The Story of the R100 and the R101 III: The Airing of Grievances

R 100's control car.

While the story of how the Imperial Airship Scheme got to the end of 1929 took lots of words, summarizing our story is very simple. The British wanted to build a fleet of passenger airships, to serve the British Empire. Due to political shenanigans, the development of these airships was turned into a competition between the government backed Royal Airship Works (RAW), and private industry in the form of Vickers.  Each set out to build an airship, and whoever built the best airship would win the contract for the rest of the airship fleet. The RAW airship was the R101, and it was very ambitious, looking to pioneer new technology whenever possible; in contrast, the R100 was built on a very cost conscious budget, and used existing technology whenever possible. By the end of 1929, both airships had started flight testing, with the R101 having racked up more than 70 hours. The results of R101's flight testing were disquieting, to say the least: the government had spent a lot of money building a white elephant. No attempt had been made to hedge the risk of developing new technology in a project already very ambitious, and the result was that the R101 was riddled with engineering problems. Even more embarrassingly for the government - mistakes might have been made in the basic engineering, as R101 as completed had no payload capability. R100, in contrast, met her production contract and thus far had shown no problems - at least as compared to R101.

We rejoin the action at New Years Day, 1930. R100 retakes the mooring mast, as the R100 staff returns from Christmas vacation.

The Feats of Strength

R100's engineering staff was eager to get cracking once they returned, and R100's first flight managed to nail the narrative symbolism. While the R101 remained in its shed, suffused by the gloom of the British winter, the R100 flew above the clouds in sunshine. After breakfast (having a dining room onboard your test aircraft simplifies some logistics marvelously) the R100 performed the top speed test again for on-board Air Ministry officials. (They took the news that R100 could do 81 mph with 'long faces', according to Nevil Shute.) R100 engineers tried to filangle out of the dour bureaucrats what R101's top speed was, but the officials remained tight-lipped. This flight also saw further investigation on an odd phenomenon. When at flank speed, R100's outer cover developed a standing ripple. Shute and the engineers clambered into the framework to investigate, and found no problems with the attachments. The engineers and riggers concluded that the matter was of no importance, and was probably the result of large eddies of the air as R100 passed through the sky. The Air Ministry bureaucrats grumbled about this, acting like the R100 staff was trying to pass off inferior goods, but Sir Burney shut them down by pointing out the contract called for only a 70 mph top speed, at which the outer cover was fine, and if the matter was so important they could always limit the throttles. This managed to silence the grumbling.

R100 flew by dead reckoning most of the day, and despite a slight leak in one of the engines the flight was otherwise uneventful. The inspection after the flight revealed that the outer cover was already having problems, with many small holes and tears developing. I should mention here that while some narratives have the R100 having no problems, that isn't quite true: it had all sorts of problems, but they were extremely small ones, usually ones that could be fixed in flight, or immediately after. I didn't realize this when writing part one, but R100 bought its engines used from the RAF to save money, and these engines had various small mechanical issues. The standing ripple was one of the only real trouble spots in the R100's development - the outer cover. I know I've repeated this point a few times now, but 'pre-doping' the outer cover in sections just didn't work. The R101 staff by this point had already reached the same conclusion. Another factor here might have been both R101 and R100 having a few large longitudinal girders instead of many small ones like in a Zeppelin design - possibly the British approach was too hard for doped canvas. Anyway, nearly all the flights of R100 were without incident, but you can assume various small fixes with the engines and outer covers were happening after every flight. 

The standing ripples can be seen in this photograph - you can also see one of the RAF chase planes down by R100's tail.

 The aforementioned standing ripple in the outer cover was studied by aircraft on the next flight, January 22nd. A RAF airplane flew alongside R100 and took photos of the standing waves. The cause remained unknown, but for the reasons above the R100 staff did not obsess over it. Speaking of staff, around this time Neville Shute became, all intents and purposes, chief engineer on the R100. Barnes Wallace, the math work done, wanted to get back to Vickers and experiment with geodesic structures for airplanes. (Wallace would have good success with this, the Vickers Wellington seeing service throughout World War 2.) Shute was given the top slot both thanks to his experience with the project and because he was the only head engineer with any flying experience. (Shute was an avid amateur pilot.) 

Acceptance of the R100 required two further flights - one, an endurance flight of forty eight hours, and second, a successful flight to India - which was amended to a flight to Canada instead, the R100 being powered by that recklessly flammable fuel, gasoline. (Was this just a pretext to make sure the R101 was the first ship to fly to India? Probably.)

The R100's endurance flight started from Cardington on the morning of January 27th, with 22 tons of fuel. Major Scott had intended to fly south to Spain, and then make a jaunt out to the Azores - but the Air Ministry restricted the flight to British territory alone. The weather was often vile, consisting of various mixtures of rain, snow and fog - at one point R100 flew 700 ft over Oxford (one R100 length between the airship and Oxfordshire if you prefer) but still could not see the ground. Aside from that, the flight was practically a vacation for the crew. The coast of Cornwall saw a gale force wind, which R100 handled with aplomb, only pitching very slowly 5 degrees to the left, then five degrees to the right. The meals were taken through the galley, and the engineers slept in the little cabins, going to bed at the normal time. Shute reports waking up at two AM, and going down over the control car to see how things were. Turmoil resulted when somebody drank the captain's coca (it was Shute) and then Shute went back to bed.

 Captain George Meager, AFC, reports the same general story, save how at one point problems with an exhaust pipe saw an engine shut off and a mechanic send over the side in a makeshift sling to effect repairs. I didn't realize this until now, but the British also had implemented a primitive wireless direction finding system that R100 could use over Britain for navigation. Wireless Telegraphic Direction Finding (the so-close to comedy acronym WTDF) almost always provided accurate navigation fixes, useful when you can't see the ground. There was also some early attempts at technology that could draw broadcasted weather maps, dubbed a Fultograph. This worked less well, but still, cutting edge stuff for 1930.

Left: a bottom view of R100, the square things are ventilators. Fresh air was brought in from the outside, not only for the living spaces but to keep air circulation around the lifting cells, to whisk away any leaking hydrogen. The Right is a mechanic in what I think is called a bosun's chair, fixing an exhaust pipe at 1500 ft.

 Morning found the R100 approaching London, where according to Shute, the pollution began to leave great soot-streaks on the outside of the airship. The only thing made out on the ground that day was London's Tower Bridge; for the rest of the day R100 flew on without land, er, spot. By the time darkness fell, the wandering R100 had made its way out to Eddystone Lighthouse, south-west of Devon, which they used as a central pivot for about an hour for a series of turning trials, possibly to the bafflement of the lighthouse keeper. That night R100 flew the channel, at one point making an excursion out to the Isle of Scilly, off the southwest tip of England. The next morning, the R100 flew up Bristol channel, and made it back to Cardington by mid-afternoon. The flight lasted some 54 hours.

Sometime during this flight, Shute did something  you really just can't do on modern airliners: he went on deck. The bows had a hatch for forward observation and docking, and running back from this door was a gangway of plywood covered in canvas. The initial part of this gangway was angled upward about 45 degrees, and you had to crawl on your hands and knees. When on hands on knees while under way, a medium breeze could be felt. Sitting would put your head (depending on your height) into a stronger wind. Standing up would expose you to a strong gale. Shute preferred to stay on hands and knees (I can't blame him) while the riggers were quite used to walking into or away from the gale holding onto the lifelines. Sir Burney somehow lost his pocket-watch while up on deck one day, and it remained up there all night, where it was found the next day by a rigger.

The top of R100 while in flight. The line on the left is the lifeline over the gangway.

 These test-flights revealed more flaws in the outer cover. Not only did it rip from time to time, it couldn't keep the weather on the outside. Precipitation tended to make the front part of the ship rather wet. This was an issue both thanks to the cow-intestine lifting cells and many interior surfaces using cloth for walls. Now that I've read about it a fair bit, the Airship R100 was also remarkably...ship-like in some ways. As with the R101, engines were driven by ship's telegraph, with men in the engine pods actually throttling up and down depending. When taking off, it was the job of ship's riggers to make sure the flobbery lifting cells, (set to a pressure height of 4000 ft at thus near the ground only partially inflated) didn't get hooked or snagged in unfortunate ways over gangways or catwalks, which were of course just a framework of girders. They even kept watch as on a Navy ship, right down to the dog-watches (so called because they are 'cur-tailed', har har! Any Master and Commander fans here? No? OK...) Also like a ship, the amount of manual labor needed to keep small problems in check was often considerable. The actual work of checking things or repairing the outer cover up in the superstructure required lots and lots of climbing. What's more, 24 hour watches had to be kept when an airship was docked at a mast: weather changes required trim adjustment from whomever was on duty. This is not a problem in, say, an Airbus A380.

 Both ships were also a bit cold - they relied on ventilation both in cabins and over the lifting cells from outside air. This air was obviously rather cold - as it came from several thousand feet up - to the point that the crew was issued jackets made from teddy bear fleece. In passenger service I think this would have been something of a problem - but you could always remind your passengers to dress warmly, I guess. Flying a seven-hundred foot airship had its oddities as well. Turbulence could be somewhat negated by the rudder-man feeling its effects at the front of the massive hull, and correcting for it before it got to the back of the airship.

After the endurance flight further modifications were made in anticipation for a flight to Canada in May. A minor handling accident required repair, and then it was decided another test flight was advisable, just to confirm all the fixes and modifications were shipshape. On the 20th of May this flight happened, taking off at 7 PM. After flying through the night and most of the next day, somebody noticed the tip of R100's tail was hanging off. Landing, the flight crew consulted with the engineers, who had for reasons they didn't understand has some math that predicted strong aerodynamic forces at the tip of the tail. The engineers had figured this to be a mistake, until this latest flight saw the aforementioned forces crushing the tail's tip. The solution was: get rid of the tail tip. This flight also saw a new captain at R100's helm, Squadron Commander Booth, who managed to land in good time despite squalls and thunderstorms at Cardington.

During R100's test flights, one final card was played by the R101 staff in an attempt to delay the R101's flight to India. The RAW staff quietly suggested to the R100 team that the program was moving too fast (without going into details), and neither airship should make a long distance flight in 1930. The R100 staff viewed the proposal very dimly. As far as they were concerned, their airship was good and ready for its flight to Canada; if the R101 couldn't fly to India, well that was the whole point of the competition, wasn't it? Shute suggests in his biography later that had the R100 staff known the depth of the problems on the R101, they might have considered it.

Towards the end of July, R100 made another flight of 24 hours, just to make sure everything was shipshape. Once again, flying in the R100 was something of a relaxing vacation for the crew, and there were no problems; in fact, both my first-hand accounts mention that the flights were so uneventful as to be boring.  R100 returned to the mast at Cardington on Saturday. The following Tuesday was when she would depart for Canada. 

R101 - Back to Goofus

So the R100 program managed to remain drama free, thanks to storytelling inertia. By that same force (that I just made up), the R101 managed to be filled with difficulties. Despite that R101 would remain in her hanger till June, the problems discovered during her test flights festered. None of these problems (save R101 being overweight, inferred by the planned modifications for extra displacement) were known by even the R100 team, let alone the general public, until after the program was over.

To start with, the outer cover. R101 engineers had examined her outer cover, as mentioned, once she had been hung up and deflated, and seen the same problems the R100 had seen. They decided a redo was in order, with a new outer cover applied Zeppelin-style, IE fitted then doped into place. The Air Ministry refused on the basis it would put the project further behind the R100. Engineer Michael Rope then decided to do some strength tests on the existing cover, and found yet more bad news.The strength of the outer cover was supposed to be 10 kN/m - and for reasons unknown its strength had degraded to, at best, 1.24 kN/m. The force of the air with R101 running at top speed into a wind was 2.09 kN/m. This force would increase further if there was, say, rain.

The lifting cells were also expanded as discussed last time, as was the padding of the girders to try and solve that chafing problem the lifting cells had. The expanded cells did provide more lift, but, as Engineer Rope predicted, letting out the lifting cells made them considerably more prone to chafing.

The R101 came out of her shed again only in the third week of June, 1930. She was hauled out on a humid and calm June morning and docked at the mast. Then, despite the light breeze, the outer cover began to flap in the wind, which quickly developed into a tear 100 feet in length. The cover was now trying to peel itself off of the R101 like a banana. An emergency team of riggers was sent up the docking tower, with rubber shoes and needle and thread, to try and stave off disaster. Climbing through and on top of the outer framework, the riggers managed the job, but only just. (A second, 50 ft rip happened in the outer cover that afternoon, making for a lively day.)

It was clear that the outer cover badly needed replacement, but now there was no time - the Hendon Airshow was June 28th, and missing such a high profile publicity flight was unthinkable to the Air Ministry. A bodge fix was devised in the form of strengthening bands around the nose and tail. A quick flight of four hours was made the day after, just to make sure the bodge fix would last through the airshow. The cover presented no problems, but landing did - R101 launched from her mast mid-afternoon, when her lifting cells had expanded thanks to the afternoon sun. Coming back in the evening made R101 much heavier - to the point that she ejected not only water ballast but two tons of fuel-oil to land properly. Even without an engineer's appraisal, it seemed that R101 was still flying heavy - even though she had been lightened.  

 Despite these dynamic problems, R101 managed to participate in the rehearsal for the Hendon airshow. On the 28th of June, the first officer was Captain George Meager. He was a old hand at LTA flying - in addition to Naval Blimp service in the war, he had flown for Britain in the Gordon Bennett Balloon races, as well as his involvement with the Imperial Airship scheme. The flight to Hendon was without incident, and the R101 appeared exactly as scheduled to dip her nose for the King and Queen, in attendance. The flight back (once again, in perfect summer weather) is when things became a bit spooky. Meager was in the control gondola supervising, and he noticed the R101 was for some reason having problems holding altitude. The airship would go into a short, sharp dive, and then level out, and the coxswain would slowly take her back to her original altitude - until the short sharp dive happened again. Meager mentions to the Coxswain that the ship seems heavy, and the Coxswain replies "it's all I can do to keep it up, sir." Meager now notices that Coxswain is sweating bullets, and so Meager drops a ton of water ballast - and this soothes the Coxswain and R101.  When the Captain 'Bird' Irwin came to relieve Meager at 18:00, Meager opined that the ship was unusually heavy, and that a landing should be made at Cardington immediately, before the heat left the lifting cells. Irwin  was dismissive of Meager, saying it had just been a bit bumpy. Meager went off to supper, and might have been a bit smug when R101 landed at 9 PM, after having dumped some ten tons of fuel and water ballast. (The guy who cleaned up the previous mess of fuel-oil must have been pleased.)

Meager knew that the airship must have been flying very heavy indeed; in his estimation the R100 after the afternoon's flight would have been so light that valving gas might have been necessary to make a graceful landing. The only explanation was that R101 was leaking lifting gas. He brought it up with his superiors, who were dismissive of him, as Captain Irwin had been. So, Meager told his superiors that unless specifically ordered to, his days of flying on the R101 were done.

Meager was right; R101 was leaking gas. Her lifting cells, now expanded beyond their original design spec, were now finding all sorts of new objects to chafe against. Shute estimated that R101 at this point in her flying career was loosing as much as a ton of lift an hour, just from her gas valves venting and her lifting cells leaking. In the following days the a Mr. F. McWade, chief inspector of the Aeronautical Inspection Directorate,  was so concerned he wrote to the head of his department directly, a Col. H.W.S. Outram. In his letter, McWade wrote that leaking hydrogen was a really, really bad thing, and that the solution of padding was inadaquite. Firstly, because the lifting cells moved around far too much for padding to really be effective, and second, because the padding was soaking up moisture, which could create corrosion issues, as well as adding extra weight. The lifting cells, replaced a few weeks ago, were now so damaged it was likely they would have to be replaced again. McWade recommended no further flight-worthiness certificates be issued [IE the air permit to fly allowing R101 to have test flights] until this problem was fixed.

Col. Outram despite his position knew nothing about airships. So, he consulted the expert on airships in the Government service - IE Col. Colmore, head of RAW and one of the big brains behind R101. As if this was not bad enough, Col. Colmore knew that Lord Thomson, air ministry head, had just announced he was going to fly the R101 to India in September and be back in time for the Imperial conference on October 15. As it was, getting R101 airworthy for the India trip would require a minor miracle. Another delay, (especially one where R101 was literally deemed unsafe for flight) and who knows what Lord Thomson would do. So. Colmore wrote back to Col. Outram, saying that there was nothing really to worry about. There was some leaking of hydrogen, but all airships did it to a degree, and the padding protocol would be a permanent fix. (Nevil Shute speculates that Col. Colmore might have also implied McWade was being a nervous old woman about the whole 'hydrogen mixing with oxygen' thing.) Col. Outram wrote back to McWade a week later after getting Colmore's opinion and consulting with McWade, and told him he was going to keep issuing flight certificates. "The only thing to do now is to pad...it is your job to see that every point is padded correctly." His duties clarified (and his points about the padding completely ignored,) McWade gave up. This was a total failure of the supposed outside objective regulators for the Imperial Airship Scheme.

Still, there was a little hope: on June 29th, R101 started her upgrade. The main job was the addition of a new center section, containing a extra 500,000 cubic foot lifting cell. In displacement terms, the cell by itself displaced the same as a Great War M-class Zeppelin - the press at the time reported it couldn't be fully inflated inside Westminster Abby. It was hoped such an addition to displacement would allow the R101 be able to fly in tropical climates. Much, but not all of the outer cover was replaced. Two sections (around the tail and a segment toward the bow) had been doped after being fitted, and were judged to be holding up well. It turns out that the area treated with the unfortunate glue was in fact the forward sections, and it is possible some of the glue-contaminated outer cover was left in place because of this economizing. The engines were also upgraded with the magical ability to reverse, meaning the fifth engine could now be used in normal flight. It was hoped the fifth engine would even out the gain in R101's displacement. Several (but once again, not all) of the lifting cells were replaced. The deadline imposed by the Air Ministry loomed large in everyone's mind. From June 29th on, RAW worked three shift 24 hour days - and even then, the work was going to take until the third week of September. Still, the work was not entirely bad. When R101 was divided in two, her lifting cells were left inflated, so moving the two sections was a simple matter of pushing them apart to make space for the new section.

While this was going on, R100 was preparing for her flight to Canada, where her slight tail flaw was seen as possibly something that might prevent her from making the flight. Later, people would report Lord Thomson's attitude toward such possibilities - if R100 had problems with her tail, the flight would be delayed or put off - while nothing would stop R101's India flight in September. The interval between finishing R101's refurbishment work and when Lord Thompson wanted to depart that The Air Ministry allowed only one test flight to happen before the India flight.

Some notes here.

 As the independent safety adjudicators were telling the Air Ministry, R101 had not done enough test flying according to the Air Ministry's own contract to be ready for the India flight. The contract specified a successful 48 hour endurance flight before flying to India, and the best R101 had done so far was 24 hours. The R101 furthermore had gone backward in its safety certification: the major surgery R101 was getting negated the safety work done thus far. Once again, under the Air Ministry's contract, the R101 was supposed to have been mathematically proven to have a sound structure before being accepted. Now, all that work had to be done again, as well as a top speed test, which thus far had never been done officially. The independent safety people had also mentioned to the Ministry that while not strictly part of the contract, you really should try to fly R101 in bad weather before accepting it for passenger service.

This mattered not at all to Lord Thompson. He had made his plans, and 'they could not be altered' - so R101 was going to fly to India without doing basic flight testing.

Next - R100's Big Day Out

Part of the a series of posts on the Imperial Airships.

Part 1

Part 2

Part 4

Part 5