The Story of R100 and R101 I - The Imperial Airship Scheme

The conquest of the air will prove, ultimately, will prove to be man's greatest and most glorious triumph. What railways have done for nations, airways will do for the world. - Claude Grahame-White, The Aeroplane, 1914

Longtime readers of this thread will be unsurprised to learn that I've spent literally some time thinking about the trends that lead to airships falling out of use. Some of these you are no doubt familiar with (viz. the incredible advances in aviation made during World War 2, the enormous civil engineering project of building modern airports around the world thanks to World War 2, hydrogen being dangerously flammable when mixed with air, etc.) I came across a new idea while researching this new infodump, from a British aviation writer in 1929: "Airships breed like elephants, airplanes breed like mice." This is true. Rigid airships need to be very large to justify themselves over other Lighter Than Air (LTA) designs, which meant that getting into the rigid airship game is very capital intensive. This in turn meant far fewer people would be messing around with rigid airships. Further, big investment upfront meant that large airships had to have some viability almost immediately, and setbacks (particularly exploding setbacks) had a big impact on further development. Airplanes, in contrast, were fast, cheap, and frequently out of control. Many early aviation pioneers were people who were mechanically skilled and loved the idea of flying and airplanes. Setbacks might well be terminal for one man's effort, but many others were ready to take their place .In evolutionary terms, the failure of one line of airplanes had little impact - while with rigid airships, it was enormously significant.

This is especially relevant in the story of the R100 and the R101. The United Kingdom's final attempt at making rigid airships, one was a success - an unqualified success if you consider how much industry had to be developed just to support the endeavor. That didn't matter, unfortunately. The other airship was a titanic failure, almost literally: it failed so disastrously, and in retrospect for such obvious reasons, that it kept the word "hubris" in circulation for another decade, at least. In the face of that, the success achieved meant little.

So here is the story of Britain's real liners of the air. It is a tale of the challenge of developing new industries, British politics, some rather amazing flying machines, and an ending that is like the Titanic, except with much more exploding.

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Great Britain had a long standing interest in rigid airships, one that predated World War 1. Part of this was probably due to envy of German Zeppelins. Britain had been the technological pioneer of the last century, and they didn't like seeing another nation forge ahead in a new, possibly lucrative, field. Another factor may be that while Britain seemed to initially under-appreciate the possibilities of airplanes (the first airplane flight in Great Britain only happening in 1908) they seemed ready to grasp the possibilities in airships. I think culture might have been a factor here; the Edwardian mind was used to steam ships and railways, and the idea of a ship of the air was just an easier conceptual fit than balsa wood insects generating lift through the math in their wings. (To be strictly fair, I think one of the reasons I find airships fascinating is that they fly with principles that I can easily grasp; while I understand the basics of aerodynamics, there is a lot in airplanes, especially modern ones, that I don't understand.)

The other reason for Britain's interest was a lot more practical. As soon as Count Zeppelin's experiments proved viable, airships were seen as a possible way of strengthening Imperial communications. The British Empire was the envy of the world thanks to its wealth and size, and anything that helped administer it was seen as a valuable technology in the eyes of Britain's ruling class. This determination soon percolated through the aristocracy, where it found a willing ally, in the form of Vickers Shipbuilding. The new airship technology seemed a natural fit to Vickers existing skill-set. 

In this the government and Vickers were wrong. The first attempt the British made at a rigid airship was a comical, rather than tragic, disaster. Vickers got the Government in 1912 to underwrite the first British airship. Using a group of engineers who previously had designed a submarine, the airship was certainly ambitious: His Majesty's Airship Hermione was at the time  the largest aircraft in the world. She was 156.1 m (560 ft) long, and 14.6 m (46 ft) wide. Her displacement was 660,000 cubic ft,making her roughly the size of the early German Naval M class Zeppelins. Unlike those Zeppelins, the HMA Hermione was outfitted lavishly on the inside, with fine mahogany woodwork and a ship's anchor, and was originally envisioned to be a Naval scout for the Royal Navy. The crew was 20, and her two engines made about 160 hp. I think that's a little low for such a big aircraft, but we'll never know: crosswinds caused her keel to snap the first time she was removed from her shed. Managing to get the now ruined airship back inside the shed, the wreck mouldered inside for a year after, while lawyers for Vickers and the Government argued over who should pay for the useless wreck. 

 

Before and after HMA 1. Not pictured: good engineering.

The gnawing skyship ambitions of Great Britain was further fed  by the First World War. The conflict saw the UK both attacked by rigid airships and finding themselves in possession of quite a few wrecked Zeppelins. Many experimental airships were built, but most never saw operations; the British had notable success with blimps instead, using them for patrol and anti-submarine work in the North Sea. These were robust and simple designs, usually with a lifting cell, a gondola beneath for the small crew, and a aircraft engine suspended on cables behind. In contrast, attempts to build rigid airships usually were never used operationally. British rigid airships did manage one extraordinary success after world war 1: in May 1919, the RFC airship R.34 became the first aircraft to fly across the Atlantic and return, a month after the first flight across the Atlantic by Alcock and Brown, in a Vickers Vimy bomber. In addition to setting a new endurance record for aircraft, this flight was more evidence at rigid airship's talent for extremely long flights, which the Germans explored during the First World War. By the 1920s, the airship developments were happening all over. The Norge, a Italian-built semi-rigid, had flown over the north pole with no less a personage than Roald Amundsen aboard. The French Dixmude (an ex-German Naval Zeppelin) had made long flights over France's North Africa colonial possessions  before an unfortunate encounter with a thunderstorm. The Americans were getting in on the act as well - with their unique supply of helium and good relations with Germany, the US navy was going into LTA flight in a major way, and this included rigid airships. The USS Shenandoah (ZR-1) would be launched in 1923, and the Americans had also commissioned the Zeppelin company to build them an airship that would become the USS Los Angeles. (ZR-3). It was an exciting time for airships, and the British government didn't want to get left behind.

This was despite the fact the Royal Navy had given up on the idea. The Royal Navy had an alternative in the aircraft carrier, which had been developed during World War One to fight German Zeppelins. The R38 disaster, too, had soured the Royal Navy on rigid airships in general. The R38 was a copy of late war German Zeppelin designs, started during World War One. Made to patrol the North Sea, it was completed at the behest of America, who wanted to buy it. In August 1921, with an American crew aboard, the renamed ZR-2 was test-flying over Hull when she broke in two and exploded. 44 men died in the wreck. The cause of the disaster was that British engineers of the Royal Airship Works had copied the "height climber" design without realizing that Zeppelins of this type were designed for lightness, to the point that they could actually warp their hulls with sharp maneuvers at low altitude. A ton of weight was also added to the design at the bow and stern without any reinforcement amidships, so that the R38 could use docking masts. When the disaster occurred, the crew was testing the maneuverability of the R38 by doing lock-to-lock turns at full speed. As if this was not enough, the official inquiry found that the R38's engineering staff of  incompetence: at no point had they tried to calculate the effect of aerodynamic forces on R38's structure. (This inquiry was charted to analyze causes, not place blame, and the engineers behind R38 suffered no censure for this failure.) So unlike other nations, if the British wanted rigid airship airliners, it would have to be developed by civilians.

Charles Burney and his hydroairplane.

The man who got this effort going was an MP named Charles Dennistoun Burney. His father was a Admiral with Jellicoe at the Battle of Jutland, but the Admiral's son was an inventor. An officer in the Royal Navy, he took frequent breaks in his career to work on new ideas. Before the first world war, he worked on a flying boat with a hydrofoil undercarriage. His most famous invention was the Paravane, during the First World War. A kind of underwater kite, it could be tethered to the bows of a ship, where it would sweep out parallel to the ship, and snip the cables, or just set off, underwater mines. Independently wealthy thanks to this invention, he stood as a conservative MP from 1922 to 1929, where he put together a proposal that airships be used to connect the far-flung corners of the empire. 

It's clear that Burney was somebody who could grasp the possibilities of technology: the 1920s airship was mature enough in theory to fly these route. Still, it was a highly ambitious plan. Not only was it proposed airships be built for these globe spanning routes, the idea was that the airships be British as well. Burney was in effect trying to found a new industry, and develop it to the point British companies could profit from it. He was also proposing that the government develop infrastructure for international flights. These airliners would need staggeringly gigantic hangers for maintenance, as well as docking masts, hydrogen plants, and other facilities to service them. On top of this, weather forecasting would have to be done internationally - the first time anybody had tried to coordinate such a thing. 

There was also the challenge of actually flying these routes. Airships (like other aircraft) do better in temperate and cold air rather than warm, and India was the key route of interest to the British Government, a notably tropical place. Desert flight in particular was tricky for airships, as extremes of night and day temperature made ballast management challenging. Flights over mountains posed additional dangers. The sudden air pressure changes on either side of a mountain range could take a airship in perfect trim and put it wildly out of trim - far too heavy or far too light.The framers of the plan seem to have anticipated this, and planned routes went over the sea whenever possible. 

Despite (or maybe because of) the scope and depth of its ambition, Burney's proposal was popular both with the public and with Government. That said, the Conservative Government at the time was in no great rush to implement it. The idea was studied by no less than 9 committees, which may be slow walking the idea, but at least produced lots of detail as to what hypothetical skyways would need. As the idea drifted through circles of poshness, Vickers was once again chosen as the private partner. At this point, the scheme was very simple: the government(s) would construct all the infrastructure required, and Vickers would design and build six airships, and form a company to operate them. 

All this sounds like the stuff of steampunk fantasy today, but at the time this decision made perfect sense. When the plans were laid, not only were aircraft not flying across the Atlantic, famous aviators like Charles Nungesser were dying in attempts to do so. Meanwhile, an Airship had made it out and back again on its very first attempt. For long distance flying, airship technology was handily superior to the airplanes of the time, as was airship payload capability. Airship travel would also be much faster than other travel options at the time. Travel to Canada was not all that bad - this was the peak of the era of trans-Atlantic Ocean Liners - but such a voyage could take a week, where an airship flight would take three days.The rest of the British Empire had much longer travel times. A flight to India on Imperial Airways' initial service took twelve days, and lord only knows how many stops.* This was not only expensive, but took a stern constitution. For people lacking in either of these, there was the Ocean liner - much more comfortable, but taking six weeks to get from England to India. To get to Australia was even longer. Airships could fly to India not only faster than aircraft at the time, but the three to four days journey could be taken in train-like comfort as well. In many ways, the Imperial Airship scheme was the Concorde program of its day. *I should mention that around this time, not generating the same amount of headlines as competitive airship building, the British government also began subsidizing formerly private airlines to strengthen Commonwealth lines of communication. First gathered together under the name Imperial Airways, this airline would become the British Overseas Air Corporation (BOAC) in 1939, and lives on today as British Airways. (But they were never into airships so who cares)

  British politics then sidelined the idea. The Conservative party, approving of the plan in principle but having not signed anything binding, lost the election in late 1923, and it took a year of political scrimmage before a new ruling party emerged. In late 1924 the Labor Party under Ramsey MacDonald emerged as the victor. This was the first time the Labor party had won control of the government, and the first time labor put a Prime Minister in office. A new Air Minister was appointed, Lord Thomson, who had a special interest in airships and the Burney scheme.

Christopher Birdwood Thomson was a interesting character: he came from a British Army family, with both his father and his grandfather on his mother's side being generals in India. Despite his aristocratic background and a private school education, his advancement in life was mostly his own doing - Thomson had a gift for seeing opportunity where others saw problems. A British Army engineer as his father had been, Thomson soon learned the key for dealing with his social betters: do whatever they wanted, regardless of the problems this would cause. This problem-solving knack distinguished him in the eyes of his superiors, and his first job in World War One was the plumb assignment of serving as interpreter between the initial commander of the British Expeditionary Force, Sir John French, and General Joffre, head of France's forces. He was also dispatched to Romania, where he acted as a military adviser to Romania's disastrous joining of the Allies. He also found time to romance and marry a genuine Romanian Princess. He was then dispatched to the Middle East, where he once again distinguished himself at the Battle of Jericho. Part of the official British delegation at the Versailles, he found himself completely objecting to the treaty on the grounds it was in his view sowing the seeds of another war. This sparked an interest in politics, and despite being from a traditional Conservative background, he found himself standing as a Labor MP. That Ramsey MacDonald was a personal friend of Thomson was likely part of this, though it was also a shrewd political move: by getting on the Labor train early, he was considered for much higher positions than he otherwise would have been. In the election that created the Labor Government, Thomson had stood for election and lost, and was made a peer so he could become Air Minister. (Under the Westminster Parliamentary system, anybody serving as a minister in the government's cabinet has to be a MP or a peer.)

The new Lord wasted little time. The socialist elements in the Labor party never liked the Burney scheme's reliance on private enterprise, and in the Westminster parliamentary system any scheme not set in stone, almost by definition, had to be meddled with, least the other party get credit for a successes. Lord Thompson and the other distinguished gentlemen had a lot of meetings, and came up with a odd compromise. Known as the Imperial Airship Scheme, they proposed a contest. Vickers would build a airship using private enterprise, the R100. At the same time, the Government would demonstrate the superiority of government controlled industry by constructing a rival airship, the R101. Whoever built the best airship would build the remaining four airliners for the Imperial Scheme.  As far as compromises went, it was original, one must give it that. It was also something that seems seems to have had ex post facto rationales later attached to it, like getting greater efficiency via competition instead of single-sourcing, and the hedging of technological bets, for if one ship proved a failure the scheme could rely on the other. But the initial motive was purely political. At any rate, the competition proved extremely popular with the press, who loved a good horse race. The plan was also very popular with the public; as the airships were constructed, the enthusiasm the general public had for the airships was if anything like the space race in the 1950s and `60s. The R100 was dubbed the 'Capitalist' airship by the press, and the R101 the "socialist" airship. 

The initial specifications as drawn up by government committee were very ambitious. The airships were to be at least 5 million cubic feet in displacement, with a upper limit on gross weight of about 90 tons. The gross lift weight was aimed to be about 62 tons, and subtracting the weight of the crew, stores, and water ballast (30 tons) gave the theoretical airships a useful payload of 42 tons. These airliners were to have a 100 passenger capacity, and fuel for 57 hours of flight time with a cruising speed of 63 mph (101 km/h) and maximum speed of 70 mph (110 km/h). They would also need good reverse speeds, as experience with docking masts had shown them necessary. The displacement figure is especially notable, as it is twice that of the largest airship constructed at the time.  One question I can't find addressed in my readings is if helium was ever considered as a lifting gas instead of hydrogen. If it ever was, it seems to have been rejected almost immediately. While cost would have been prohibitive, an even larger objection would have been logistics. Hydrogen was easy to manufacture anywhere in the world, while Helium would have been transported (somehow) from the United States to "all over the British Empire", which was a lot of places.  

The R100 effort was headed up by Burney, who once again showed how unusual he was as a politician by proving to be a able manager. His chief engineer was Barnes Wallace, a name that might be familiar to AI: he was the British engineer who would go on to design the Wellington geodesic bomber, the bomb used in the famous "Dambusters" raid of World War 2, and the giant "Tall Boy" and "Blockbuster" gravity bombs. While apparently these two men would argue constantly, they made a remarkably effective management team. Barnes Wallace's right hand man and chief calculator (IE the engineer in charge of calculation) was Nevil Norway, more famous to the world under his pen name, Nevil Shute (1899-1960). Later author of such books as "The Sky is No Highway" and "On the Beach", Shute's account of the airship program in his autobiography Slide Rule is a real gem - abet one that still attracts controversy.

Know this, readers: in the airship-books I read there is considerable argument about the R100 and the R101, and the merits of each. Shute is very unusual in that he was at one point the head of engineering for the R100 project, and also wrote the most famous account of the R100 and the R101 by a order of magnitude. This, combined with some shocking thing to say about the R101's engineering staff, has lead to charges of "bias" with his account of the R101, with a very firm "R 101 was not in fact terrible" camp forming in opposition to it. Defending this position is a little more difficult: when you are reduced to writing things like "the crash, explosion, and resulting inferno did little damage to the structure, showing how well built it was" your case might not be very strong. At any rate, while Shute later regretted writing that R101's engineers were incompetent, his account of the R101 itself holds together these many years later. Perhaps if you are interested in airships, you are a bit of a cross-grained contrary sort to begin with, so that would explain R100 defenders. (Or perhaps the pushback is because none of the central characters of R101's story ever wrote a book defending it, because they all mysteriously died around the same time in 1930.)

The head of engineering on the R 101 was Lt. Col. Vincent Richmond, a engineer who from the start of the Great War in 1914 had been involved with British LTA projects. He had no administrative other: rather, he reported to the bureaucrats of the Air Ministry, and ultimately to Lord Thompson. This introduced two difficulties to Richmond's life almost immediately: the people giving him directives were not technically educated -and as a result some very basic decisions were taken for political, rather than engineering reasons. Another problem was that the people in the Air Ministry were in no way experts in airships. With every single British airship-savvy engineer already engaged on the Imperial airship scheme, the Ministry would have to consult the people they were supposed to be supervising for advice - which even with a good will was obviously a problem. The bureaucratic administration would have a more insidious problem as well: information flow became rather murky once it passed over to the political side, with many important memos seemingly going unread, or at the very least, not acted upon. Barnes and Burney might have been argumentative, but there was no disagreements whatsoever about who was in charge of what - if a problem developed, the management team on R100 could (and did) take decisive action. 

The R101 project was given a rather spectacular adjustment to counter these problems: an unlimited budget, with the engineers of the Royal Airship works being given free reign to develop whatever new technology they wanted. As a result, the two projects immediately took on very different characters. The R100 became a simple attempt to build an airship to the contract specifications, where R101 sought to fulfill the specifications and push the boundaries of airship technology. The competition also rather sharply divided the two engineering teams, with very little, if any sharing of information. The R101 team thought of the R100 as a fig leaf to keep the Conservatives from complaining. Meanwhile the R100 team only heard of developments on the R101 through the frequent press releases of the Air Ministry. Amazingly, the only group who got a close examination of both projects was the Zeppelin Company. Despite the fact the government was doing this whole program in part to become rivals with the German firm, Zeppelin company officials were granted much freer access to both programs then British engineers on the rival teams.

The Un-Photogenic Years

By 1925, the plans were set. The government released a timetable for the project that now - even at the time - was optimistic to the point of delusion, saying flights to India would start in a year and a half, in 1927. As it was, this is about how long the theoretical work of R100 took; R 101 took even longer. As Shute wrote later, the sheer novelty of the engineering challenge required "to attempt to build an airship from first principles alone, guided only by sound theory and calculation." The Air Ministry had additional requirements for the engineers to consider, as well. Two certification committees - independent of the government - were formed. All consisted of mechanical engineering professors - one committee (names) would be in charge of certifying the structure of the rigid airship as safe; the second would be for certifying that the airships were in fact safe to fly. In addition, the Air ministry stipulated that only the transverse girders bear the weight of the lifting bags alone, with the longitudinal girders being sheltered from such burdens.

The fear of the bureaucracy was (among other things) another R38 type disaster, and went to elaborate lengths to make sure the framework of both airships was sufficiently strong. It is here we can see the start of problems. The problem with R38 had been incompetent engineering, not just "we need to make the structure stronger." By getting involved with such things, the Air Ministry was meddling in affairs it didn't really understand. Similarly, it was taken as read by the Ministry that the safest engine any airship in the tropics could have would be a Diesel one. Why this was widely thought of as a good idea is a little bit difficult to explain. Gasoline's vapor point meant that in the tropics explosive fumes might be an issue, but the connection between 'aircraft safety' and 'diesel only in the tropics' is a bit baffling - especially when aircraft were already operating safely in India. Honestly, I'm going to chalk this up to technical illiteracy.

So the first year and a half of the R100 and R101 was filled with office work, and the working out of basic details. (I'll be concentrating on R100 this post.) Decisions about R100's construction were made as follows: at first, the engines were initially going to burn an exotic mix of hydrogen and paraffin, but after toying with the idea for about a year, but these were deemed impractical. Diesel engines were also considered for a short time, but was also abandoned, because, well, diesel aircraft engines didn't exist, and adapting existing ones would produce an engine much too heavy. Rolls-Royce Condors, aviation engine with an output of 650 hp were settled on as they were a proven design already in production. Except for the control car and the engine pods, all the airship would be inside the main fuselage. Two of these engines would be able to reverse themselves - British style docking masts solved some of the problems of landing an airship without hundreds of men hauling on ropes, but having a strong reverse was necessary, least in a wind shift the front of the airship be driven into the mast. The only departure from airship orthodoxy at the time was with the outer cover. Zeppelins had an outer cover that was attached and then doped into place. Both the R100 and the R101 designers decided to reverse this process, pre-doping the cover material, and then applying it to the hull , in the hopes that the result would be lighter and/or cheaper. I can't comment on if those goals were achieved, but I can tell you structurally this did not work - both airships had problems with their outer covers ripping, about the only design flaw the two airships had in common. Had the project continued, builders would have adopted the Zeppelin method.

Both airships still used the "gold-beater's skin" - cow's intestines -  to make the lifting cells.
James Leasor in his book "A Millionth Chance" said that from a modern perspective, "the use of these skins seems incredibly anachronistic. They were, in fact, membranes that had formed part of a bullock's intestine known as the caecum, and the method of their preparation and use was crude, messy and almost medieval. First, lengths of this skin, measuring about 35 by 30 inches, were cleansed of all fat in tubs of warm water, and then teams of girls scraped them carefully with blunt knives. They were then stored in tubs of brine until they were needed, when the girls soaked them in glycerine and stretched them onto a great sheet of canvas, still dripping wet, so that their edges would stick together. When dry they were peeled off the canvas like an enormous roll of parchment, and afterwards they were varnished." Both airships required something like a million cows worth of intestines each, supplied mostly by Chicago stockyards.While most of the technology was sourced from British manufacturers, the R100 team choose to buy lifting cell pressure release valves straight from Zeppelin. This was extremely canny of R100`s designers, as pressure relief valves featured in a disturbingly large percentage of hydrogen airship accidents. Like the system for warming air in a modern airliner using turbine exhaust gasses or nuclear reactor's emergency shutdown mechanism, pressure relief valves was one technology that needs to be absolutely reliable, or else bad things would happen.

The biggest activity during this period was math; especially math having to do with the rigid framework. Most of the first year and a half was taken up with the math that had to underpin these decisions. World War 1 Zeppelins were initially cigar-shaped because it allowed this sort of work to be greatly simplified - structural rings were stardardized. This also allowed easier mass production. The R100 and the R101, on the other hand, could not take the easy route, as their designers settled on a gentle ovid shape, with each structural ring being different.  Structural calculations, in particular, required a daunting amount of work in the pre-computer age.  Nevil Shute provided an account of some of these calculations, and I couldn't help but share the entire thing here. (Erm, the uninterested can rejoin the tour after the italics.)

" The stress calculations for each transverse frame, for instance, required a laborious mathematical computation by a pair of calculators that lasted for two or three months before a satisfactory and true solution to the forces could be guerntted. [...] Each transverse frame consisted of a girder in the form of a stiff, sixteen-sided polygon with the flats at the top and bottom; this girder was twenty-seven inches deep and up to a hundred and thirty feet in diameter. Sixteen steel cables ran from the center of the polygon, the axis of the ship, to the corner points, bracing the polygonal girder against deflections. All loads, whether of gas lift, weights carried on the frame, or shear wire reactions, were applied to corner points of the polygon, and except in the case of the ship turning these loads were symmetrical port and starboard. One half of the transverse frame, therefore, divided by a vertical plane passing through the axis of the ship, consisted of a encastre arched rib with ends free to slide toward each other, and this arched rib was braced by eight radial wires, some which would go slack through the deflection of the arched rib under the applied loads. Normally four or five wires would remain in tension, and for the first time approximation the slack wires could be guessed. The forces and bending movements in the members could be calculated by the solution of a lengthy simultaneous equation containing up to seven unknown quantities; this work usually occupied two calculators about a week, using a Fuller slide rule and working in pairs to check for arithmetical mistakes. In the solution it was usual to fine a compression force in one or two of the radial wires; the whole process then had to be begun again using a different selection of wires. 

When a likely-looking solution had at last been obtained, deflection diagrams were set out for the movements of various corners of the polygon under the bending movements and loads found in the various portions of the arched rib, and these yielded the extension of the radial wires under load, which was compared with the calculated load found in the wires. It was usual to find a discrepancy, perhaps due to an arithmetical mistake by a tired calculator ten days before, and the calculations had to be repeated till this check was satisfied. When the deflections and the calculated loads agreed, it was not uncommon to discover that one of the wires thought to be slack was, in fact, in tension as revealed by the deflection diagrams, which meant that the two calculators had to moisten their lips and start again at the very beginning. 

The final check was to take vertical and horizontal components of the forces in every member of the frame to see that they equated to zero, that your pencil diagram was not sliding off the paper into the next room. When all the forces were found to be in balance, and when all deflections proved to be in correspondence with the forces elongating the members, then we knew that we had reached the truth."

Sky Cathedral of Howden

While the British  government framed the Imperial Airship program as an experiment in political ideology, they were not above putting their thumb on the scale to advance the socialist team. (In truth, the judge of this contest was also one of the two competitors, so it was pretty much the opposite of a fair competition from the get-go.) As noted, the R101 team would have an unlimited budget, and in another advantage would use the the Royal Airship Works at Cardigan, in the industrial heart of Great Britain. This guaranteed the Royal Airship works easy access to as many skilled laborers as they needed, as well as being conveniently close to likely subcontractors. The R100, in contrast, was given an abandoned airship base in northern Yorkshire, at Howden. The R100 team was in for a bit of a shock when they came to the old Howden base in spring 1926. Howden in the last century had grown rich on horse-trading (really, it was the export point for Yorkshire horses to continental Europe) but had become a fading town of run down manor houses. The airship base itself was 3 miles outside of town, in abandoned fields, with a giant hanger looming over the collapsed wrecks of lesser buildings. The hanger was 170 ft, or 17 stories high on the inside, and could house two 750 ft airships with a beam of 150 ft. Seven acres of floorspace gave the hanger a open feel. The first order of business for the new tenants was to drive out all the animals. Howden base had been abandoned at the end of the Great War, and the hanger was now home to innumerable birds and rabbits. A fox had her den underneath the floor, where the hydrogen and water mains were. Once all the animals were gone,  some effort was made to make the hanger weatherproof. This was less successful: rain, snow, and fog were frequent inside the hanger while R100 was being constructed.

Setting up shop in Howden posed more problems for Vickers. First, the local workforce was a bunch of farmers and miners - unlike the R101, the R100's workforce would have to be trained how to work in an industrial setting. The workers mostly proved satisfactory, according to Shute, though he did find the women workers appalling.  "They were brutish and uncouth, filthy in appearance and in habits [...] I can only record the fact that these girls straight off the farms were the lowest type I've ever seen in England, and incredibly foul mouthed. We very soon found we had to employ a welfare worker to look after them because promiscuous intercourse was going on merrily in every dark corner, and we picked a middle-aged local woman thinking she would know how to deal with problems that we had not contemplated when we started in to build an airship." Another pain was transport: this was such a problem that the girders would be manufactured on site. Starting with sheets, duraluminum would be rolled into tubes and then bolted or welded at its ends. For economy reasons, the construction team only used 12 machines. The R100's frame was constructed of just 11 standardized components, making its physical construction like a duraluminum lego. This simplification made engineering calculations easier, as well as construction. In addition, R100 pioneered the use of color-coded wiring as well, to simplify construction and troubleshooting. As each great structural ring was completed, it was rotated vertical and hoisted into place. The rings once secured were 160 ft high, and the work required men to regularly climb up the superstructure like a 17 story tall set of monkey bars. Neville Shute had a fear of heights, but soon became used to clambering about with no discomfort at all. (Despite being an avid pilot most of his life, his fear of heights returned after the project was completed.) The only other structural problem was corrosion. As I've written, the Howden shed was never really weather-tight, and rain, show, and especially fog regularly got inside the shed. The structural girders eventually began to corrode in the precipitation. Wallis made the decision to grind off all the corrosion and varnish all girders. This took a team of 30 men three months, and added nearly a ton to the gross weight of R100, but completely solved the problem.

Esteemed gentlemen have tea while checking up on the R100 project. Some of those rabbit-brained country girls have been dragooned into being waitresses.

The structure was braced with wires, which also performed an important secondary function of holding the lifting cells themselves in place. Shute and several senior engineers supervised the inflation of these lifting cells by climbing up into the works, greatly impressing an official from the Zeppelin company that happened to be visiting. Each bag cost several thousand pounds, so rips could not be tolerated. Even the hydrogen was a considerable expense, it costing several hundred pounds in 1920 money to fill one lifting cell.

The R100 project also had to work in the shadow of the R101. Press releases about how awesome the government airship was going to be was reported all over the UK, and at best the R100 was mentioned at the end of the story as this other thing that was happening. Reading details of the R101 project sometimes caused the R100 staff to doubt themselves: in particular, with the rudder. The rudder on R100, calculations had shown, despite being several hundred square feet, could be handled by pilots without any power assist at all. When it was revealed that the R101 had the latest and the greatest in a very heavy servo motor, calculations were checked and rechecked to make sure their had been no mistake. This issue remained a small neurotic worry to Shute, only banished when R100 flew just fine without the power assist.

By1929, the mighty ship was floating above the workfloor. The entire workforce assisted in `weighing off`the airship, holding it down as weight was added and subtracted so the engineers could find R100`s `zero point`where she was neutrally buoyant. Eventually, the workers released R100 and she very slowly floated up instead of down. The airship was ready to fly.

Then, the Air Ministry stipulated a test: now that the R100 was filled with hydrogen, she would have to test her engines at top speed...while still in the hanger. The R100 staff was against this, but this was a directive from the Air Ministry. These tests Shute would later describe as one of the only times in the R100 program he was terrified. One can understand why. Running all six engines at full throttle, the clearance of the giant wooden propellors was only 30 cm off the floor; and no matter what rigging the staff tried, the airship would surge and twist, and generally test its tethers like a 700 ft long puppy.The noise of six aircraft engines rendered speech impossible. These tests ended somehow without disaster, and the staff settled down to wait for the absolute calm needed to take R100 out of her hanger. The only method they had for this was man-power, and on either side of the hull there was a clearance of 60 cm. (This was a problem, one that Shute worked on in 1930. Given the docking masts, I imagine the solution was some sort of mini-movable docking mast that could be attached fore-and-aft.)

Canada's docking mast at Montreal.

Constructing Additional Pylons

When physical work on the airships actually started, it was time to begin working on infrastructure. One thing airplanes at the time had going for them was that they scaled to the available infrastructure. The populatity of flying boats in the 1920s and thirties was because they simply needed bodies of water to land on; other airplanes could make do with exceptionally large fields. The Imperial Airship scheme, in contrast, was going to require a lot of up-front investment. Including:

1. Docking Towers. Anyplace the Imperial airships would call at would require docking towers of great strength. Each airship was as long as an ocean liner and twice as wide, and would exert quite a bit of force when moored in high winds. The towers themselves stood some 250 ft high. All the airship's consumables - hydrogen, fuel, and water - would have to be sent up the tower, as well as any passengers or cargo.

2. A steam driven physical plant. Docking a airship to these towers required rollers to haul in the bowlines, and more power once the main tether was snagged to the mast. This plant also gave force to the gas and water you are piping 250 ft straight up, and for making electricity. The electricity you will need a considerable supply of, because -

3. -you will also need to construct a hydrogen plant. This is another area the British would have been better off simply consulting with the Germans - for the Germans had an advanced chemical industry, and that know-how was useful when dealing with Zeppelins. Their hydrogen plants were very simple - they took water and ran it over a 700 degree (I'm not sure if that is in C or F) hot iron, which I'm guessing separated the H20 into its constituent elements. The British hydrogen method was much more labor-intensive and I imagine expensive - train cars of (something) were hauled to the hydrogen plant, where the something was processed into hydrogen and toxic sludge, when then had to be hauled away. (I'm sorry, my chemistry knowledge is especially bad.)

This was just for a basic docking facility. You might also want:

4. A 'shed' to keep your airship in so it could undergo overhauls and repairs. I've been referring to these sheds as hangers, for one because the airships actually could be 'hung up' in them. I also think the term 'shed' is a bit underwhelming for the largest buildings in the entire commonwealth; which strikes me as describing the Pacific ocean as 'damp.'

The Karachi airship hanger. A later refugee crisis saw it made home to several thousand refugees.

 Towers were constructed at Cardington, Ismailia, and Karachi, with Cardington also having two R100-class hangers. Karichi also saw a hanger built. Australia and South Africa surveyed locations for towers, but declined to construct them until this new imperial airship service was actually flying.

Canada also constructed a tower. Enthusiasm for the Airship Scheme was immediate once Canada's leaders were introduced to the idea during an Imperial Conference in 1925. After a survey of most of eastern Canada, a site was picked at St. Hubert, just east of Montreal - this was Canada's first international airport. The location was a good choice: Montreal was Canada's industrial and cultural capital at the time. Canada also made a study of the Graf Zeppelin's flights over America, and made provision for crowd control, concessions, and even a branch rail line being built from Montreal's main station to allow easy access to the docking mast. By the time the Imperial airships took to the sky, Canada was the only part of the British Empire outside of the all-important royal road to India ready to receive a big colossal visitor.

 Up, Up, and Away

By the time R100 was finished, she was weighed off, and her builders could see how they had done. She was the size of a Ocean Liner - 219 m (719 ft) long, with a beam of 40 m (133 ft). To put that in perspective, that's about as long as two regulation soccer fields from end to end, or about the same in American football fields. If stood on her nose, R100 would be about 71 stories tall. She displaced 5.1 million cubic feet, who's gross lift was 159 tons. Subtract the weight of the ship itself (105 tons) and weight for consumables like ballast, her crew of thirty, and fuel, (18 tons) and the useful payload was 33 tons. Her first deck was for crew accommodation. Her second deck had 18 four-berth cabins, and 14 two berth cabins on an upper deck, giving the R100 room for 100 passengers. These passengers had a lounge, a smoking room, and many promanades to look down upon the world with. Her range was variable depending on payload, as with all aircraft, but a ferry flight could be 6500 km, giving her all the range she needed to cross oceans in a single flight.

Before dawn on December 16th, 1929, 500 soldiers of the British Army hauled R100 out for the first time. Most of her senior engineers, including Shute, were onboard for the inital flight to Cardigon. After making several slow circles of Howden to test the controls (Shute's worry about man-power and the rudder proved unfounded) the R100 set off for York. When she had been flying for awhile and it was clear everything was fine, everyone relaxed, and had breakfast - bacon and eggs, cooked in the galley. In the British airship service of the First World War, it was a proverb that you only got a rest while aloft - certainly R100's first test flight was a pretty relaxing affair, possibly the chilliest initial test flight in aviation history.

During this test flight, R100 flew over York before turning for Cardigton.

Docking at the mast at Cardington, R100 had shown only minor defects, which her engineering team immediately started fixing. The next day, R100's speed trials began, somewhat to the annoyance of Air Ministry officials. They were very polite about it, but they flat out didn't believe that flat out the R100 could do 130 km/h (81 mph.) This R100 in fact, did, 130 km/h that day. (The later Zeppelin Hindenberg was faster, but not by much.) Returning to the tower that night, a frost reduced visibility to the point that from 700 ft one could barely see the ground. This would have been a problem in a period airplane, but was no problem at all for the R100. She approached the docking mast at Cardington so slowly that the officers could actually consider the problem of docking, consult with each other, and then decide what to do, something you can't really do on final in an airplane. Shute says quick decisions were never made flying R100 - because it was not needed. Piloting R100 was as relaxing as being a passenger.

 At Christmas R100 was put into the hanger next to R101. As I imagine the Air Ministry couldn't think of a plausible reason to deny them, the engineering staff was allowed to visit the R101 under construction, and came away for the most part impressed. The level of craftsmanship on the framework particularly impressed Shute, which he thought rated higher than the R101's effort. He did notice, however, that R101 had a cable running from its propeller to its frame to spread out the force of the engine thrust. This was perfectly valid, and had been done on British airships and blimps in the first World War. Still, it struck Shute as odd. Considering the bleeding edge of high tech approach of the R101, couldn't they have figured out a better arrangement than that? It was like finding fixed landing gear on a jet fighter. At any rate, after years of work, the R100 staff was immensely pleased with their airship, and took a Christmas vacation with a good conscience.

What the R100 team didn't know about the R101, what had not been reported in the newspapers, was that R101's initial test flights had been less successful. Indeed, they had shown her engineers that R101 already had serious problems.

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

Part 2

Part 3

Part 4

Part 5