Deciding
to dispense with normal construction techniques, the designers
of the Royal Corps of Naval Constructors along with a prominent
designer Herr Muller who had defected from the Schutte-Lanz
airship factory, began construction of the new 31 Class
ships. The influence of Muller and the Shutte-Lanz ships became
apparent, as both of the new ships were to be made of wood.
The
R31 was the first to be completed at the new factory at Cardington.
The Government had loaned Shorts the sum of £110,000 towards
the construction of a 700ft double bay airship shed. The Cardington
project had been singled out for special attention as Shorts Brothers
had been kept clear of the 23 Class projects and had been designated
the new 30s serial numbers.
The
R31 made a break in the design of the previous ships in that her,
and the R32 were the first rigid airships the British produced
without swiveling propellers. However moving away from traditions
designs, the control cabin had dispensed with the gondola being
held underneath the body of the ship, instead it was fitted well
forward, flush under the hull. This gave the crew much easier
access to a walkway along the keel inside the ship, to the tail.
The
ship was composed of reinforced spruce plywood girders, varnished
and fireproofed. Each one was 10 inches equilateral triangles
by 10ft long. Every girder was braced with diagonal wiring and
every ring with a diametrical and cordial wires, all of them solid
piano wires, tensioned upon assembly.The 21 gasbags constructed
of rubberized cotton lined with goldbeaters' skins. There was
an internal corridor which at the bow, contained the control car
with it's navigating and W/T, and officers and bunking compartments..
The amidships engines were fitted with reversing gears. Each engine
had an electric starting motor and generator which supplied power
for a complete lighting system and for an internal telephone service.
Cooling the engines was in the form of shuttering on the engine
cars. Unlike the German ships, parachutes were provided for the
crew, and another comfort was provided in the form of hot food,
as the rations could be heated and cooked on exhaust-gas heated
stoves.
For
defense of the ship, a metal ladder from the control car lead
to machine gun positions on the top of the hull, with more gun
positions under her tail cone, in gondolas, and along the walkway.
The Chief of Naval Ordinance agreed that the ship would carry
a 12-pounder semi automatic cannon for use against U-boats. This
would be mounted in a special car 20 feet aft of the control car,
along with the ship's other fitments of anti-aeroplane machine
guns. A bomb load was decided as two 520 pound bombs and four
230 pound bombs. Unfortunately the turn of events with the war
ensure that these would never be fitted to the R31.
The R31 was half as large again in volume compared to the R23X
class ships, and a disposable lift of some 16.5 tons compared
again to the 23X class of 9 tons. This was seen as a large jump
in British design techniques and innovations. The only problem
which came out of the initial test flights was the lack of automatic
petrol pumps, and hence when the ship was in the air, the fuel
had to be manually pumped to keep the ship in trim. The service
and main tanks were designed to be "slipped" overboard
in case of emergency.
The
R 31 made her first trial flight in July 1918 around Bedford under
the command of Squadron Commander W.C.Hinks for 2 hours. The first
trial saw that she surpassed all expectations as she reached an
impressive top speed of 70mph. The design expectations were to
be an improvement on the 50-55mph on the 23X class but the design
team were very surprised at the actual speed attained. She was
faster than any other airship flying. Powered by six 275 hp Rolls
Royce Eagle engines, she was a true greyhound. On
this flight it was also noted that a rare phenomenon occurred
in the behavior of the wooden structure, which flexed to an extent
sufficient for two men, posted at opposite ends of the keel, to
lose site of each other during turns.
During her initial trial it was found that the R 31s fuel
consumption was unexpectedly high, and it was therefore decided
to remove one of the six engines. However, surprisingly this resulted
in a reduction in speed of only some 5mph, yet saved considerable
weight.
On
her second trial flight on October 16th 1918, the R31 returned
to Cardington with her upper fin and rudder laid flat over to
the starboard side along the afterbody It appears that her wire-braced
fins and rudders were shorter and more effective that that of
previous ships, and were probably insufficiently stressed. An
eyewitness account by Stephen Payne, an Admiralty Observer recorded
his account on the flight as follows :-
"I
had climbed up to the top of the Ship where we had a gun platform.
I remembered feeling the absence of wind and notice, when suddenly
a frightened face appeared on the top of the two foot diameter
tube with a rope ladder in it, and Hinks' First Lieutenant told
me that the top vertical fin had collapsed - this explained why
I felt t hat the nose of the ship was well up. Hinks had realized
that the top vertical fin was acting as a kingpost supporting
the two horizontal fins and it was the downward air passage on
the horizontal fins that proved too much for the girder in the
vertical fin. Hinks immediately dropped ballast to trim the ship
15 degrees at he bow. This enabled the air pressure at 40 knots
to hold the horizontal fins in position, and so it allowed the
horizontal rudders to function. The accident happened near Cardington
and many people saw crewmen on top of the airship tearing away
great areas of fabric fouling the operation of the rudders and
elevators. When the ship arrived back at Cardington the engines
were stopped, the horizontal fins naturally collapsed, due to
the absence of air pressure".
The
ship was taken back in to the shed and the simple repairs completed.
It was agreed that modifications would be made to the tail assembly,
the dimensions having been been too great and the controls too
powerful. One other modification was the amputation of the tail
cone and the sitting gun post with a wide arc of fire at that
point, superior to that of the German Zeppelins of the time.
The
airship was finally commissioned on 6th November 1918 having logged
a total of 4 hours in her flying trials. She left Cardington for
her new home of East Fortune in Scotland where she was to join
the R29. On the journey up the country she flew in to a torrential
storm and it was noticed that her some of her girders were beginning
to show signs of failure, possibly due to her earlier flying with
oversensitive controls. Squadron Leader Hincks as therefore decided
to abort the deliver and that the ship would dock in to Howden
in Yorkshire for repairs. The R31 landed safely at Howden and
was put in the large double shed which had recently suffered fire
damage when the R27 had burnt in the shed. The roof repairs had
not been totally completed, and temporary repairs were made the
roof, and so the ship was moved in to a shed in poor condition
to hold her. The crew were sent to Edinburgh to continue to East
Fortune where they were commissioned to and return to the ship
at a late date, and fly her back up to East Fortune.
Some 5 days later, on November 11th 1918 the end of the War was
signaled. The decisions on the whole wartime airship programme
would then have to be reevaluated. A decision was reached to leave
the R31 in the shed until further resources and decision could
be made for her future. Unfortunately the roof leaked and the
water permeated in to the ship and joints. This caused the the
gelatin glue which held the wooden girders together to deteriorate.
Early in the New Year of 1919 a Court of Inquiry was held to determine
who was responsible for her being out of condition. Unfortunately
nobody could be found, and Lord Ventry even commented that no
one knew why exactly she was still at Howden. The Admiralty later
discussed the status of the ships and it was deemed that the R31
was beyond the state of economical repair. In February 1919 she
was deleted and dismantling commenced.
Even
though she was an innovative design and concept for the new class,
the first ship out of the new Cardington Factory only had a life
of 4 hours flying trials and 4 hours 55 minutes commissioned.
A total of life of some 8 hours 55 minutes. With hindsight and
had the war continued enough for the R31 to be reconditioned,
it is agreed that the R31 would have provided the Grand Fleet
with a suitable scouting airship capable of accompanying the Fleet
during it's sweeps and fast enough to have a reasonable chance
if engaged against the Zeppelins.
No
smoke without fire
The
R 31 was sold for scrap to a coal merchant for £ 200.
The merchant though he make a profit selling the remains
as firewood, but following complaints by his customers,
he discovered that the wood would not light as it had been
treated with a fireproofing chemical.