The story of the R100 and R101 airships
The lure of new ideas
The building of R101 was a glamorous public project carried out with a fanfare of enthusiastic publicity. It was quickly announced that she would be ready in two years and would be able to fly to India in the spring of 1927. This was sheer rubbish.
R101 was, as originally conceived, 737 feet long and 131 feet wide, a little longer and a fraction narrower than R100. Her design was innovative. The Director of Design, Colonel Vincent Richmond, decided to make the frame not from Duralumin, as had been used for the Zeppelins and R100, but from stainless steel. Steel is much stronger than aluminium alloy but, as any bicycle owner will know, it’s impossible to make a steel structure as light as an aluminium one of the same strength. The frame was designed to be stiff enough to largely avoid the need for bracing cables, but this caused it to protrude into the interior of the hull, reducing the space available for gasbags. The designers were haunted by the memory of the collapse of R38, and whenever there was a choice between a lighter component and a more durable one would choose the second. All these factors added up to one thing: less lift.
The problem was made far worse by the choice of the Beardmore Tornado diesel engines. The combined weight of the five fitted, including their accessories ,was nearly 19 tons, offset by a saving of only 6 tons in the smaller amount of fuel they would use on the voyage to India. Even the supposed safety of using non-inflammable diesel fuel was lost because these massive engines needed small petrol motors to start them. Plans to replace the starter motors with oil engines were never realised.
Not only were these engines absurdly heavy, they would prove a source of unending trouble. They could never be run at their maximum speed and power, and failures of components were frequent. The original plan had been to use metal propellers with movable blades that could be angled backwards for reversing, but these disintegrated during testing and were abandoned in favour of simple wooden ones. The engines had no reversing gear, so it was decided that four would be used for forward flight and one kept purely for going backwards – almost four tons of dead weight for most of the time. You will remember that R100 had six engines which could deliver their full 650 hp, far beyond the faltering output of the Tornados, and two of which had mechanical reversing gear. R101 was dangerously underpowered.
A lot of money was wasted. There was a plan to recommission the old airship R36 and fly her to India to try out the feasibility of the route. After R36 had been restored, the plan was abandoned. A whole section of R101’s hull was built for stress tests and scrapped after testing. The Air Ministry bought tons of ferro-silicon, used in making the steel alloy for the frame, decided they had bought too much, sold it, found that in fact they needed it and bought it back for five times as much.
The design team kept changing things. As a result, the contract with the firm making the girders was broken and the firm had to be compensated. This caused further delay.
One economy was made – a false one. The design team wanted a mechanical calculating machine to ease their task. This would have cost £50. Their request was refused, so calculations continued to be made by hand, at much greater expense in wages.
The team’s enthusiasm for innovation attracted new and sometimes dubious designs. One of these was for the gas valves. As an airship rises, the air pressure outside it falls. The gasbags couldn’t adjust to this by swelling more and more like a rubber toy balloon, partly because the goldbeater’s skin they were made of was not strong enough, and partly because the gasbags would touch the frame and this would chafe holes in them. Both R100 and R101 were designed to have a ‘pressure height’ of 1000 ft. This was the height at which the gasbags would be fully expanded. To rise to their proposed cruising height of 1500 ft they would need to vent off gas through valves. It was also necessary to vent gas when descending to a mooring mast.
On previous airships the valves were simple large spring-loaded flaps at the bottom of the gasbags. The designers of R100 followed this well-tried design. They didn’t even make their own valves – they bought them from Zeppelin. Colonel Richmond and his assistant Squadron Leader F.M. Rope had what they thought was a better idea, and designed new valves which were fitted halfway up the gasbags. They were extremely sensitive to changes in pressure, and would vent gas if the airship rolled as little as 5° – which she often did even at her mooring mast.
Gasbags are attached to the hull of the airship with a harness of wires, which must keep them from chafing against the hull. Richmond and Rope designed novel harnesses of great complexity which were supposed to spread the load on the hull evenly if a leak caused one gasbag to deflate. This didn’t work at all well, and allowed the gasbags to chafe against the frame. Later, one bag was found to have 103 holes in it.
The usual way of covering the hull of an airship at this time was to attach cotton canvas and then paint it with cellulose dope, which waterproofs and strengthens it and also causes it to shrink, so that it clings tightly to the frame, increasing its rigidity. Richmond had a different idea, which he had invented for the fabric of balloons during the war. This was to pre-dope the fabric and, when it was draped on to the frame, to draw it tight with strings glued to the fabric with rubber solution. It’s difficult for a modern reader to grasp how primitive materials and adhesives were in the 1920s.
Like R100, R101 was built with only 16 main longitudinal girders. Richmond realised, rightly, that the enormous space between then would allow the covering to flap, so he added another 16 lighter longitudinal braces midway between the girders, which were also used to reef in the covering to tighten it. But in the event this seems not to have worked, as we shall see.
The calculations of R101’s designers showed that the huge rudder and elevators on the tail fins, each one 44 ft long, would be too heavy to move by hand, and would need power assistance. Accordingly, large servo motors were installed to move them. The calculations of R100’s designers showed that no power assistance would be necessary, and this was borne out in practice – though there was a moment of panic at Howden when they heard that R101 had servos, and did all their calculations again.
So construction proceeded with much revision, and many novel devices burdening the airship. In September 1929 the time came to fill her with hydrogen and discover the amount of lift she would provide. They discovered to their horror that this was not the 60 tons they had expected, but barely 35 tons – 27 of which would be taken up by a full load of fuel. The weight of the airship had grown from the projected 90 tons to 113 tons 12 cwt.
Not much could be done about this immediately. In the face of excited public expectation, they had to get her out of the shed and into the air. Winds were unfavourable for a while, but finally, on 12 October 1929, she was walked out and hung in the air, her fabric gleaming with fresh aluminium dope. Her number R101 was proudly painted on her side, and below it her British registration G-FAAW. Despite the delays she was actually launched two months ahead of R100, whose construction had been slow because of a lack of staff and tools, but had at least proceeded in a straight line.
Two days later R101 made her first flight, going around Bedford where huge crowds had come to view her. She was flying on only two engines, as the Tornados were giving trouble. Subsequent flights were made as far as Belfast, all in calm weather. On one trip she managed an average speed of 60 mph. While she was moored at her mast, she survived a gale with gusts up to 83 mph. Outwardly, all seemed well.
But the fact remained that with a full load of fuel she could barely carry ten tons of crew, passengers, baggage and stores. There was a desperate attempt to lighten her by removing as much unnecessary weight as possible, including the servo motors in the fins, and by letting out the wire harness of the gasbags as far as possible to allow more hydrogen to be put in. These measures gained six tons of lift, still not nearly enough, and increased the problem of gasbags rubbing against the frame and being holed.
Desperate measures were called for. They decided to add 40 feet to the middle of the airship, enough to put in an extra gasbag.
Another problem appeared in the summer of 1930. The canvas covering, doped before being put on by Richmond’s patented process, started tearing. They found that it had rotted. Also, the rubber solution used to glue the tightening cords to the cords to the fabric had reacted with the cellulose dope and caused further damage to the fabric. The whole covering would have to be removed and every trace of it carefully scraped off before re-covering the frame with canvas applied in the conventional way.
The annual RAF display at Hendon was coming up, and R101 would have to perform a flypast (at this time R100 was about to fly to Canada and couldn’t take part). They patched up the holes and set off on 27 June. The airship behaved disquietingly poorly, pitching so much that one of the cables supporting the gasbags snapped. The outer fabric flapped but couldn’t be tightened because of its frail condition. Holes in the gasbags, and the novel and oversensitive gas valves, caused considerable loss of gas. Large amounts of ballast had to be shed. They barely made it back to Cardington.
Then R101 was put back in her shed to be lengthened, which was not such an arduous task as you might suppose. She was kept inflated, held in place by ropes with weights, and simply unbolted in the middle. The halves were pulled apart and the new section bolted in.
At the same time, all the rotten covering was stripped off and replaced. The insane plan of using only four of the five engines for forward propulsion was abandoned. They modified two of the engines so that they could be stopped and restarted turning backwards, which was done by altering the camshafts – this must have reduced their performance further. The engines were still incapable of running at full speed and R101 remained gravely underpowered, a problem made worse by her extra length.
She emerged from the hangar on 1 October, now 777 feet long. It’s hard to imagine what she looked like in the air, and contemporary photographs and film don’t fully capture it. But consider this: the enormous tower at Canary Wharf in east London is only 771 feet tall. Imagine this turned sideways and floating in the air.
The hubris of Lord Thomson
On 5 June the previous year Ramsay MacDonald had returned as Prime Minister of a Labour-Liberal coalition, and Lord Thomson was again Air Minister. He was avid to see R101, his giant baby, give a triumphant demonstration of the wonder of public enterprise. It had to be done quickly: R100 had flown successfully to Canada, and it was simply impossible to let his glorious venture be upstaged by a cheap capitalist exploit. Also, Thomson had political engagements and had to be back in London by 20 October at the latest.
At Cardington, those who knew more about the airship’s weaknesses hid their foreboding.
Under pressure from Thomson, the final tests were rushed, and there was just one 24-hour test flight. It was impossible to do a speed test, as the engines were playing up again. R101 had been hastily given an Official Permit to Fly over the telephone. Her full Certificate of Airworthiness was issued on 2 October, before the full report on the recent changes had been completed.
The departure for India was finally scheduled for Saturday 4 October 1930. There was no time for any more testing: the interior had to be spruced up for the distinguished passenger and his retinue.
As the passengers boarded, there was a final blow to R100’s feeble lifting capacity. The baggage allowance for each passenger was 100 lb. But Thomson arrived with so much luggage that it took two journeys of the lift in the mooring mast, capacity twelve people, to bring it up. It was not weighed but the lift attendant, Herbert Mann, reckoned it at 1800 lb.
The weather was foul, with wind and rain, and forecast to get worse. They had never been out in conditions like this – but R100 had survived a storm in Canada, and they were obliged to equal that performance. Nothing could stop them now. Piloted by Flight-Lieutenant H. Carmichael Irwin, R101 left at 6 pm, as the sun was setting invisibly behind the thick clouds.
She passed over the Isle of Dogs, rolling heavily and all the while losing gas from her ill-designed valves. East Enders who had turned out to watch her pass could see little but her navigation lights in the murk, and hear a faint roar of engines. Yet again, one of the engines had to be stopped, this time because of a faulty oil pressure gauge. It was restarted, but another engine was running rough, backfiring with showers of sparks from the open exhausts. As she crossed the coast at Hastings, watchers were shocked to see how slowly she was moving. She had lost altitude, and one observer estimated her height at only 500 feet above the cliffs, less than her length. To stay on course, she was travelling at a large angle to the wind.
Over the Channel, passengers and crew alike were alarmed by the closeness of the waves. Using the elevators and the lift given by her passage through the air in a nose-up attitude, she clawed her way up as she neared the French coast. She sent a wireless message in Morse: To Cardington from R101 2400 GMT. 15 miles SW of Abbeville. Average speed 33 knots. Wind 243 degrees 35 miles per hour. Altimeter height 1500 feet … Weather intermittent rain. Cloud nimbus at 500 feet … All essential services are functioning satisfactorily ….
At 1.45 her wireless operator took cross bearings from local transmitters, and signalled that they were near Beauvais. This was confirmed by a reply from Le Bourget aerodrome. At 2.07 and again at 2.13, Le Bourget asked for further information, but received no reply. Then news came in from observers on the ground, and the signal went out: G-FAAW a pris feu.
The final minutes
R101 had struck a ridge at Allonne, just southwest of Beauvais, and caught fire immediately. Forty-six people were killed on the spot; two more died in hospital. There were just six survivors: H.J. Leech, foreman engineer; A.V. Bell, J.H. Binks, A.J. Cook and V. Savory, all engineers; and A. Disley, wireless operator. With a certain rough justice those who who must bear the greatest part of the blame for the disaster – Lord Thomson, and Richmond and Rope – all perished. But so did Major Scott, who had piloted R100 on her successful flight to Canada.
The survivors were in various parts of the airship away from the bridge. Leech, off watch, was dozing in a chair in the metal-walled smoking room. So was Disley, in the chart room. The engineers were in various engine pods, whose position outside the hull helped to save their lives.
The commander of the airship, Flying Officer Maurice Steff, who had taken over from Irwin a few minutes before, was among the dead, so there can never be a full story of what happened in those last minutes.
The nearest eyewitness to the crash was Eugène Rabouille, who had gone out in the storm to set snares for rabbits. He recalled, ‘Suddenly there was a violent squall. The airship dipped by the nose several times, and its fore part crashed into the northwest edge of the Bois des Coutumes. There was at once a tremendous explosion, which knocked me down. Soon flames rose into the sky to a great height – perhaps a hundred metres. Everything was enveloped by them. I saw human figures running about like madmen in the wreck. Then I lost my head and ran away into the wood.’
At the enquiry it was thought that the cause of the fatal pitching was that the airship’s covering had torn open at the nose, and the inrush of wind had ruptured the bow gasbag.
A survivor related that when the airship began to pitch, a rigger, S. Church, was sent forward to release the emergency ballast bags in the nose, but it was too late. Shortly before she struck the ground, an order was sent to the engine pods to reduce speed. This was a fatal decision. R101 had been held up only by lift generated by her forward speed. When she slowed she sank irretrievably.
Several suggestions have been made about what started the fire so quickly. It may have been sparks from the exhaust of the malfunctioning engine. When the drifting hydrogen caught fire, it burned so fiercely that supposedly non-flammable diesel oil leaking from the smashed fuel tanks also caught, turning the ground into a field of fire.
The bodies of the dead were placed in hastily collected coffins in the black-draped town hall before being sent back to England. The funeral was on 12 October 1930, exactly a year after R101 had first been walked out of her shed.
R100 hung, serviceable but unusable, in the shed at Cardington. There was talk of continuing tests and even building a successor, but understandably it came to nothing. After a year she was hacked up with axes and her delicate lattices steamrollered flat. The scrap metal was sold for less than £600.
What might have happened?
Suppose that R101 had survived her first night. Probably she would have faltered on for a few more miles and, in the absence of a mooring mast, been ditched somewhere in France and abandoned by crew and passengers. The contest would have been over, with R100 a clear winner.
And further suppose (and it’s a big supposition) that the government had played straight, and had gone on to build R102 and subsequent airships as improved versions of R100. As long as Vickers could keep away from the idiotic decisions of committees, it would have been possible to rectify the design faults of R100. The overlarge fabric panels could have been stiffened in a better way than on R101. Building the airships in the cosy hangar at Cardington would save the need to apply tons of varnish to the duralumin frame. There were already proposals to lengthen R100 to provide more useful lift.
It would even have been possible to use diesel engines – and not the monstrous Beardmore Tornados. In 1932 a diesel version of the R100’s own engine, the Rolls-Royce Condor, was tested. Extra strengthening to withstand the higher stresses of a diesel increased its weight by only 124 lb, and its more frugal consumption would have more than offset that, since less fuel would be carried. Power was down from 650 bhp to 480, but that would have increased with development, and R100 was overpowered anyway.
So, by the early 1930s, there would have been a British airship service to Canada and India and beyond. Until when? There was bound to be a hydrogen-fuelled disaster in the future. But in the event it happened to the Hindenburg, at Lakehurst, New Jersey, in 1937.
Perhaps we were lucky that we had to stick to ordinary aircraft. After some early and inconclusive attempts, in 1937 Imperial Airways set up a service using Short Empire flying boats to hop along seas and inland lakes, first reaching Cape Town and then, in 1938, going all the way through India to Australia in ten days. The service was not without accidents, but by the time World War II brought it to a halt it had shown that intercontinental passenger air travel was possible, and laid the foundations for today’s long-distance airline services.
© Tachybaptus 2018