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R 26

Following the success of HMA No. 9, further ships were ordered by the Admiralty. Along with the Vickers Company, three new contractors were required to produce rigid ships. The Vickers Company had already proven themselves with the design and construction of No. 9 and were the only company with any experience of building a large ship.

Statistics:
Length 535ft
Diameter 53ft
Speed 52mph
Engines 4 x 250hp
Volume 942, 000cft

 

Following the trials and design success of HMA No. 9, it was agreed that the Zeppelin threat had to be tackled head on; the Admiralty required more ships. There were initial problems at the Admiralty with regards to change of staff and also general opinion regarding rigid airships, as the successful non-rigid programme was expanding rapidly. However in June of 1915, along with the Vickers Company, three new contractors were selected to produce rigid ships.

The three new contractors were Beardmore, Armstrong and Whitworth and finally Shorts Brothers. All three companies were to become famous in the world of aviation. By October 1915 the drawings were approved and three ships were ordered. By December the pace of design and the requirement for big ships had increased dramatically and a further sixteen ships had been budgeted for by the Admiralty. All of these ships were to become known as the 23 Class, which were in effect stretched versions of the original No. 9. The designs were seen in essence as modified versions of No.9, with an extra bay inserted in the middle of the ship. A gun platform was added to the top of the ship designed to take a two pound gun and two Lewis machine guns. The platform was surrounded by 18 inch sanctions carrying lifelines. These sanctions could be extended to double the height in order to carry a canvas windscreen. Three other Lewis guns were to be fitted at the extreme tail, in the control car further aft and on the top walking way.

The bomb load was to be greater than that of HMA 9 but none was actually specified. The ships each possessed an external keel, to the same pattern as the No. 9. The cabin being 45 feet long contain crew accommodation, a wireless room and a bomb room. From the keel further aft were three gondolas which were suspended below and accessible by open ladders.

The ship gondolas also contained airtight buoyancy bags in case the ships had to alight on water. This was a technical requirement of all ships since HMA 1 - the Mayfly. With this rapid expansion of the requirement for airship production, there were a few problems in that so far, only one company had actually built a ship and hence had all the facilities.

In April 1916 the Government approved for a total fleet of 10, 23 class ships, but this was later modified in the light of further design technology available from Germany. The later ships becoming the R23X class and the R31 class.

The HMA 23 was the first to be completed, and hence the designation of the class of ships. There were a number of delays in the initial constructions and the ship was completed on 26th August 1917. This led to the order of the R26 as Vickers had the space available to build the ship. On lift and trim trials, the HMA 23 was found to have a disposable lift of only 5.7 tons due to the machinery being two tons heavier than originally estimated. Five weeks later the HMA 25 was completed and her tests gave almost identical results. Although not unexpected, the figures were disappointing and 2 weeks later on the 18th October the Admiralty decided that the design must be altered. On the day of the decision the HMA 24 was also tested and found to be mysteriously two thirds of a ton heavier than her sister ships, with a lift of only 5.1 tons. The alterations to the ships included the removal of dynamos and bomb frames and many other items which were deemed not necessary were removed.

The Admiralty ordered that modifications be carried out at once to R.26, which was still in the early stages of construction, while the other three ships were to be modified similarly but, of necessity, over a longer period and slightly less drastically. The measures to be undertaken were aimed at lightening the airships by the elimination of all unnecessary weight. In addition to removal of the dynamos, buffer wheels and bomb frames, many other small items not considered essential were either taken out or replaced with lighter equipment. The folding tables which had been intended for the keel cabin were never installed and the original plan of fitting a two-pounder gun on the top platform was also discarded. The rear car was replaced by a smaller and lighter one containing an engine with direct drive to a single two-bladed propeller 13 feet 6 inches in diameter. As there was now no space for the auxiliary controls, these were transferred to the keel cabin.

Some of these modifications had already been carried out on the first three ships, while others followed in due course. Together they effected a marked, if not substantial, improvement to the airships' performance.

R.26, on which Vickers could not begin work until No 9 had left Barrow, arrived much later. All the recommended modifications were incorporated in the course of her construction. Although built more quickly than the others, in only about a year, she did not fly until March 1918.

The last of the class was R.26. (The Admiralty decided on 18th December 1917, that all future rigid airships should have the prefix R before their number.) Apparently the only one of her class to incorporate all the design changes, she was commissioned on 22nd April 1918, and stationed at Howden. During tests she was found to have a disposable lift of 6 1/4 tons, a top speed of 54 mph and a ceiling of 3,500 feet. It was also discovered that if the engines were stopped at 53 mph the speed fell to 18 mph in two minutes, so great was the drag. By the end of the year she had flown 191 hours and 29 minutes, of which the highlights were a flight with No 23 over London on 25th October and a patrol of 40 hours 40 minutes on 4th/5th June, when she was commanded by Major T . This was the longest flight yet by a British rigid, beating No 23's previous record, set up a few days earlier, by 32 minutes. Later in the year she was transferred to Pulham and, commanded by Major Watt, she supervised the surrender of German submarines at Harwich on 20th November 1918.

In January 1919, R.26 flew a further 6 hours 18 minutes, and then had her bows specially strengthened before being experimentally moored out in the open, using the "three wire system". She had a tendency to assume a tail up attitude, But this was overcome by fastening sandbags to the after guys, and she survived for over a week without harm. Then the weather worsened, rain soaked her envelope and a snowstorm finally beat her into the ground. Her cars were removed, allowing her to float again, but it was soon found that the damage she had sustained was too severe for repairs to be worthwhile. On 24th February the order was given for her to be scrapped and her official deletion followed on 10th March.


 

Related ships: HMA 1, HMA 9, HMA 23 X

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