Short Empire
The Short Empire was a medium range four engined monoplane passenger and mail carrying flying boat, of the 1930s and 1940s, that flew between Britain and the British colonies in Africa, Asia and Australia as well as providing service between Bermuda and New York City. It was manufactured by Short Brothers and was developed in parallel with the Short Sunderland patrol bomber of World War II and the piggy-back Short Mayo Composite .
The origins of the Empire boats lay in an Air Ministry requirement for passenger and mail carriers that could provide air mail service to the colonies in Africa and Australia.
The Empire was officially known as the C-class by Imperial Airways and each aircraft operated by them was given 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 in commercial service, while the Royal Air Force, Royal Australian Air Force, Royal
New Zealand Air Force and briefly the Royal Canadian Air Force used them on military operations during the Second World War, particularly for anti-submarine patrol and transport duties.
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) and were powered by four 920 horsepower (690 kW) Bristol Pegasus radials.
The Short Empire was designed to operate along the Imperial Airways routes to South Africa and Australia, where no leg was much over 500 miles (800 km). After the design was finalized and production was started it was realized, with some pressure from the United States, 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 Atlantic crossing, a piggy-back approach was tried. Using the S.21 design (based on the S.23) as the carrier, with a smaller four-engined floatplane, the Short S.20, mounted on its back. Only a single example was built of the S.21 carrier aircraft, the Maia, and of the S.20 Mercury. Together they were known as the Short Mayo Composite. 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 the Mercury was limited to carrying mail, and no further development of this concept occurred in the UK.
The S.30 series were fitted with the more efficient, but lower power 890 horsepower (660 kW) Bristol Perseus sleeve valve engines and had a strengthened airframe allowing the take off weight to be increased to 46,000 pounds (21,000 kg), giving a range of 1,500 miles (2,400 km). 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 was for the aircraft to take off and once airborne take on extra fuel to an all up weight of 53,000 pounds (24,000 kg) giving a range of over 2,500 miles (4,000 km). The extra fuel did reduce the payload to 4,270 pounds (1,940 kg) against the 6,250 pounds (2,830 kg) 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 the same Pegasus to what had been fitted to the S.23
Initially, they were designed for a 40,500 lb gross weight but by 1939 aircraft were strengthened for 53,000 lb (24,000 kg)
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 1944 were regularly acrossing the Atlantic without resorting to in-flight refuelling, and with a reasonable cargo.
In addition to the C class flying boats three S.26 type were built as the "G class" and which 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 specifically designed to provide a regular trans-Atlantic service. They had a wing span of 134 feet (41 m) and a length of 101 feet (31 m).
In February 1937 Caledonia flew from Calshot to Alexandria, Egypt - some 2,500 miles (4,000 km) non-stop showing that Britain could move military materiel to its overseas bases. In 1937 Caledonia was flown experimentally from Foynes on the River Shannon west to Newfoundland while an American Sikorsky S-42 flew the opposite direction.
Caledonia took just over 15 hours (including a period looking for landing spot) flying at an altitude of 1,500 to 5,000 ft (460 to 1,500 m) to cover 1,993 miles (3,207 km) - an average speed of about 130 mph (210 km/h). The Sikorsky took about half an hour less flying, with the prevailing wind, at 10,000 ft (3,000 m). Several more survey flights of the Atlantic were made by Caledonia and Cambria. In August 1937, Cambria made the East-West flight in 14 hrs 24 min. In 1937 Cavalier was shipped to Bermuda and after assembly started a service to New York on 25 May 1937.
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.
The origins of the Empire boats lay in an Air Ministry requirement for passenger and mail carriers that could provide air mail service to the colonies in Africa and Australia.
The Empire was officially known as the C-class by Imperial Airways and each aircraft operated by them was given 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 in commercial service, while the Royal Air Force, Royal Australian Air Force, Royal
New Zealand Air Force and briefly the Royal Canadian Air Force used them on military operations during the Second World War, particularly for anti-submarine patrol and transport duties.
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) and were powered by four 920 horsepower (690 kW) Bristol Pegasus radials.
The Short Empire was designed to operate along the Imperial Airways routes to South Africa and Australia, where no leg was much over 500 miles (800 km). After the design was finalized and production was started it was realized, with some pressure from the United States, 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 Atlantic crossing, a piggy-back approach was tried. Using the S.21 design (based on the S.23) as the carrier, with a smaller four-engined floatplane, the Short S.20, mounted on its back. Only a single example was built of the S.21 carrier aircraft, the Maia, and of the S.20 Mercury. Together they were known as the Short Mayo Composite. 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 the Mercury was limited to carrying mail, and no further development of this concept occurred in the UK.
The S.30 series were fitted with the more efficient, but lower power 890 horsepower (660 kW) Bristol Perseus sleeve valve engines and had a strengthened airframe allowing the take off weight to be increased to 46,000 pounds (21,000 kg), giving a range of 1,500 miles (2,400 km). 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 was for the aircraft to take off and once airborne take on extra fuel to an all up weight of 53,000 pounds (24,000 kg) giving a range of over 2,500 miles (4,000 km). The extra fuel did reduce the payload to 4,270 pounds (1,940 kg) against the 6,250 pounds (2,830 kg) 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 the same Pegasus to what had been fitted to the S.23
Initially, they were designed for a 40,500 lb gross weight but by 1939 aircraft were strengthened for 53,000 lb (24,000 kg)
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 1944 were regularly acrossing the Atlantic without resorting to in-flight refuelling, and with a reasonable cargo.
In addition to the C class flying boats three S.26 type were built as the "G class" and which 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 specifically designed to provide a regular trans-Atlantic service. They had a wing span of 134 feet (41 m) and a length of 101 feet (31 m).
In February 1937 Caledonia flew from Calshot to Alexandria, Egypt - some 2,500 miles (4,000 km) non-stop showing that Britain could move military materiel to its overseas bases. In 1937 Caledonia was flown experimentally from Foynes on the River Shannon west to Newfoundland while an American Sikorsky S-42 flew the opposite direction.
Caledonia took just over 15 hours (including a period looking for landing spot) flying at an altitude of 1,500 to 5,000 ft (460 to 1,500 m) to cover 1,993 miles (3,207 km) - an average speed of about 130 mph (210 km/h). The Sikorsky took about half an hour less flying, with the prevailing wind, at 10,000 ft (3,000 m). Several more survey flights of the Atlantic were made by Caledonia and Cambria. In August 1937, Cambria made the East-West flight in 14 hrs 24 min. In 1937 Cavalier was shipped to Bermuda and after assembly started a service to New York on 25 May 1937.
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.