The Daniel and Florence Guggenheim Memorial Lecture Civil Propulsion; the Last 50 Years
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ICAS2002 CONGRESS THE DANIEL AND FLORENCE GUGGENHEIM MEMORIAL LECTURE CIVIL PROPULSION; THE LAST 50 YEARS H.I.H. Saravanamuttoo Carleton University and GasTOPS Introduction on a train to get to that final destination; one of the common derogatory terms was “just off the This paper covers propulsion developments boat”. in the civil field over the last five decades. It is Train travel in North America was well notable that aircraft have displaced ships and developed with all major cities connected by railways for long distance passenger travel, and rail. The railway station was in the centre of all this could not have been achieved without the big cities and was surrounded by the business continuous development of the aircraft gas district; this is still the norm in Europe but has turbine. The paper traces propulsion not been true in North America for many years. developments from the end of the piston era Transcontinental trains were widely used and through the early turboprops and turbojets to the crossing the continent took several days. high bypass ratio turbofans of the present. Distances of 500-600 miles were often covered by overnight express trains. The idea of a one Travel Situation in 1952 day business trip from, say, Toronto to It is instructive to consider the situation in Montreal, was out of the question. 1952 before embarking on a study of propulsion Internal air transport in North America was developments over the last 50 years. Younger in its infancy and was virtually non existent in readers may be surprised to know that aviation other parts of the world. Aircraft such as the played only a very minor role in passenger DC-3 and Convair 240 were in use, with transportation at that time. passenger capacities of about 20-40 and very At the end of World War II Europe was limited range. A few airlines operated reduced to a very poor economic state and much Constellations, Stratocruisers and DC-6 on the effort was required to rebuild the infrastructure. Atlantic; the major airlines were Pan American Pre-war passenger liners were returned to and TWA. service, but the market now shifted from luxury Noting that Pan American have travel for the wealthy to large scale emigration disappeared and TWA are bankrupt, it is also from Europe to countries such as the US, interesting to consider who were the major Canada, Australia and South Africa. Many new players in the aircraft industry. In terms of long ships were built in the decade following the end haul aircraft the dominant companies were of WW II and the building of passenger ships Lockheed and Douglas, and for short haul was a major industry; the rapid and total decline Douglas, Martin and Convair. The principal of this industry certainly could not have been engine manufacturers were Pratt and Whitney predicted. Emigrants crossing the Atlantic and Wright. It will readily be recognised that a would not even have thought of flying and the few key names are missing, including Boeing, very limited airline services were restricted to Airbus, General Electric and Rolls-Royce, the very wealthy; it was common in newspaper giving some indication of the enormous changes offices to see photographs of the celebrities that have occurred. arriving by aircraft. When immigrants arrived in North. America they would immediately get 01.1 H.I.H. Saravanamuttoo Travel times between continents were carried 40 passengers over a 500 mile range measured in terms of days or weeks and there using two Pratt and Whitney R2800 14 cylinder was very little business or vacation travel as we radial engines. It should be noted that US know it today. Typical times by ship were piston engines were designated in terms of their London to Montreal 8-10 days, London to swept volume in cubic inches; 3350 cubic Colombo 18-21 days, and London to Sydney inches is equal to 204.4 litres. These engines 30-40 days. In the 1950s it was common to required 100/135 octane fuel, specially blended meet immigrants who had spent 20-30 years for aircraft applications. The US airline working in North America saving up for a industry used solely air-cooled radial engines, single trip to the old country. We shall see that being distrustful of the complications of liquid it was the aeroplane, and in particular the advent cooled in-line engines; the Rolls-Royce Merlin of the jet engine, that has resulted in a world liquid cooled engine was used in the Canadian where it is commonplace to cross the Atlantic or version of the DC-4, known as the North Star in Pacific several times a year and executives Canada and the Argonaut in Britain. There is routinely make weekly transcontinental trips. no question that the air-cooled radial was more Some recent examples of very long range successful. flights resulting from propulsion developments The piston engine reached its peak in the include the following: Lockheed Super Constellation, Boeing Stratocruiser and Douglas DC-7C. Wright Distance developed the R3350 TC18 for the DC-7C and Year Destination (nm) Time Engine L-1649 Super Constellation, with exhaust 1989 London-Sydney 9720 20 hrs. RB211- driven turbines which were connected to the 9 min. 524G crankshaft through quill shafts and fluid 1993 Auckland-Paris 10392 21 hrs CFM56-5C 46 min couplings to increase the power supplied by the 1996 Seattle-Kuala 10823 21 hrs Trent 800 pistons; this was known as the turbo compound Lumpur 24 min. (TC) engine and achieved a specific fuel consumption of 0.38 lb/BHPhr, the ultimate for The above, of course, is the engine man’s the piston engine. The Stratocruiser used the point of view and it should be noted that the Pratt and Whitney R4360, a 28 cylinder turbo engines were connected to 747-400, A340 and supercharged engine using 4 rows of 7 777 respectively. Each, in turn, represented the cylinders. Key data for these engines is given longest flight by a civil airliner; the Seattle- below. Kuala Lumpur flight flew eastbound over Europe, the distance across the Pacific would have been much lower. It should be emphasised that these were demonstration flights with minimal payloads, but it is useful to recognise that 10,000 nm is basically half way around the world and there is no merit in a longer range! 1950-1960 - The Transition from Pistons to Turbines At the beginning of the decade the dominant long haul aeroplane was the Lockheed Constellation, powered by Wright R3350 18 cylinder radial engines, with a take-off power of 2200 BHP and a weight of 2780 lb [1]. A very successful post war design, the Convair 240, Figure 1: Lockheed Constellation 01. 2 CIVIL PROPULSION; THE LAST 50 YEARS however, still had faith in the piston engine and BHP Weight Engine BHP (T/O) the DC-7 did not make its first flight until May (cruise) (lb) 1953; it is worth noting that the Comet 1 had Wright R3350 TC18 3400 1700 3645 already been in service for a year, and was Pratt & Whitney 3500 1750 3584 withdrawn from service after the DC-7 first R4360 flight. Key dates for first flights are given in According to Borger [1] both of these very Table 1. powerful piston engines had major reliability Table 1 problems; unscheduled removal rate of the FIRST FLIGHTS R4360 frequently exceeded 2 per 1000 hours and the inflight shutdown rate was “intolerable” Viscount R-R Dart July 1948 (too high to guess a number?). After numerous Comet DH Ghost July 1949 Britannia Bristol Proteus August 1952 modifications, engine operation was considered DC-7 Wright R3350 May 1953 to be barely tolerable. The R3350 was plagued 707 (KC-135) P&W JT3 July 1954 by service problems and Borger concluded that 747 P&W JT9D Feb 1969 the problems were soluble; the engineering Concorde RR Olympus 593 March 1969 spirit was willing but the financial backing was 767 P&W JT9D Sept. 1981 almost non existent. It is perhaps not a great It was clear, however, that the writing was surprise that Wright was the first of the big on the wall for the piston engine. Boeing flew a names to disappear from the engine business. prototype of the KC-135 tanker in July 1954, The DC-7C and the L-1649 were the only and one year later were authorised to produce a piston engined aircraft with a true westbound civil version which became the 707; this was the transatlantic non stop range. During the piston aeroplane that really launched the jet age. On era airports such as Gander and Shannon were October 13th 1955 Pan American placed orders necessary because of the limited ranges of for 20 707s and 25 DC-8s, the DC-8 being the piston aircraft, but these have not been required Douglas entry into the turbine era. The first for many years. flight of the DC-7C did not occur until two The limitations of the piston engine months after this landmark order. Lockheed focused attention on the prospects of the had a different view and announced the turbine, in the form of both turboprops and development of the Electra in 1955, a four turbojets. The jet engine was already playing a turboprop short-medium range airliner. dominant role in military aircraft and the In the twilight of the piston era the DC-7C Viscount (turboprop) had its first flight in July and L-1649 were operating on the Atlantic in 1948 while the Comet 1 had its first flight in 1957, with the Super Constellation providing July 1949.