- Payne, Alan
- Naval technology
- None noted.
- RAN Ships
- None noted.
- June 1976 edition of the Naval Historical Review (all rights reserved)
The hull was assembled from a variety of girders prefabricated in spruce stiffened 3-ply which were fireproofed and varnished. The girders were mainly ten-inch equilateral triangles ten feet in length, with hardwood blocks in the end joints reinforced with steel gusset pieces. When assembled as part of the hull of the airship, each girder panel was braced with diagonal wires, and every ring with radial, diametral and chordal wires, all of which were piano wire correctly tensioned. The completed structure became a tremendous birdcage with about a hundred miles of piano wire to keep it in position; as the use of adjustable turnbuckles was prohibited because of weight, a great deal of patience and skill was required in setting up the wires. Payne found that considerable difficulty was experienced in doing this job correctly. In his opinion it was a defective wire joint that was responsible for the loss of R38; and when the Hindenburg was lost, her designer Herr Eckener considered that the same trouble had also caused her loss. It is perhaps odd to think that the Achilles Heel of the airship was not hydrogen, but the bracing-wires – although it must be admitted that the defective wires were responsible (through static) for the hydrogen catching fire.
R31 had 21 gasbags, which filled the bulk of the space of the hull. The bags were made up of two-ply cotton fabric, with rubber between the plies, and there was rubber on the inner face with one layer of gold-beaters’ skins (skins of oxen, as used by beaters of gold leaf) which was afterwards varnished. No alternative to the expensive gold-beaters’ skins was available during the War, although experiments were tried with substitutes.
R31 was driven by six 275 hp Rolls-Royce Eagle engines, and on her maiden flight she was slowly worked up to full power, and made a speed of 70 mph; a remarkable performance due partly to her streamlined form, which was the first to have the Control Room in the nose flush with the hull.
R31’s very brief career began with her maiden flight, in August 1918, under the command of Squadron-Commander W. C. Hicks, and only lasted a couple of hours. She was an easy ship to handle, and was very manoeuvrable. In fact, although much larger, she could carry out a complete turn in about half the time of the R23 Class. It was considered that she was overpowered, and consequently the two rear gondolas were removed and replaced by a single unit on the centreline. This only reduced the speed by 5 mph, and increased the lift.
The second flight took place on 16th October 1918, and was to be a momentous one. After various runs had been carried out to check the effects of the revised engine-arrangement, a short series of turning trials were done.
‘I climbed up to the top of the ship where we had a gun-platform,’ recorded Payne, ‘I remember feeling the absence of wind and noise, when suddenly a frightened face appeared at the top of the two-foot diameter tube with a rope-ladder in it, and Hicks’ First Lieutenant told me that the top of the vertical fin had collapsed – this explained why I felt that the nose of the ship was well up. Hicks had realised that the top vertical fin was acting as a king-post supporting the two horizontal fins, and it was the downward air pressure on the horizontal fins that proved too much for the girder in the vertical fin.’
Hicks immediately threw out water-ballast to keep the ship at roughly 15 degrees by the bow. This enables the air pressure at 40 knots to hold the horizontal fins in position, and so allowed the horizontal rudders to function. This accident happened near Cardington, and many people saw crewmen on top of the airship tearing away great areas of fabric that was fouling the operation of the rudders and elevators.
When the ship arrived back at the airfield and the engines were stopped, the horizontal fins naturally collapsed, due to the absence of air-pressure. All this was a frightening experience for those on board.
‘But we on board did not realise to the full what had happened. The ship’s fin-girders were subsequently strengthened, and while she had some minor troubles after this, there were none that were very serious.’ Actually defects did occur on her third flight.
R31’s third and final flight took place on 6th November 1918, with a full Service crew on board. The routine delivery flight to the airship base at East Fortune, near Edinburgh, should have taken six or seven hours at cruising speed. It is by no means certain what took place on this final flight, but it has been reported that some of the girders began to fail. It is obvious now that we will never know what really happened, although we do know that Hicks was an experienced officer, but a cautious one. In any event, he decided to land at Howden in Yorkshire, and so sealed R31’s death-warrant, after a total of only nine hours’ flying time.
After R31 landed, her crew was dispersed and a most remarkable and totally mysterious oblivion surrounds the first airship to be completed before the Armistice. It seems just possible that it was the utter chaos in airship policy generated by the end of the War that contributed to this shocking oblivion. In any case, R31 was left to rot in the worst possible place – in the hangar where only three months earlier had perished by fire R27 and three non-rigids. A damaged hangar on the bleak Yorkshire moors was the last place in the world for R31, a very lightly-built wooden structure. And so the beautiful streamlined wooden airship perished from neglect. Somebody was to blame, but it certainly was not her builders, Short Brothers, or her Admiralty designers. Muller, the expert on girder construction, could probably have repaired any damage in a couple of months.
The mystery remains, and can never be solved. In a sense, the whole thing is unique, as was the R31 design. The same sad fate did not befall the sister-ship R32, which was a complete success, had certain improvements, and was stronger. Eventually, due to the Government’s decision to scrap military airships in 1921, R32 did end up in the same graveyard at Howden, but she had redeemed R31’s undeserved shame and neglect.
The only clue to R31’s fate is provided by the airship authority Lord Ventry, who happened to be the adjutant at Howden at the time. He recalls that it was well into 1919 before anyone in authority began asking any questions about R31. One would think an airship to be rather a big object to lose. In due course, a Court of Inquiry was convened to examine the question of R31’s unserviceable condition. The Inquiry was a farce, as no member present knew why the airship was there.