| R100 | |
|---|---|
 |
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| The R100 on a mooring mast in Canada | |
| Role | Airliner |
| National origin | United Kingdom |
| Manufacturer | Vickers |
| First flight | 16 December 1929 |
| Number built | 1 |
HM Airship R100 was a privately designed and built rigid airship made as part of a two-ship competition to develop new techniques for a projected larger airship for British military use. The other airship, R101, was built by the UK Air Ministry.
One goal was to eventually offer a regular and comfortable trans-Atlantic service, akin to that eventually offered by the German Graf Zeppelin. Soon after 1920, Vickers' experts had calculated that the fare on an airship journey might be £45 (around US$215 at the time),[1] compared to a contemporary airliner fare of £115 (about $550), and the non-stop range of an airship would be far superior, making the journey quite competitive.
R100 was built by the Airship Guarantee Company, a company created solely for the purpose, as a subsidiary of the armaments firm, Vickers-Armstrongs. The managing director was Cdr Dennis Burney, and the design team was led by one of the most prominent aircraft engineers of the time, Barnes Wallis. The design team also included, as senior stress engineer, Nevil Shute Norway.[2]
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Design and construction
The R100 was constructed at the former RNAS Air Station Howden in Yorkshire, a remote location 3 mi (4.8 km) from Howden and 25 mi (40 km) from Hull. Design work began in 1925 while at the same time the somewhat rundown site was put in order and readied for construction to begin, including installation of a hydrogen-generating plant.
The Airship Guarantee Company faced substantial difficulties; the contract for the R100's construction had been a fixed price one and it was obvious from very early on that the project would incur a loss, and so economies were made; only a dozen machines in use in the construction of the airship. There were also difficulties in finding skilled workers due to the remoteness of the location, and a large proportion of the workers were local people trained to rivet and other mass production duties. Conditions in the unheated airship shed were also poor, with ice forming on the girders in winter and condensation causing corrosion of the airship's Duralumin so that the girders had to be varnished. This was done so well that when the ship was eventually broken up the structure was in perfect condition.
For three years the actual assembly work was close behind the designers, and the progress of the design work was the determining factor. Early in the design process it was realized that the huge airship could be steered by hand without needing servo assistance. When the designers learned that the R101 had been fitted with servo motors at a substantial cost in weight and money they thought that they had made a mistake and rechecked their calculations. They ended up by concluding that they had been correct, and in practice it was discovered that the finished airship could be steered by a single helmsman.
Construction
In both the R100 and R101 it had been decided to use relatively few longitudinal girders compared to previous ships so that more accurate stress calculations could be calculated; even so, the calculations for the transverse frames required hand computation that took two or three months to produce a solution. This decision had been taken following the catastrophic breakup of R38 in 1921. Fewer longitudinal girders, however, meant that there were larger unsupported panels of the fabric outer cover and in both airships the outer cover proved a weak point. Flight trials were to prove that the R100's cover was barely adequate.
Barnes Wallis effectively created the frame of the airship from only 11 standardized components fitted into a non-rectilinear framework. The girders of the R100 were formed of three helically-rolled and riveted Duralumin tubes, while the transverse frames (polygons made up of girders) were joined together by longitudinal girders.[3] His work on R100 later led to his innovative geodesic airframe fuselage design of the Wellesley, Wellington, and Windsor bombers. A further innovation he introduced was to colour code all the airship's wiring (a technique invented by Wallis and used for the first time on R80).
R100 was built suspended from the roof of its airship shed. The individual transverse frames were assembled horizontally then lifted up and slung to roof-mounted trackways before being slid into position and attached to the next frame using longitudinal members. The ship remained suspended until she was finally inflated with hydrogen.
By summer 1929 the ship approached completion and her gasbags were inflated. Her volume was a little over 5,000,000 cu ft (140,000 m3) giving a gross lift of about 156 tons. Her tare (empty) weight was around 102 tons, leaving 54 tons for fuel, oil, ballast, crew, and passengers. Following inflation of the gasbags, her outer covering of linen fabric painted with aluminum aircraft dope[3] was put in place, and she was completed in November 1929.
Propulsion
It had originally been intended to design special engines for R100 which would be fuelled by hydrogen and kerosene but after a year's work it was realized that the engine would not be developed in time and it was decided to fit Beardmore Tornado diesel engines that were being developed for the Air Ministry for installation in the R101. However, the diesel engines were judged unsuitable due to their weight and other reasons it was decided to use six Rolls-Royce Condor aircraft engines running on petrol and housed in three gondolas even though petrol was considered a fire risk.[4] A few months before the R101's first flight, her designer also urged the fitting of petrol engines due to the excessive weight of the Diesel engines, but this was refused by the Air Ministry; these Diesel engines had been developed especially from locomotive engines for the R101 and had to be used.[5]
The R100's designers had arranged for two of the airship's six engines to be fitted with reversing capability to allow her to slow down as she approached a mooring mast, and were amazed to learn that (because of the failure of the variable-pitch propellers) the R101 had been fitted with four engines with no reversing capability and a fifth, rear-facing engine which would only be used at the start and end of a flight,[5] at a cost of 3 tons weight including its gondola.
First flight
R100 made her maiden flight in the morning of 16 December 1929. After departing Howden she flew slowly to York then set course for the Government airship establishment at Cardington, Bedfordshire, cruising at around 50 mph (80 km/h) on four engines, and reached Cardington in two hours flight time. At the huge hangars at Cardington (some of which survive), two teams, the other led by the Air Ministry, competed to establish which was the better design in part via long demonstration flights.
The following day speed trials were performed. The officials at Cardington refused to believe that R100 could be at least 10 mph (16 km/h) faster than the R101. In fact, during a test on 16 January 1930 the R100 achieved a speed of 81 mph (130 km/h), making her the fastest airship in the world.[6]
Trans-Atlantic Voyage to Canada
The R100's contract originally required for a final acceptance trial of 48 hours' duration and a demonstration flight to India. This was later changed to a demonstration flight to Canada when the decision was taken to equip the airship with petrol engines, as it was thought that a flight to the tropics with petrol aboard would be too hazardous, and it was decided that the R101 would make the flight to India since she had Diesel engines.
Following a final acceptance trial of 54 hours the R100 was formally handed over to the Air Ministry, and a number of modifications were made in preparation for her transatlantic flight. During her last flight the tail fairing had collapsed due to aerodynamic pressures and her pointed tail was cut off and modified to a more rounded form, shortening her length by 15 ft (4.6 m).
Following R101's unsatisfactory trials in June 1930, the Cardington engineers tentatively suggested that the long flights to Canada and India might be postponed to 1931, saying that neither of the two airships were fit to make a lengthy flight at that stage. The R100 team responded that their airship was perfectly capable of flying to Canada, and that Canadian flight was a part of their contract and it was necessary for them to make it.
R100 departed for Canada on 29 July 1930, reaching the Canadian mooring mast at the airport in Saint-Hubert, Quebec in 78 hours having covered the great circle route of 3,300 mi (5,300 km) at an average speed of 42 mph (68 km/h). The airship stayed at Montreal for 12 days and over 100,000 people visited the airship each day she was there, and a song was composed by La Bolduc to commemorate, or rather to make fun of, the people's fascination with R100. She also made a 24 hour passenger flight to Ottawa, Toronto, and Niagara Falls while in Canada.
The airship departed on her return flight on 13 August, reaching Cardington after a 57½ hour flight.
Nevil Shute has suggested in his Slide Rule: Autobiography of an Engineer that the success of the R100's Canadian flight indirectly led to the R101 disaster; before the transatlantic flight, the Cardington team could suggest that neither airship was ready for a long flight, but when the R100 returned unscathed they had to either make the flight to India or admit defeat, which would have meant discredit and the loss of their jobs.
The end of the British airships
The tale of the design of R100 and its claimed superiority to R101 is told in Shute's Slide Rule: Autobiography of an Engineer, first published in 1954. In reality, the ship had several flaws which would have been expensive to repair, one being the need to reinforce the outer covering which was damaged by flapping caused by the design's widely spaced frames. However, R100 represented the best that conventional airship technology in Britain had to offer at the time, whereas R101 suffered in comparison because of her many groundbreaking, but ultimately problematic, innovations. It should be noted both were inferior to Graf Zeppelin in lifting efficiency.
After R101 crashed and burned in France, en route to India on 5 October 1930, the Air Ministry ordered the R100 grounded. She sat in her hanger for a year whilst three options were considered: a complete refit of R100 and continuation of tests for the eventual construction of R102; static testing of R100 and retention of about 300 staff to keep the programme 'ticking over'; or retention of staff and the scrapping of the airship. In November 1931, it was decided to sell R100 for scrap and the entire framework of the ship was flattened by machinery and sold for less than £600.
Specifications
General characteristics
- Crew: 37
- Capacity: 100
- Length: 719 ft 9.5 in (219 m)
- Diameter: 133 ft 4 in (41 m)
- Volume: 5,156,000 ft³ (146,000 m³)
- Empty weight: 236,365 lb (107,215 kg)
- Useful lift: 350,610 lb (159,400 kg)
- Powerplant: 6 × Rolls Royce Condor IIIB 12 cylinder, 650 hp (485 kW) each
Performance
- Maximum speed: 81.5 mph (131 km/h)
- Range: 4,095 miles (6,590 km)
- Endurance: 64 hours
See also
Comparable aircraft R101
Notes
- ^ Ward, Ian, ed. The World of Automobiles (London: Orbis, 1974), Volume 13, p.1562.
- ^ Norway later found fame as a novelist.
- ^ a b Ventry, Arthur Frederick Daubeney Eveleigh-de Moleyns; Eugène M. Kolesnik (1977). Jane's Pocket Book of Airships. Collier Books. p. 137.
- ^ Hartcup, Guy (1974). The Achievement of the Airship: A History of the Development of Rigid, Semi-rigid, and Non-rigid Airships. David & Charles. p. 189.
- ^ a b Gilbert, James (1975). The World's Worst Aircraft (3 ed.). Walton-on-Thames, England: Michael Joseph. pp. 83–84. ISBN 9780718112691.
- ^ Taylor, John William Ransom; Michael John Haddrick Taylor, David Mondey (1978). Air Facts & Feats. Sterling Pub. Co.. p. 23.
References
- Lord Ventry and Eugene Kolesnik, Airship saga: The history of airships seen through the eyes of the men who designed, built, and flew them , 1982, ISBN 0-7137-1001-2
- Manfred Griehl and Joachim Dressel, Zeppelin! The German Airship Story, 1990 ISBN 1-85409-045-3
- Ces Mowthorpe, Battlebags: British Airships of the First World War, 1995 ISBN 0-905778-13-8
- Lord Ventry and Eugene Kolesnik, Jane's Pocket Book 7 - Airship Development, 1976 ISBN 0-356-04656-7
- J.E. Morpurgo, Barnes Wallis - A Biography, Longman , 1972 ISBN 0-582-10360-6
- Nevil Shute, Slide Rule: Autobiography of an Engineer, William Heinemann, London 1954 ISBN 1-84232-291-5
External links
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