Slide Rule

Home > Fiction > Slide Rule > Page 10
Slide Rule Page 10

by Nevil Shute


  It was then a few days before Christmas. I had been working at high pressure for some time and enjoying it; now the first part of the flight trials had been completed and we had nothing much to worry about. I arranged the programme of work that was to be done on the ship, rang up Burney to get leave, rang up someone to enquire a good place to go to in Switzerland, and was ski-ing at Murren before Christmas. I think in many ways that was the best holiday I have ever had in my life because I came to it with a sense of achievement, of a difficult job well done; moreover for the first time in my life I had plenty of money at my disposal. I don’t think it lasted longer than a fortnight because I had to get back to my job, and wanted to, but that fortnight was a good one.

  Back at Howden the big shed seemed very empty without the ship. Practically all the men in the shops had been laid off, of course, but Burney had fixed up a design contract for a future airship from the Air Ministry with which to keep the experienced design staff in being till the flight trials were completed and the future programme for airships could be decided by Parliament. By that time, in January 1930, the depression in the United States was in full swing and its impact was becoming felt in England. It was becoming clear that two competing airship design staffs would not be kept in being through the hard times that were in sight; if more airships were ordered either Cardington would build them or we would. The decision which staff would be chosen to carry on largely depended on the performance of the two airships; the designers of the less successful ship would very soon find themselves looking for another job. This was an important factor in the later flight trials of the two ships, and in the ultimate tragedy. Urged by the instinct for survival both parties forced the flight trials ahead quicker than they should have gone, intent on proving that their own ship was the better. It was my good fortune that we had the better ship.

  The work on R.100 was finished about January 10th 1930; she was then ready for further flight trials and we stayed waiting for a calm to bring her out of the shed. Not much notice can be given of a dead calm, and so it was not particularly discourteous that I received a telephone call from Cardington at four o’clock in the afternoon on January 17th to tell me that the ship would be brought out at dawn next day and would fly immediately. Cardington is about a hundred and fifty miles from Howden and that day was my birthday; I had arranged a small party of friends from the flying club at a hotel in Leeds. Remarking that there was time, Master Drake, to finish our game of bowls, I arranged with the calculator who was coming down with me for the flight that he should meet me in Leeds at eleven o’clock and we would drive down to Cardington through the night.

  One does those things when one is young. I had reckoned without a freezing fog all down the Great North Road. I had a pretty little Singer coupé at that time, an advanced car for its day, but like others at that date it had no fog lights and no heating. Even parking lights reflected from the fog and made driving impossible, but with no lights at all we could see the sides of the road and could keep up about twenty miles an hour. Very soon the windscreen iced up, but it was designed to open, and we drove along like that. Ice formed on everything. It was nearly an inch thick on the inside of the roof above our heads; it coated our overcoats and formed in a great mass on the steering wheel between my hands; it was a tough drive. We got out every hour or so and stamped about to get the circulation back, and once or twice we found a coffee stall, in Stamford or in Grantham. By five o’clock in the morning we were within thirty miles of Cardington and we could still use no lights, and now we began to meet cyclists on the road, farm hands perhaps, going to milk the cows. We very nearly hit one a couple of times, and each time suffered a hair-raising skid upon the icy road as I braked heavily. I gave up then and parked by the roadside; better to miss the ship than to stand trial for manslaughter. An hour later the dawn came and we could see a little better, and got going again. We drove in to the air station at eight o’clock and to my delight the ship was only just leaving the shed; the same fog had prevented the R.A.F. handling party from getting to the aerodrome at the appointed time. We scrambled on board, and had breakfast as the ship rose up in to the air.

  All that day we flew above the fog and clouds, in bright sunshine. We suspended a variety of air speed indicators on cables below the ship and worked her up to her full speed, which as I have said was eighty-one miles an hour. We had several of the Cardington officials on board during this flight, who took this result with long faces. We all tried to get them to disclose what the full speed of R.101 was but they turned stuffy and wouldn’t tell us; the subject was evidently an awkward one and we had to abandon it.

  The value of a full power trial lies in the effect it has in disclosing weaknesses in the outer cover of the ship. In the case of R.100 the outer cover took up a curious wavelike formation when the ship was at full speed, which was not evident at cruising speed. These harmonic deflections ran longitudinally down the ship from bow to stern; they did not move at all. I climbed all over the ship with the riggers between the gasbags and the outer cover while the ship was at full speed to examine the attachments of the cover to its wiring system but I could find no place where the attachments were unduly stressed. Finally we came to the conclusion that the matter was of no importance, and was probably due to large-scale eddies of the air that passed over the hull.

  The outer cover was a weakness in both R.100 and R.101. In each ship the policy had been adopted of building with relatively few longitudinal girders compared with previous ships in order that the forces in the girders might be calculated more accurately, and this decision was undoubtedly influenced by the disaster to R.38. A ship with few longitudinals, however, must of necessity have larger unsupported panels of outer cover fabric than a ship with many. In both ships the outer cover was the main weakness. Extended flight trials were to prove that our outer cover on R.100 was just good enough for the service demanded of it, but only just.

  R.100 made another flight about January 22nd to investigate the curious deformations of the outer cover at full speed; we flew to Farnborough, where an aircraft from the experimental station came up and flew alongside us to photograph the cover while I was crawling about inside the hull with the riggers. At cruising speed, about seventy miles an hour, the cover was quite normal. The officials at Cardington grumbled a bit about it, inferring that we were selling them a bad airship, but they had no leg to stand on technically and it was decided to let the matter go. So far as I remember, Burney clinched the matter by pointing out that our contract only called for a top speed of seventy miles an hour; if they wished we would put a stop on the throttles of the engines to prevent the ship from going faster than that, which would make the cover quite all right.

  The contract for R.100 called for a final acceptance trial of 48 hours’ duration, and a demonstration flight to India. This latter flight was changed to a demonstration flight to Canada when the decision was taken to equip R.100 with petrol engines, because it was thought that a flight to the tropics with petrol on board would be too hazardous. It is curious after over twenty years to recall how afraid everyone was of petrol in those days, because since then aeroplanes with petrol engines have done innumerable hours of flying in the tropics, and they don’t burst into flames on every flight. I think the truth is that everyone was diesel-minded in those days; it seemed as if the diesel engine for aeroplanes was only just around the corner, with the promise of great fuel economy. It was decided amicably, therefore, that R.101 would make the flight to India since she had diesel engines, and we would fly to Canada instead.

  The final acceptance trial of R.100 lasted for fifty-four hours; it was an easy and effortless performance bearing out the old saying of the R.N.A.S. that the only way to get a rest in the airship business is to take the thing into the air and fly it. We left Cardington on the morning of January the 27th with twenty-two tons of fuel on board to burn before coming down, and we landed again on the afternoon of the 29th having lived very comfortably in the meantime. The weat
her from the start was vile. At Cardington it was misty with a moderate wind and signs of rain; we came down to seven hundred feet over Oxford but saw nothing of the ground. We never flew lower than about seven hundred feet in R.100 and seldom so low as that; our normal flying height was between fifteen hundred and two thousand feet. We passed on to Bristol in very bad weather, cruising at fifty-five miles an hour on three engines.

  By the middle of the afternoon we were on the south coast of Cornwall in a wind of over fifty miles an hour; we put on a fourth engine to bring the speed up to sixty-five, being unwilling to increase speed more until we saw how the ship behaved in the rough weather. She answered her controls well, but in this wind she took a long, slow pitching motion of about five degrees each way. This very slow pitching was the only motion that she ever took in bad weather except once in the vicinity of Quebec when she rolled a little in a patch of violently disturbed air. Nobody could ever have been sick in that ship.

  By dusk we were at the Channel Islands and heading up Channel to spend the night out over the North Sea. The ship had quite comfortable little two-berth cabins for fifty passengers, and we who had no routine duties went to bed at a normal time. At two o’clock in the morning I woke up, and becoming aware of my responsibilities I went down to the control car. I found them changing watch. On enquiring where we were, I was told that we were passing over Lowestoft. I asked what we had come there for, and I was told that since the wife of Steff, third officer, came from Lowestoft we had come as a graceful compliment to empty our sewage tank over the town. Steff was killed in R.101; I do not think that he would mind if I recall our ribaldry that night. The ship was then thrown into a turmoil because somebody had drunk the captain’s cocoa; I’m not sure it wasn’t me. Seeing that she was in good hands and not falling to bits, I went back to bed.

  I was up again at dawn, to find us crossing the coast at Cromer on our way to London in increasing fog. As we got near the city the normal white fog changed to thick, black, greasy stuff that left great streaks of oily soot upon the outer cover; it wreathed apart once and disclosed the Tower Bridge immediately below us; then it closed down thick and black. We saw nothing more till that evening after tea, when we picked up the lights of a fishing fleet in Tor Bay.

  At about eight o’clock, in the darkness, we went out to the Eddystone and using the lighthouse as a centre we did comprehensive turning trials on port and starboard helm for nearly an hour, calculating the radius of the turns by timing ourselves on a complete circuit and getting the circumference of the circle from the air speed. I have often wondered what the lighthouse keepers thought to see the lights of an apparently demented airship going round and round their lonely rock in the dark night.

  All night we cruised the Channel. We went up as far as Portland, and out into the Atlantic to the Scillies. At dawn when I came down to the control car we were cruising over Cornwall; in the rising sun the valleys were all filled with mist as if it had been poured out of a bottle, and this mist was white and gold and pink in the clear light, very beautiful. That morning we went up the Bristol Channel at an easy speed; near Bristol we ran into cloud and rain again. We landed to the mast at Cardington in the middle of the afternoon, with the ship very wet but none the worse for her long flight.

  I think it was during this flight that I went outside on top of the ship for the first time. R.100 had a little cockpit on top at the extreme bow, forward of the first gasbag and reached by a ladder in the bow compartment; this was for taking navigational sights with a sextant. From this cockpit a walking way ran aft on top of the ship along one of the girders; this was a plywood plank a foot in width with the outer cover stretched over it. To give courage to the inexperienced it had a rope lashed down along it every two feet or so, to serve as a handhold. This walking way ran the whole length of the ship to the rear of the fins, where another hatch was provided behind the last gasbag. The slope of the hull at the bow cockpit was about forty-five degrees, which made the first part a little tricky to climb, and personally I always went from bow to stern because the rush of air pushed you up the first climb and you didn’t have to look down. When the ship was cruising at about sixty miles an hour, as soon as you got to the top, or horizontal, part of the hull you were in calm air crawling on your hands and knees; if you knelt up you felt a breeze on your head and shoulders. If you stood up the wind was strong. It was pleasant up there sitting by the fins on a fine sunny day and whenever I went up there I would usually find two or three men sitting by the fins and gossiping. We kept a watch up there in daylight hours to keep an eye on the outer cover, and the riggers got so used to it that they would walk upright along this little catwalk with their hands in their pockets, leaning against the wind and stepping over my recumbent body as I crawled on hands and knees. Burney lost his wrist watch up there one evening; it lay on top of the ship all night and was found by one of the riggers at dawn next day, and returned to him.

  This was one of the features of an airship which distinguished it from an aeroplane. You could climb all over every part of it in flight and carry out any repairs or maintenance that might be necessary. If the wind hampered the work you reduced speed. We did not care to run R.100 slower than about twenty miles an hour because some elevator control was necessary to keep the ship at a given height without continually valving gas or jettisoning ballast, but that speed was sufficiently low to permit the most extensive repairs, as we were to find later.

  After this flight the ship was put back into her shed for a considerable time. We formally handed her over to the Air Ministry, which means that we gave her to our competitors at Cardington, her English trials being satisfactorily concluded. They proceeded to make a number of modifications to her in preparation for the Atlantic flight. She did not fly again till some time in May, when we made a flight of twenty-four hours’ duration in her, cruising over Lancashire and Yorkshire. In this flight the light tail fairing of the hull, the last ten feet, well aft of the gasbags and the fins, suffered damage due to a high aerodynamic pressure. Wind tunnel tests on the model had shown suction forces over most of the hull aft of Frame 3 at all angles of inclination, but at the extreme tail of the model a pressure had been shown. By the time this was appreciated the tests were over, the model had been dismantled and the wind tunnel was working upon other matters; we discussed this one isolated point of high pressure with the aerodynamic specialists. Nobody, with the knowledge we possessed at that time, could explain theoretically why there should be pressure there, so we assumed it was a false reading due to some experimental error. But it wasn’t, and this little empty framework of light girders collapsed. The Cardington designers, who were now in charge of R.100, solved the problem by cutting off the offending pointed tail and modifying her stern to a bluff, rounded shape not unlike the cruiser stern of a ship. This had the advantage of shortening the ship by fifteen feet without much detrimental effect, but it cannot be said that it improved her looks.

  This modification kept R.100 in her shed for a month or so, and in the meantime R.101 came out to the mooring mast for further trials. It had been realised before Christmas that the small disposable load of R.101 would make a flight to India impossible because she couldn’t carry enough fuel, and a programme had been put in hand to try to put her right. All unnecessary equipment, including the useless servo motors, was taken out of her, her gasbag wiring was let out to increase her gas volume, and—last resort of desperate engineers—she was to be parted in the middle and an extra parallel portion inserted in her length, containing an extra gasbag. These alterations finally brought her disposable load up to 49.3 tons, still five tons less than that of R.100. In fairness, however, it must be realised that her diesel engines used less fuel than ours, so that in the end there might not have been much to choose between the ships in regard to range and load-carrying capacity.

  It was impossible to insert the extra bay in R.101 at once, and when she came out to the mast for further trials in June the ship had been gutted of all superf
luous equipment and the gasbags had been let out. Immediately she was put on to the mast, in a very light wind, the outer cover split longitudinally, making a tear a hundred and forty feet long. The wind was rising so she could not be put back in the shed, and the riggers mended it at the mast. A second, shorter split occurred next day, and was mended. They reinforced the cover with tapes stuck on inside with dope, and made a short test flight. They then made two more flights in daylight on consecutive days, each lasting for about twelve hours; these were less for technical reasons than to show the ship at the rehearsal for the R.A.F. display at Hendon, and at the display itself. Publicity was important to them. They did no full power trial, probably because they were afraid of the outer cover.

 

‹ Prev