.

R.29 differed from its predecessors in that minor modifications to the shape of the hull had given them slightly more gas capacity, but more important was the elimination of the external keel corridor. The function of this feature was primarily to distribute the weight of fuel tanks, ballast bags and similar items, and only secondarily to strengthen the hull, so its absence in the two 23X ships was intended to effect a considerable saving of weight without causing any significant loss of strength and also to improve manoeuvrability. The various loads were concentrated at the bulkheads and suspended from the radial wiring which maintained the hull in its correct polygonal shape.

Compare the 23 Class with the 23X Class.

An internal corridor which allowed the crew to travel between the cars was formed by inverted U-shaped ribs positioned above the two lowest longitudinal girders, the surrounding gasbags being appropriately shaped. The corridor also gave access to the ballast bags and petrol tanks. The latter were interconnected by a long, wide aluminium tube running underneath them, an arrangement which helped with refuelling and could be used in an emergency to jettison fuel.

Checkout the film of the R29

The four engines were again Rolls Royce Eagle V12 designs, but they were the later Series 6 models, which produced 300 hp at full revolutions. The engine arrangement was the same as that used originally for the 23 class ships, with pairs of swivelling propellers in the forward and after gondolas and twin engines driving fixed propellers in the midship car. The radical and original decision to do without a normal keel was fully vindicated when the first trials were held.

Not only were the two airships able to turn more quickly than their forerunners, but the real benefit was found when the lift and trim tests were held; the disposable lift was more than 8 1/2 tons, much better than any previous British airship and allowing a more effective bomb load to be carried as well as sufficient fuel for extended cruising. One handicap common to both ships, as well as to their predecessors, was the absorbent nature of the hull's outer covering of doped linen; a few hours of rain could add around a ton of water to the weight.

R.29 was a more fortunate craft than it's sister ship the R 27, in every way and the most successful wartime rigid, being the only one to meet enemy action. She was commissioned on 20th June 1918, based at East Fortune and in a brief operational career of less than five months flew 335 hours and covered an estimated 8,215 miles.

Once she carried out a patrol of over 30 hours, twice more she made a flight longer than 20 hours and three times she encountered German U-boats. The first escaped, the second ran on to a mine and only the last was attacked.

On Sunday 29th September, at about half past one in the afternoon and in exceptionally calm conditions, R.29, captained by Major G. M. Thomas, was escorting a convoy bound for Scandinavia when a faint patch of oil was seen discolouring the water near Newbiggin Point. A message, "Oil patch rising below me," was signaled by Aldis lamp to HMS Ouse, one of the escorting destroyers, which turned at once to help. Her captain could not see the slight evidence that was apparent to the airmen high overhead and he signalled for more information, "Drop light over it." In reply the airship indicated the probable whereabouts of the submarine by dropping not a flare but a 230 lb bomb, the destroyer joining in the attack with two depth charges as the first explosion subsided.

Then R.29 dropped a second bomb and a calcium flare to mark the position of the oil patch, at which point another destroyer, HMS Star, joined with Ouse and two armed trawlers to add more depth charges to the barrage. At half past two, HMS Star reported considerable quantities of oil rising to the surface. destroyers then steamed off after the convoy.

A buoy was placed as a marker by one of the trawlers and a deep depth charge was dropped, while R.29 remained on watch for more than an hour. When she at last left to rejoin the convoy at four o'clock large amounts of oil were still bubbling to the surface. It was subsequently confirmed from intelligence reports that UB.115 had been destroyed in the attack.

It was the sole success recorded by any British wartime rigid.

After the Armistice R.29 flew another 16 hours before May 1919, when her midship car was replaced by a smaller and lighter type containing only one engine driving a single propeller. In this modified form she flew a further 87 hours, including a flight in June over Edinburgh, Berwick, May Island and the Firth of Forth, when she was accompanied by R.34.

She was finally deleted in October, 1919, having covered an estimated 11,334 miles in service, more than any other British rigid up to that time.