Avro Canada Orenda
Encyclopedia
The Avro Canada TR.5 Orenda was the first production jet engine
from Avro Canada
's Gas Turbine Division. Similar to other early jet engines in design, like the Rolls-Royce Avon
or General Electric J47
, the Orenda nevertheless outperformed its rivals in most ways, and the Orenda-powered Canadair Sabres were among the fastest of all first generation jet fighters. Over 4,000 Orendas of various marks were delivered during the 1950s, Avro's greatest engine success.
(RCAF) placed an order with Avro Canada for a new night/all-weather fighter
. To power the design, Avro decided to build their own engines. Avro had recently purchased Turbo Research, a former crown corporation set up in Leaside
, Toronto
, to develop jet engines.
Turbo Research was in the midst of designing their first engine, the 3000 lbf (13.3 kN) TR.4 Chinook
, which could easily be scaled up for the new fighter design. It was decided to continue working on the Chinook to gain experience even though they had no intention of producing it.
As work on the Chinook continued, Avro's newly christened Gas Turbine Division started work on the larger 6000 lbf (26.7 kN) thrust design needed for the RCAF contract. Winnett Boyd
started detailed design in autumn 1946, and a formal contract was received in April 1947. The only major change was the addition of a tenth compressor stage of stainless steel, and changing the third stage from aluminum to steel as well. The design work was completed on 15 January 1948, just prior to the first run of the Chinook on 17 March 1948. During the design Joseph Lucas
of the UK was contracted to help with the combustion design, which led to a slight delay as they recommended using a longer combustion chamber than originally designed. The resulting TR-5 was named "Orenda", an Iroquois
word meaning "Tribal Soul on the Right Path".
Given the experience of the Chinook, and the fact that the two designs were similar in many ways, progress on the Orenda was rapid. Parts started arriving in 1948, and the first engine was completed and run for the first time on 8 February 1949. Avro was so confident of the design that they invited high ranking officials from the RCAF and Canadian government to witness this very first test, which went off without a hitch after fixing a minor electrical problem. Within two months the engine had already passed 100 hours of running time, and on 10 May had reached its design thrust of 6000 lbf (26.7 kN). At the time, it was the most powerful jet engine in the world, although it held this record only briefly until the Rolls Royce Avon RA.3 was introduced the next year.
By 1 July it had passed 500 hours, and had run for 477 of these before requiring a rebuild. In September it was on its way to 1,000 hours when a technician's lab coat was sucked into the engine, complete with a set of razor blades in his pocket. From then on testing was carried out with a set of metal rings in the intake to avoid ingesting foreign objects. After repairing the damage the engine returned to testing, now joined by two further examples of the Orenda 1. Together they passed a total of 2,000 hours by 10 February 1950. By this point a problem with fatigue cracks in the seventh and eighth stages had become apparent, which required them to be redesigned and made much thicker. This solved the problem, and by July they had passed 3,000 hours.
Flight testing started with a converted Avro Lancaster
, FM209
, one of the many Mk.10's built at the Victory Aircraft
(now Avro) plants during the war. The two outboard Merlin engines were replaced with the Orendas, and the new aircraft took to the sky on 10 July. Avro test pilots had much fun flying the aircraft across Lake Ontario
to the Buffalo, New York
area, where they were able to easily outperform the P-47 Thunderbolt
's of the Air National Guard
that were sent to investigate. In one incident at an airshow, all four engines were turned off by mistake, but the Orenda's quick start time allowed them to save the day. The aircraft ran up 500 hours by July 1954, when this portion of flight testing ended; it was destroyed in a hangar fire on 24 July 1956.
and flown on 20 June 1952, with a squadron of pre-production Mk.2 aircraft entering RCAF service on 17 October. The Orenda 3 was similar, but had a number of modifications to allow it to be mounted in the Sabre in place of the J47. One example was produced and sent to North American Aviation
.
The first real production model was the Orenda 8, which was the powerplant of the CF-100 Mk.3. This model was first flown in September 1952 and entered service in 1953. This was soon followed by the Orenda 9 powered Mk.4 that flew on 11 October 1952, and then by the rocket-armed Mk.4A with the 7400 lbf (32.9 kN) Orenda 11. The Orenda 11 demanded higher airflow through the engine, and featured a second turbine stage to power the more powerful compressor. The 11 would be the primary production version for the CF-100, powering the Mk.4A and all future versions, with over 1,000 engines produced.
While work on the CF-100 continued the RCAF also started looking at a new day fighter
, eventually selecting the Sabre. A single Sabre 3 was built with the Orenda 4 engine, with performance similar to the US models. Production then turned to the Sabre 5 with the Orenda 18, and then to the Sabre 6 with the Orenda 11-derived 7275 lbf (32,360.8 N) thrust Orenda 14. The resulting Sabre was both lighter and more powerful than its J47 powered counterparts, and went on to set a number of air speed records. Most notable among these was Jacqueline Cochran
's supersonic flight in the sole Sabre 3, which Canadair lent to her for the effort. Canadair built 1,815 Sabres in total, 937 of these equipped with Orendas. Several examples, notably one at Boeing
, serving into the 1970s.
The engine was so successful that the Gas Turbine Division was renamed Orenda Engines when Hawker Siddeley reorganized their Canadian operations in 1955.
By 1953 the Orenda was planned to have been joined by an engine in the 10000 lbf (44.5 kN) thrust range, the Waconda.
At the front was the compressor section, containing the ten-stage compressor housed in a tapering magnesium alloy shell. The shell was machined with grooves that held the stators. At the front of the compressor was an intake fairing with a prominent "nose cone" containing the front main bearing. Four guide vanes held the cone in place, with a power takeoff shaft running inside one of them to power the top-mounted accessories section. The nose cone also held the electric starter motor, which acted as a generator once the engine was up and running. The engines used on the CF-100 also contained a uniquely Canadian invention, two prominent winglettes at the very front that sprayed alcohol into the intake as a de-icing system. The CF-100 versions also mounted the debris cage, mentioned earlier.
The compressor had ten axial stages of mixed steel and aluminum construction. In the original Orenda 8, 9 and 10's this operated at a 5.5:1 compression ratio
, compared to about 3.5 for wartime designs. The hub consisted of three aluminum disks carrying the first nine stages, and a steel disk bolted onto the end carrying the tenth. The central casing held the power shaft and was made from magnesium alloy. Around it were the six flame cans. The turbine was made of solid Inconel blades attached to an austenitic steel hub. The blades were air cooled by bleeding off compressed air from the fifth compressor stage and piping it to the turbine face, the six pipes lying between the flame cans. The exhaust section consisted of welded steel sheeting.
The Orenda 10 produced 6500 lbf (28,913.4 N) at 7800 rpm. It was 10 in 1 in (3.07 m) long, and 3 in 6 in (1.07 m) wide, and weighed 1141 lb (517.5 kg).
Jet engine
A jet engine is a reaction engine that discharges a fast moving jet to generate thrust by jet propulsion and in accordance with Newton's laws of motion. This broad definition of jet engines includes turbojets, turbofans, rockets, ramjets, pulse jets...
from Avro Canada
Avro Canada
Commonly known as Avro Canada, this company started in 1945 as an aircraft plant and became within thirteen years the third-largest company in Canada, one of the largest 100 companies in the world, and directly employing over 50,000...
's Gas Turbine Division. Similar to other early jet engines in design, like the Rolls-Royce Avon
Rolls-Royce Avon
|-See also:-Bibliography:* Gunston, Bill. World Encyclopaedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9-External links:**** a 1955 Flight article on the development of the Avon...
or General Electric J47
General Electric J47
|-Specifications :-Nuclear-powered version – The X39:In the 1950s, interest in the development of nuclear-powered aircraft led GE to experiment with two nuclear-powered gas turbine designs, one based on the J47, and another new and much larger engine called the X211.The design based on the J47...
, the Orenda nevertheless outperformed its rivals in most ways, and the Orenda-powered Canadair Sabres were among the fastest of all first generation jet fighters. Over 4,000 Orendas of various marks were delivered during the 1950s, Avro's greatest engine success.
Development
The Orenda design started in the summer of 1946 when the Royal Canadian Air ForceRoyal Canadian Air Force
The history of the Royal Canadian Air Force begins in 1920, when the air force was created as the Canadian Air Force . In 1924 the CAF was renamed the Royal Canadian Air Force and granted royal sanction by King George V. The RCAF existed as an independent service until 1968...
(RCAF) placed an order with Avro Canada for a new night/all-weather fighter
Night fighter
A night fighter is a fighter aircraft adapted for use at night or in other times of bad visibility...
. To power the design, Avro decided to build their own engines. Avro had recently purchased Turbo Research, a former crown corporation set up in Leaside
Leaside
Leaside is a neighbourhood in Toronto, Ontario, Canada. The area takes its name from William Lea and the Lea family, who settled there in the early years of the nineteenth century. The area first developed as farmland along with Toronto through the nineteenth century. It was incorporated as a...
, Toronto
Toronto
Toronto is the provincial capital of Ontario and the largest city in Canada. It is located in Southern Ontario on the northwestern shore of Lake Ontario. A relatively modern city, Toronto's history dates back to the late-18th century, when its land was first purchased by the British monarchy from...
, to develop jet engines.
Turbo Research was in the midst of designing their first engine, the 3000 lbf (13.3 kN) TR.4 Chinook
Avro Canada Chinook
The Avro Canada TR.4 Chinook was Canada's first turbojet engine, designed by Turbo Research and manufactured by A.V. Roe Canada Ltd. Named for the warm Chinook wind that blows in the Rocky Mountains, only three Chinooks were built and none were used operationally...
, which could easily be scaled up for the new fighter design. It was decided to continue working on the Chinook to gain experience even though they had no intention of producing it.
As work on the Chinook continued, Avro's newly christened Gas Turbine Division started work on the larger 6000 lbf (26.7 kN) thrust design needed for the RCAF contract. Winnett Boyd
Winnett Boyd
Winnett Boyd is a Canadian engineer who made major contributions to the development of the jet engine and nuclear reactor design.-Early life and education:...
started detailed design in autumn 1946, and a formal contract was received in April 1947. The only major change was the addition of a tenth compressor stage of stainless steel, and changing the third stage from aluminum to steel as well. The design work was completed on 15 January 1948, just prior to the first run of the Chinook on 17 March 1948. During the design Joseph Lucas
Lucas Industries plc
Lucas Industries plc was a famous British manufacturer of components for the motor industry and aerospace industry. It was based in Birmingham. It was listed on the London Stock Exchange and was once a constituent of the FTSE 100 Index...
of the UK was contracted to help with the combustion design, which led to a slight delay as they recommended using a longer combustion chamber than originally designed. The resulting TR-5 was named "Orenda", an Iroquois
Iroquoian languages
The Iroquoian languages are a First Nation and Native American language family.-Family division:*Ruttenber, Edward Manning. 1992 [1872]. History of the Indian tribes of Hudson's River. Hope Farm Press....
word meaning "Tribal Soul on the Right Path".
Given the experience of the Chinook, and the fact that the two designs were similar in many ways, progress on the Orenda was rapid. Parts started arriving in 1948, and the first engine was completed and run for the first time on 8 February 1949. Avro was so confident of the design that they invited high ranking officials from the RCAF and Canadian government to witness this very first test, which went off without a hitch after fixing a minor electrical problem. Within two months the engine had already passed 100 hours of running time, and on 10 May had reached its design thrust of 6000 lbf (26.7 kN). At the time, it was the most powerful jet engine in the world, although it held this record only briefly until the Rolls Royce Avon RA.3 was introduced the next year.
By 1 July it had passed 500 hours, and had run for 477 of these before requiring a rebuild. In September it was on its way to 1,000 hours when a technician's lab coat was sucked into the engine, complete with a set of razor blades in his pocket. From then on testing was carried out with a set of metal rings in the intake to avoid ingesting foreign objects. After repairing the damage the engine returned to testing, now joined by two further examples of the Orenda 1. Together they passed a total of 2,000 hours by 10 February 1950. By this point a problem with fatigue cracks in the seventh and eighth stages had become apparent, which required them to be redesigned and made much thicker. This solved the problem, and by July they had passed 3,000 hours.
Flight testing started with a converted Avro Lancaster
Avro Lancaster
The Avro Lancaster is a British four-engined Second World War heavy bomber made initially by Avro for the Royal Air Force . It first saw active service in 1942, and together with the Handley Page Halifax it was one of the main heavy bombers of the RAF, the RCAF, and squadrons from other...
, FM209
United Kingdom military aircraft serials
In the United Kingdom to identify individual aircraft, all military aircraft are allocated and display a unique serial number. A unified serial number system, maintained by the Air Ministry , and its successor the Ministry of Defence , is used for aircraft operated by the Royal Air Force , Fleet...
, one of the many Mk.10's built at the Victory Aircraft
Victory Aircraft
Victory Aircraft Limited was a Canadian manufacturing company that, during the Second World War, built mainly British-designed aircraft under license. It acted as a shadow factory, safe from the reach of German bombers....
(now Avro) plants during the war. The two outboard Merlin engines were replaced with the Orendas, and the new aircraft took to the sky on 10 July. Avro test pilots had much fun flying the aircraft across Lake Ontario
Lake Ontario
Lake Ontario is one of the five Great Lakes of North America. It is bounded on the north and southwest by the Canadian province of Ontario, and on the south by the American state of New York. Ontario, Canada's most populous province, was named for the lake. In the Wyandot language, ontarío means...
to the Buffalo, New York
Buffalo, New York
Buffalo is the second most populous city in the state of New York, after New York City. Located in Western New York on the eastern shores of Lake Erie and at the head of the Niagara River across from Fort Erie, Ontario, Buffalo is the seat of Erie County and the principal city of the...
area, where they were able to easily outperform the P-47 Thunderbolt
P-47 Thunderbolt
Republic Aviation's P-47 Thunderbolt, also known as the "Jug", was the largest, heaviest, and most expensive fighter aircraft in history to be powered by a single reciprocating engine. It was heavily armed with eight .50-caliber machine guns, four per wing. When fully loaded, the P-47 weighed up to...
's of the Air National Guard
Air National Guard
The Air National Guard , often referred to as the Air Guard, is the air force militia organized by each of the fifty U.S. states, the commonwealth of Puerto Rico, the territories of Guam and the U.S. Virgin Islands, and the District of Columbia of the United States. Established under Title 10 and...
that were sent to investigate. In one incident at an airshow, all four engines were turned off by mistake, but the Orenda's quick start time allowed them to save the day. The aircraft ran up 500 hours by July 1954, when this portion of flight testing ended; it was destroyed in a hangar fire on 24 July 1956.
Production
The Orenda 2 was the first production model, passing its qualification tests in February 1952. This version showed additional cracking in the ninth stage, and had to be strengthened like the earlier model. Even before being qualified, the engine had been fitted to the Avro CF-100Avro CF-100
The Avro Canada CF-100 Canuck was a Canadian jet interceptor/fighter serving during the Cold War both in NATO bases in Europe and as part of NORAD. The CF-100 was the only Canadian-designed fighter to enter mass production, serving primarily with the RCAF/CAF and in small numbers in Belgium...
and flown on 20 June 1952, with a squadron of pre-production Mk.2 aircraft entering RCAF service on 17 October. The Orenda 3 was similar, but had a number of modifications to allow it to be mounted in the Sabre in place of the J47. One example was produced and sent to North American Aviation
North American Aviation
North American Aviation was a major US aerospace manufacturer, responsible for a number of historic aircraft, including the T-6 Texan trainer, the P-51 Mustang fighter, the B-25 Mitchell bomber, the F-86 Sabre jet fighter, the X-15 rocket plane, and the XB-70, as well as Apollo Command and Service...
.
The first real production model was the Orenda 8, which was the powerplant of the CF-100 Mk.3. This model was first flown in September 1952 and entered service in 1953. This was soon followed by the Orenda 9 powered Mk.4 that flew on 11 October 1952, and then by the rocket-armed Mk.4A with the 7400 lbf (32.9 kN) Orenda 11. The Orenda 11 demanded higher airflow through the engine, and featured a second turbine stage to power the more powerful compressor. The 11 would be the primary production version for the CF-100, powering the Mk.4A and all future versions, with over 1,000 engines produced.
While work on the CF-100 continued the RCAF also started looking at a new day fighter
Day fighter
A day fighter is a fighter aircraft equipped only to fight during the day. More specifically, it refers to a multi-purpose aircraft that does not include equipment for fighting at night , although it is sometimes used to refer to some interceptors as well.Examples of planes that were classified as...
, eventually selecting the Sabre. A single Sabre 3 was built with the Orenda 4 engine, with performance similar to the US models. Production then turned to the Sabre 5 with the Orenda 18, and then to the Sabre 6 with the Orenda 11-derived 7275 lbf (32,360.8 N) thrust Orenda 14. The resulting Sabre was both lighter and more powerful than its J47 powered counterparts, and went on to set a number of air speed records. Most notable among these was Jacqueline Cochran
Jacqueline Cochran
Jacqueline Cochran was a pioneer American aviator, considered to be one of the most gifted racing pilots of her generation...
's supersonic flight in the sole Sabre 3, which Canadair lent to her for the effort. Canadair built 1,815 Sabres in total, 937 of these equipped with Orendas. Several examples, notably one at Boeing
Boeing
The Boeing Company is an American multinational aerospace and defense corporation, founded in 1916 by William E. Boeing in Seattle, Washington. Boeing has expanded over the years, merging with McDonnell Douglas in 1997. Boeing Corporate headquarters has been in Chicago, Illinois since 2001...
, serving into the 1970s.
The engine was so successful that the Gas Turbine Division was renamed Orenda Engines when Hawker Siddeley reorganized their Canadian operations in 1955.
By 1953 the Orenda was planned to have been joined by an engine in the 10000 lbf (44.5 kN) thrust range, the Waconda.
Design
The Orenda was fairly conventional in layout, built in three main parts; compressor, combustion area, and turbine/exhaust.At the front was the compressor section, containing the ten-stage compressor housed in a tapering magnesium alloy shell. The shell was machined with grooves that held the stators. At the front of the compressor was an intake fairing with a prominent "nose cone" containing the front main bearing. Four guide vanes held the cone in place, with a power takeoff shaft running inside one of them to power the top-mounted accessories section. The nose cone also held the electric starter motor, which acted as a generator once the engine was up and running. The engines used on the CF-100 also contained a uniquely Canadian invention, two prominent winglettes at the very front that sprayed alcohol into the intake as a de-icing system. The CF-100 versions also mounted the debris cage, mentioned earlier.
The compressor had ten axial stages of mixed steel and aluminum construction. In the original Orenda 8, 9 and 10's this operated at a 5.5:1 compression ratio
Compression ratio
The 'compression ratio' of an internal-combustion engine or external combustion engine is a value that represents the ratio of the volume of its combustion chamber from its largest capacity to its smallest capacity...
, compared to about 3.5 for wartime designs. The hub consisted of three aluminum disks carrying the first nine stages, and a steel disk bolted onto the end carrying the tenth. The central casing held the power shaft and was made from magnesium alloy. Around it were the six flame cans. The turbine was made of solid Inconel blades attached to an austenitic steel hub. The blades were air cooled by bleeding off compressed air from the fifth compressor stage and piping it to the turbine face, the six pipes lying between the flame cans. The exhaust section consisted of welded steel sheeting.
The Orenda 10 produced 6500 lbf (28,913.4 N) at 7800 rpm. It was 10 in 1 in (3.07 m) long, and 3 in 6 in (1.07 m) wide, and weighed 1141 lb (517.5 kg).
Variants
- Orenda 1 - original prototype models, 6000 lbf (26.7 kN)
- Orenda 2 - first production model
- Orenda 8 - improved reliability, 6000 lbf (26.7 kN)
- Orenda 9 - improved thrust, 6500 lbf (28.9 kN), required some changes to the nacelles
- Orenda 10 - Orenda 9 adapted for the Sabre
- Orenda 11 - main production version for the CF-100, 7400 lbf (32.9 kN)
- Orenda 14 - similar to the 11, 7275 lbf (32.4 kN), used on both the CF-100 and Sabre
- Orenda 17 - combined the compressor from the 9 with the turbine of the 11, along with an afterburner 8490 lbf (37.8 kN) wet
External links
- Orenda, Avroland
- Lancaster FM-209, images of the Orenda installations
- Orenda-8