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
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
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
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.
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.
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.
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.
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.