R100

Infobox Aircraft
name="R100"


caption=The R100 on a mooring mast in Canada
type=Airliner
national origin=United Kingdom
manufacturer=Vickers
designer=
first flight=16 December avyear|1929
introduced=
retired=
status=
primary user=
more users=
produced=
number built=1
variants with their own articles=

HM Airship "R100" was a privately designed and built rigid airship built 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 offered by the German airships. Soon after 1920, Vickers' experts had calculated that the fare on an airship journey might be £45 (around US$215 at the time), [Ward, Ian, ed. "The World of Automobiles" (London: Orbis, 1974), Volume 13, p.1562.] 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. [Norway later found fame as a novelist.]

Design and construction

The "R100" was constructed at the former RNAS Air Station near Howden in Yorkshire, a remote location convert|3|mi|abbr=on from Howden and convert|25|mi|abbr=on 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.cite book | last = Ventry | first = Arthur Frederick Daubeney Eveleigh-de Moleyns | authorlink = | coauthors = Eugène M. Kolesnik | title = Jane's Pocket Book of Airships | publisher = Collier Books | date = 1977 | location = | pages = p. 137 | url = | doi = | id = | isbn = ] 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 convert|5000000|cuft|abbr=on 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 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 before it was required and it was decided to fit Diesel engines of the same type that were being developed by the Air Ministry for 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 even though these were considered more of a fire risk, fitted in three gondolas. [cite book | last = Hartcup | first = Guy | authorlink = | coauthors = | title = The Achievement of the Airship: A History of the Development of Rigid, Semi-rigid, and Non-rigid Airships | publisher = David & Charles | date = 1974 | location = | pages = p. 189 | url = | doi = | id = | isbn = ] 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 as the Diesel engines had been developed especially for the "R101" and had to be used.

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 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, 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 convert|50|mph|abbr=on 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 convert|10|mph|abbr=on than the "R101". In fact, during a test on 16 January 1930 the "R100" achieved a speed of convert|81|mph|abbr=on, making her the fastest airship in the world. [cite book | last = Taylor | first = John William Ransom | authorlink = | coauthors = Michael John Haddrick Taylor, David Mondey | title = Air Facts & Feats | publisher = Sterling Pub. Co. | date = 1978 | location = | pages = p. 23 | url = | doi = | id = | isbn = ]

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 convert|15|ft|abbr=on.

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 main Canadian mooring station at the airport in Saint-Hubert, Quebec in 78 hours hacing covered the great circle route of convert|3300|mi|abbr=on at an average speed of convert|42|mph|abbr=on. 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 "" 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 "", 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, "R-100" represented the best that conventional airship technology in Britain had to offer at the time, whereas "R-101" 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.

When "R101" crashed and burned, the Air Ministry ordered all "R100" flights stopped. 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.

pecifications

aerospecs
ref=
met or eng?= eng

crew=37
capacity=100
length m=219
length ft=719
length in=9.5
span m=
span ft=
span in=
swept m=
swept ft=
swept in=
rot number=
rot dia m=
rot dia ft=
rot dia in=
dia m=41
dia ft=133
dia in=4
width m=
width ft=
width in=
height m=
height ft=
height in=
wing area sqm=
wing area sqft=
swept area sqm=
swept area sqft=
rot area sqm=
rot area sqft=
volume m3= 146,000
volume ft3= 5,156,000
aspect ratio=
empty weight kg= 107,215
empty weight lb= 236,365
gross weight kg=
gross weight lb=
lift kg= 159,400
lift lb= 350,610

eng1 number=6
eng1 type=Rolls Royce Condor IIIB 12 cylinder
eng1 kw=
eng1 hp= 650
eng2 number=
eng2 type=
eng2 kw=
eng2 hp=

max speed kmh= 131
max speed mph= 81.5
max speed mach=
cruise speed kmh=
cruise speed mph=
range km=6,590
range miles=4,095
endurance h=64
endurance min=
ceiling m=
ceiling ft=
glide ratio=
climb rate ms=
climb rate ftmin=
sink rate ms=
sink rate ftmin=

armament1=
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Notes

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

* [http://www.aviation.technomuses.ca/pdf/r100.pdf The R100 in Canada (pdf)]
* [http://www.aht.ndirect.co.uk/airships/r100/ Airship heritage Trust R100]