2aircraft/html%20pages/SHORT%20C-CLASS%20EMPIRE%20BOATS.htm British Aircraft of WW2]
* [http://www.century-of-flight.freeola.com/Aviation%20history/coming%20of%20age/flying%20boats/Short%20S-23%20Empire.htm Century of Flight entry]