T. H. Wintringham
Source: Labour Monthly, December 1930
Transcription: Phyll Smith
HTML Markup: Brian Reid
Public Domain: Marxists Internet Archive (2008). You may freely copy, distribute, display and perform this work; as well as make derivative and commercial works. Please credit “Marxists Internet Archive” as your source.
A CABINET Committee of the first Labour Government decided, in May, 1924, that two new airships should be built, each nearly twice as big as any previous vessel of this sort. A Cabinet Minister of the second Labour Government received the report, on October 5, 1929, that the second of these two ships, R101, was ready to fly. Exactly a year later this airship lay burnt out at Allonne, near Beauvais. Fifty-four men had been sent out in her to fly to India; forty-seven of these died at Allonne.
This disaster was not so great, in the money value of vessel and cargo, as most of the unnumbered disasters of the sea; nor were the deaths more numerous than those normally occurring in any fortnight’s operations of the British mine-fields. But it caught the imagination of the capitalist world because of the greatness of the hopes that were put to the test of fortune in this flight ; because of the scale of the gamble, and its dramatic quality ; and because the disaster seemed to almost all outside Britain, and to many in Britain, a clear sign of the decay that is corroding the imperial power of Britain, a clear omen of the disaster to which is doomed British imperial policy—now becoming equally a gamble in the dark against head winds.
And this airship disaster has interest for the revolutionary working class, quite apart from our indignation at lives thrown away; it shows with what criminal eagerness the Labour government presses forward the policy of British imperialism, “the linking of the Empire,” and also shows to what a pitch of disregard for risk the Labour Government has been driven, by its need for a demonstration of courage and Imperial achievement, its need for a success somewhere, anywhere, to relieve for a few days or weeks the dark record of increasing crisis.
The court of enquiry into the disaster has adjourned for three weeks at the time of writing. But so much revealing evidence has been given that it is difficult to choose which of the technical aspects can most usefully be dealt with in this article. To prove the callous rashness with which the Labour Government sent this vessel out on its last flight, we need only look closely at one of the many points in regard to which the airship was experimental, untested, and—judged by any normal engineering standard—unsafe.
The engines of R101 were of a type never before used in an airship. They ran on a fuel never before used in an airship. Their designers experienced constant trouble. Three experimental types were built in succession the second of these, the “Tornado Mark II,” was to give 650 h.p. for 3,100 lbs. weight dry; but it vibrated itself to pieces. How serious were the difficulties on this side may be seen from the fact that the third type, the “Tornado Mark III,” weighed 4,700 lbs. and gave only 585 h.p. The makers of the engines had to increase the weight per horse-power from 5 lbs. to 8 lbs—a big jump!
These heavier engines were never given a full-speed test, in the airship, without some accident happening. An engine failed during the only high-speed test attempted. Another failed in the last test flight before the trip to India. Another worked badly between 8 and 11p.m. on the trip itself.
The gas-bags were of a material never previously used in Britain they were fixed in the vessel by a novel method an inspector reported that they fouled sharp projections in the framework and “there are now many holes in them” (letter of F. McWade, read in Court of Inquiry on November 7, 1930). He reported to the Air Ministry that padding these projections was unsatisfactory; the Air Ministry wrote back that it was necessary to see the projections were properly padded (letter of Major Bishop, read same day).
The designer of the vessel reckoned that the gas-bags might be leaking at such a rate that the vessel would lose “4 to 5 tons lift in 12 hours” (Col. Richmond’s minute, read same day). But the only major alteration ever made in the matter of R101’s gas-bags was an alteration (made with a view to the trip to India) which increased the size of the bags, gave less clearance between them and the framework, and increased the number of “points of fouling” where holes might be made.
Defects almost as serious as these have been revealed in most of the important parts of this enormous and complicated piece of machinery. They were not remedied: remedies were tried (as for example, the padding of the gas-bags), but no one will ever know if they were effective to any extent.
Facts such as those we have noted about the engines and the gas-bags, are sufficient in themselves to convince most workers of the desperate risk of using such a machine for a flight to “limit range,” which could only be successful if every part functioned correctly. But it is not possible to make clear the full facts about the engines and the gas-bags without going into technical points such as the effect of torsional vibration on the engine crank shafts, or the “co-efficient of discharge” of gas through holes in the bags.
One main question, however, can be treated fully without going too far into technical formulae that is, the question of the stability of the airship, its ability to fly at a constant height above the ground, without sudden “nose-dives” which would bring it into danger.
No airship is completely stable. But after careful tests it is possible to say, of a vessel whose qualities in all positions of flight are known, that in recovering from “a bad angle” (a steep tilt upwards or downwards) the vessel will rise or fall 200 feet, or 600 feet or more, according to speed, gustiness of the wind, original angle of flight, &c.
No such data had ever been accumulated for R101; her test flights had almost all been with four engines out of five working, and the only approach to a full speed test was in “perfect weather” (Col. Richmond’s diary). If therefore she had a “critical angle” at a certain speed relative to a gusty wind—an angle certain to be followed by a long and steep dive—this was not known it could not be guarded against.
There are two natural factors of instability in any airship. These can be described as internal and external.
If a vessel for any reason dips her nose, fuel and ballast in all the tanks which are not completely full tends to run towards the nose, tipping her further down. The lifting gas, on the other hand, tends to act slightly further back, lifting her tail. That is what we have called the “internal” factor of instability.
The “external” factor is due to the pressure on the surface of the vessel of the wind in which it is flying. Instability due to this is very much increased if the vessel is flying “out of trim,” with its nose either up or down.
To counteract this instability an airship has fins at the tail, like the feathers on an arrow, and behind these fins movable rudders and elevators.
Even in fine weather at low speeds the vessel is always tilting slightly, and has to be held level and on a straight course by the use of these rudders and elevators.
The “external factor” of instability is only partly due to what are called (wrongly) “vertical currents” of air. “Vertical” currents do not exist, except in very rare atmospheric conditions; but currents of air do occur which flow at an angle relative to ground level, and these may seriously affect stability. The only possible way of guarding against the effects of these currents is to fly high enough to make certain that the vessel can be brought back to the level before it strikes the ground.
There are two points in this matter that have to be kept clearly in view. One is that R101 flew at a maximum of 1,500 feet above sea level. The second is that by the time R101 had reached Beauvais she must have been flying at an angle, with her nose down—unless the gas-bags were leaking very badly indeed, so badly that the ship ought at once to have been turned back.
The height at which R101 flew was reported as rather more than 1,000 feet over London, and 330 feet over Poix aerodrome, which is nearly 700 feet above sea level.
Major C. C. Turner stated in the Daily Telegraph for October 18 that the usual height for the first stage of a British airship’s voyage is 2,000 feet, “but for R101’s last voyage I believe a somewhat lower level was chosen—either 1,5000 feet or 1,000 feet.”
A low level of this order is chosen because hydrogen gas expands in the thinner air as a vessel goes up. R101’s gas bags, at the start of the voyage, would be not quite full; when she reached the predetermined height (called “pressure height”) of 1,500 feet or 1,000 feet, they would be quite full; if she went higher some of the gas would escape out of the valves.
There is certain to be a good deal of loss of gas later on, during the day when the sun warming the gas causes it to expand, and holes in the gas bags have developed. Therefore, gas is precious at the beginning of a flight. And for this reason a flight is begun at a low level, to keep as much gas in the bags as possible.
How low a level is safe? That depends on the known behaviour of the ship. R101 is said to have come down, in her last dive, at an angle of about 25 degrees. At that angle, and at her normal speed, she would hit the ground in less than two minutes from 1,500 feet. From 330 feet (the height reported over Poix) there would be only 25 seconds between her pitching and the crash.
By the time the vessel had reached Beauvais she must have burnt 3½ to 4 tons of fuel. If she had leaked anything like an equivalent of that amount of gas, the ship ought to have been turned back; she was certain to crash later when the escape of gas increased owing to the development of more holes. But it is not very likely that the leaks had yet developed to this degree.
If she had not leaked an equivalent amount of gas, it would have been necessary (in order to keep her down to the predetermined 1,500 feet level) to drive her at an angle nose down.
Major Turner writes, in the article quoted (written to prove that the airship was “not over-burdened”) that “by the time she reached Beauvais she had, doubtless, consumed about four tons of fuel. This would cause her to rise a further 800 feet or so, but the ascent could be prevented by driving the ship bag slightly head down by operating the elevator plane.”
That is almost certainly what was done. Increasingly the vessel must have been flown at an angle to the ground.
We have already seen that this angle is one of the important main factors in “external instability.’’
Now we can consider the second main factor—speed. From Cardington to Hastings, the ship covered her first 100 miles in three hours. From Poix aerodrome to the hillside at Allone she covered her last 25 miles in minutes. Her speed had fallen from 3 miles per hour to 20 miles per hour.
But that is speed relative to the ground. Relative to the air in which she was flying, R101 was going as fast in the later stages of the flight as earlier on: we have the evidence of tile engineers that the engines ran at cruising speed throughout, except between 8 p.m. and 11 p.m. during this period the aft engine was slowed down owing to oil trouble.
All that the slowing up of ground speed shows is that the head wind was increasing. The airship reported its air speed by wireless as being 62 mph.
An increasing wind generally means an increasingly gusty wind. If the vessel was flying at an air speed of 60 mph. and making a ground speed of 20 m.p.h., the average force of the head-wind must have been at least 35 m.p.h. (the other mph. being accounted for by errors of direction, which seem actually to have been almost negligible). Meteorological evidence also points to a wind of this average velocity.
Such a wind may occur in gusts varying in force between to 20 m.p.h. and 50 mph. This is particularly likely to occur in the lee of a range of hills, as at Beauvais.
If a lull (i.e., a period during which the wind is round about 20 m.p.h.) occurs and is prolonged, the airship will speed up, relative to the ground, to 40 m.p.h. ground speed. If she then meets a gust of 50 m.p.h. her air speed relative to this gust may be 90 m.p.h. for a moment, until she loses weigh. These are conditions which almost certainly occurred. What is their effect?
The vessel was increasingly having to fly at an angle—which the navigators knew to be safe in such weather as they had experienced, at such speeds as those reached in the tests (i.e., with four engines, except for one short period in perfect weather).
Had they ever met a gust which would increase their air speed to 90 m.p.h. or so, at such an angle? No.
It is possible that other factors may have added to the danger, or even been the final determining cause of the crash. But the main conclusion to be drawn from the enquiry evidence is that this vessel—reported on a trial flight to be “bumping, dipping, and plunging” (Captain Meager, at inquiry on November 10) when flying relatively slowly in calmer weather—came into a gust near Allone at an angle which, for a gust of that force, was beyond the “critical angle.”
One other point as to stability may be noted. R101 was originally 724 feet long and of 5,000,000 cubic feet capacity. For the flight to India she was increased to 777 feet in length and a capacity of 5,500,000 cubic feet.
No model tests were ever undertaken to see if the fins and rudders considered capable of controlling the 724 feet vessel could control effectively the enlarged vessel, 10 per cent, bigger.
The only possible conclusion, then, from the facts known as to the vessel’s stability is that it was a criminal risk to fly such a ship within 2,000 feet or more of the ground during “heavy weather.” It was particularly risky when the vessel was carrying 20 tons or more of fuel and passengers, because in such a case the available emergency ballast represents a smaller total proportion of the gross weight of the ship, and has a less rapid effect than it does when the vessel has less fuel aboard and less gas in the bags. It was even more risky to try to conserve gas by flying with the nose pitched down.
All these risks had to be taken if the flight to India was to be carried through.
That flight had to be carried through, while the Imperial Conference was sitting, for Imperial reasons. Lord Thomson, Secretary of State for Air, agreed to official minutes and signed memoranda in which he advised a slow, cautious and progressive testing of the airship. But in another minute he had written: “I must insist on the programme of the India flight being adhered to, as I have made my plans accordingly.”
It is obvious that the first of these, advising caution, was a formal document only. The second was an order that had to be obeyed. Squadron-Leader Booth, commander of R100 (the other Labour Government airship) said that the existence of the Imperial Conference “biassed the judgment” of the officers in charge. How much more likely to “bias their judgment” was the “I insist” of Lord Thomson, His Majesty’s Secretary of State for Air—and the man who boasted that the first telegram of congratulations he received after being made a Lord was one from Mussolini.
“I have made my plans.” But it was not as an individual that Thomson planned. It was the plan of the Labour Government. They knew that the Imperial Conference could not reach, yet, a dramatic and successful result. They wanted a great burst of popular enthusiasm—newspaper-created—to cover the ending of the Conference. The risks, the need for longer tests, did not matter.
The responsibility of these “Socialists” for this disaster is complete and inescapable.