Free Slide Rule by Nevil Shute

and the Airship Guarantee Company, a subsidiary of Vickers Ltd, employed three consultants who were to teach me the fundamentals of my job and carry out research into the methods. Professor Bairstow was our authority on aerodynamics, Professor Pippard on structures, and Mr. J.E. Temple was the most practical and useful of them all because he had been Chief Calculator for Wallis on the design of a former ship, the R.80, built by Vickers at the conclusion of the war. My job was to get together a staff of calculators to do the work on R.100, translating the theories of the consultants into the forces and stresses in each member of the ship and so providing the draughtsmen with the sizes for each girder and each wire.
    This was an important matter, for the previous experience of England in the construction of rigid airships had not been happy. Rigid airships had been built during thewar upon the lines of the German airships that had been shot down. Vickers had had a hand in this programme with the construction of R.80 and other ships, and R.80 at any rate had been properly stressed according to the best aerodynamic data available at the time. Most of the other ships had been designed and built by a staff of government officials attached to the Air Ministry, but the methods of the German designers were not known, of course, and these ships had been built empirically and by copying the sizes of the girders in the German ships. The last of them was R.38. On her third flight a structural weakness in the girders was revealed, but was made light of. On her fourth flight she was doing turning trials over the Humber in very perfect weather when she broke in two, the front part catching fire and falling in the river and the rear part coming down on land. Forty-four lives were lost in the accident. At the enquiry into the disaster it came out that the officials responsible had made no calculations whatsoever of the aerodynamic forces acting on the ship in flight; it was not therefore very surprising that she broke when doing turns at full helm and full speed.
    On taking up my new job I spent many hours in reading old reports and records to find out what had been done in the field of airship calculations before, and when I came on the report of the R.38 accident enquiry I sat stunned, unable to believe the words that I was reading. I had come from the hard commercial school of de Havillands where competence was the key to survival and a disaster might have meant the end of the company and unemployment for everyone concerned with it. It was inexpressibly shocking to me to find that before building the vast and costly structure of R.38 the civil servants concerned had made no attempt to calculate the aerodynamic forces acting on the ship, and I remember going to one of my chiefs with the report in my hand to ask him if this could possibly betrue. Not only did he confirm it but he pointed out that no one had been sacked over it, nor even suffered any censure. Indeed, he said, the same team of men had been entrusted with the construction of another airship, the R.101, which was to be built by the Air Ministry in competition with our own ship, the R.100.
    The situation in the airship world at that time was curious. It was generally agreed in 1924 that the aeroplane would never be a very suitable vehicle for carrying passengers across the oceans, and that airships would operate all the long-distance routes of the future. We were all quite wrong, of course, but at that time it seemed reasonable; no aeroplane had yet succeeded in crossing the Atlantic from east to west, whereas a German airship, the Graf Zeppelin, was already carrying commercial loads of passengers both ways to South America upon a regular schedule. In England Sir Dennis Burney was perhaps the leading airship enthusiast, acting with Vickers Ltd, and in 1923 this group put forward a proposal to the Government that they should build six commercial airships and set up a company to