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The Airship, History and Handling, 18 Oct 2002 Messrs Brian Hussey and Don Williams spoke to us on Airships. They introduced us to the Airship Heritage Trust (based at Cardington) and the Airship Association. We were each given a copy of Engineering Technology, May 2001 in which Don Williams had an article on Airship Control by Remote Sensing. A Brief History - Brian Hussey The history of airships gives a good understanding of what they are, and of their associated problems. The first thoughts were in 1670 in Italy, when a gondola supported by four evacuated copper spheres about a metre in diameter was proposed – it would not have worked. The first people to fly were the Montgolfiers in their hot air balloon in 1783, heated by a bonfire on the ground - though they believed it was smoke that gave buoyancy, and used rather noisome fuel to produce it - its range was limited. Only eighteen months later the Channel was crossed, from Dover to Calais – troubles with lift meant that the crew had to throw out every portable thing, including their outer clothing. The first successful airship flew in 1898, designed by Santos Dumont who had designed a 3½ HP petrol engine for the purpose. He used one for personal transport round Paris… Airships typically fly at between 1000 and 2000 ft, lift being reduced at higher altitudes. Lift is provided by a lighter-than-air gas: hydrogen being lightest but flammable – particularly if contaminated by air leakage; the non-inflammable helium, though more expensive (10% of the cost of a new airship), is preferable and can be recycled. Germany, the most successful airship nation, generally used hydrogen – they were denied supplies by the USA in the late 1930s. The most successful was the Graf Zeppelin (1928-37) which travelled over a million miles without mishap to passengers or crew, although it could return with 2 - 3” lightning strike holes in the outer fabric and burn marks on the frame. (Gas bag holes could be patched in flight – there was usually plenty of time.) Blimps Non-rigid airships, inflated with hydrogen, were the first to be developed. Some early British ones were used for advertising – “Give Him Bovril” featured on one with “Give Her Bovril” on the other side – another read “Votes for Women”. The Royal Naval Air Service used blimps during the first world war for reconnaissance purposes. Flying one was said to be like waltzing with a jellyfish. With thrust from the propeller, control is by the fins and rudder, and trim adjustment by inflating the ballonets with air. BLIMP, length 90 ft Catenary LOAD CURTAIN Vertical Nose TOP FIN BATTENS Horizontal FIN and Control Surface Maximum Vertical Inflation LOWER FIN (with Air) and RUDDER Fore Aft BALLONET BALLONET Rigid Airships Count von Zeppelin was 62 when he started to design and make rigid airships at the turn of 20th century at Friedrichshafen by Lake Constance. The location is flat, with no mountains nearby. Germany used many Zeppelins in the first world war – for bombing – and, the Admiralty noticed, for observation at the battle of Jutland. At one time in 1916 there were 18 Zeppelins in the air – they came via the Happisburgh lightship, who informed the British authorities. After the war Zeppelins became available to the allies, most of whom used them as a basis for further work. In England R34 was built, and successfully flew to America and back. R38, modelled on a high altitude Zeppelin, probably without realising the implications, crashed during trials; this was designed to cope with low lift at high altitude and had a very light frame - it was not strong enough for more than gentle operation at low level. The British contribution to airship travel was the mooring mast, with a lift up the centre. The airship’s stern was moored to a heavy roller with its axis facing the mast, permitting some movement. R100 and R101 were built in 1929, for passenger travel to the Empire. The R100, with a duralumin lattice frame and gas bags sealed with a million goldbeaters skins (from the cattle trade in Chicago) was successful and flew to Quebec and back. But the R101, with a steel frame, and lengthened from its original design, crashed on its maiden flight to India when caught in a storm at Beauvais in France. This spelt the end of British airship travel. Germany continued to make Zeppelins, and after the Graf Zeppelin, made the Hindenburg in 1936. This was designed with cabins for 50, with a lounge and separate smoking room. There was elegant lightweight furniture and even an aluminium framed piano in the lounge. It plied the North Atlantic, until its second year when it burst into flames on being moored to the mast in New York – it is thought that leaking hydrogen was ignited by static electricity. That brought the end of passenger travel in rigid airships. The Future Airships do have their merits and design continues. Nowadays there are about 30 blimps in the world, inflated with helium; used for advertising, often fitted with internal lighting for extra effect at night. They also make good camera platforms, and can carry small numbers of passengers on sightseeing trips. Very high altitude airships are proposed for telecommunications or surveillance. High lift airships are being designed to avoid the need for roads when taking heavy plant to inaccessible sites: a 160 ton European Cargo Lifter, not necessarily an airship though currently it is, 853 ft long, needing 70m to complete development; in the USA ATG in Minesota are designing a twin hull SkyCat. The future of such airships is uncertain. Airship Handling - Don Williams Don Williams said he was an enthusiast but also sceptical. He spoke on three particular aspects: Position, Lift, and getting airships in and out of Hangars. Position Problems are mostly due to a lack of control, particularly near the ground. The GPS can say where you are, but getting an airship there and keeping it there is difficult. Despite now having engines with vector thrust, response is very slow - by the time a pilot has realised movement is happening it can be too late for corrective action. He suggested a means of detecting the first signs of airship movement by using half a dozen remote pilotless vehicles (RPVs), similar to drones already used for military purposes, orbiting the airship under its computer surveillance. Lift Blimps not only need gas for lift, but for it to be sufficiently pressurised to keep the shape - which reduces efficiency. The amount of lift required can vary not only with the load, but if rain adds weight, or as fuel is burnt. Fuel weight loss can be counteracted by letting off hydrogen – many early airship accidents are thought to be due to doing this in electrically stormy conditions (the success of the Graf Zeppelin was probably due to its use of a lightweight fuel giving it less need to let off hydrogen). One does not want to let off the relatively expensive helium; fuel weight can be maintained by condensing water from the exhaust, but there is then the weight of the condenser. Ballonets can be used, though in a rigid airship they would need to be stronger – modern plastics may be suitable. Lift can also be gained dynamically by raising the bow, and using forward motion as on an aeroplane. Hangar Entry/Exit Handling an airship on the ground can be fraught - a ground crew of 400 was laid on for the Hindenburg. Collision with the hangar would result in damage to an airship – there were frequent wreckages. The Zeppelin company made a floating hangar on Lake Constance and faced it into the wind when moving an airship in or out. However, even quite light gusts could still catch the airship, and move it horizontally or vertically – movements were usually done at 4am when winds were minimal. Mr Williams suggestion for this was to acquire outdated (cheap) turbine engines, and use a set of them to form an air funnel. Intermediate turbine/fans would probably be needed to give appropriate air speeds. Vote of Thanks The audience’s appetite being whetted, many questions followed [answers are incorporated in the above résumé ]. Mr Flemming thanked Brian Hussey and Don Williams for a fascinating talk. We were then invited to view various illustrations they had put out at the back of the room. And, if we wished, to purchase for £2.95 a book by Don Williams on a quite different subject, The Great No 1 Factory at Kingston, Surrey - where Sopwith aeroplanes were built in the first World War, then Trojan vehicles, and finally Hawker aeroplanes. The Society made a suitable donation to the Airship Heritage Trust. R J Buchanan The Hindenburg Disaster, 20 Dec 2002 This year we have had a talk on Airships, and another on Stress and Strain. During the Airship talk we heard of the R38. A spoil of the first world war was a high altitude Zeppelin designed with a very light frame to cope with low lift at high altitude - it was not strong enough for more than gentle operation at low level. The British used it as the basis for the R38, probably without realising the implications – it broke its frame and crashed during trials. Both topics came together a month ago when TV Channel 5 had a programme on the Hindenburg disaster in May 1937. Present day investigation techniques were applied to see what might have happened. Travelling the Hindenburg was said to be like magic - in luxury, floating silently in the air.

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