North Sea or N.S. airship was originally designed to act as a
substitute for the Rigid airships, which, in 1916, was still a
long way from being available for work of practical utility. From
experience gained at this time with airships of the Coastal type
it was thought possible to construct a large Non-Rigid capable
of carrying out flights of twenty-four hours' duration, with a
speed of 55 to 60 knots, with sufficient accommodation for a double
main requirements fall under four headings:
Capability to carry out flights of considerable duration.
The necessary lift to carry an ample supply of fuel.
Adequate arrangements to accommodate the crew in comfort.
these could be fulfilled the authorities were satisfied that ships
possessing these qualifications would be of value to the Fleet
and would prove efficient substitutes until rigid airships were
available. The North Sea, as may be gathered from its name, was
intended to operate on the east coasts of these islands.
Developement was undetaken at the Kingsnorth Airship Station on
the north Kent coast, in the river Thames estruary and was the
largest non-rigid designed in Britain up to that time. There was
at first some discussion as to whether the the Astra Torres or
the Parseval type of envelope would be the better, but the principles
behind the design of the latter, were not fully understood in
this country. Copies could be and had been made,, but any enlargements
or modificatrions would require a re-design of the trajectory
rigging bands which were a feature on the German airship. This
was a dangerous undertaking and, so the Astra Torres pattern which
had been adapted without trouble for the Coastal ships, was again
form used for the new design was not only larger than bvefore,
but more streamlined, looking quite similar in outline to the
first ship, when completed and put through her trials, was voted
a success, and the others building were rapidly pushed on with.
When several were finished and experience had been gained, after
long flights had been carried out, the North Sea airship suffered
a partial eclipse and people were inclined to reconsider their
favourable opinion. Thus it was that for many months the North
Sea airship was decidedly unpopular, and it was quite a common
matter to hear her described as a complete failure. The main cause
of the prejudice was the unsatisfactory design of the propelling
machinery, which it will be see,, later was modified altogether,
and coupled with other improvements turned a ship of doubtful
value into one that can only be commended.
envelope is of 360,000 cubic feet capacity, and is designed on
the Astra-Torres principle for the same reasons as held good in
the cases of the Coastal and C Star. All the improvements which
had been suggested by the ships of that class were incorporated
in the new design, which was of streamline shape throughout, and
looked at in elevation resembled in shape that of the S.S. airship.
Six ballonets are fitted, of which the total capacity is 128,000
cubic feet, equivalent to 35.5 per cent of the total volume. They
are fitted with crabpots and non-return valves in the usual manner.
rigging is of the Astra-Torres system, and in no way differs from
that explained in the previous chapter. Nine fans of the internal
rigging support the main suspensions of the car, while similar
fans both fore and aft provide attachment for the handling guys.
Auxiliary fans on the same principle support the petrol tanks
and ballast bag.
- Four gas and six air valves in all are fitted, all of which
- Two ripping panels are embodied in the top lobe of the envelope.
N.S. ship carries four fins, to three of which are attached the
elevator and rudder flaps. The fourth, the top fin, is merely
for stabilizing purposes, the other three being identical in design,
and are fitted with the ordinary system of wiring and kingposts
to prevent warping.
petrol was originally carried in aluminium tanks disposed above
the top ridges of the envelope, but this system was abandoned
owing to the aluminium supply pipes becoming fractured as the
envelope changed shape at different pressures. They were then
placed inside the envelope, and this rearrangement has given every
the envelope of the N.S. is rigged a long covered-in car. The
framework of this is built up of light steel tubes, the rectangular
transverse frames of which are connected by longitudinal tubes,
the whole structure being braced by diagonal wires. The car, which
tapers towards the stern, has a length of 85 feet, with a height
of 6 feet. The forward portion is covered with duralumin sheeting,
and the remainder with fabric laced to the framework. Windows
and portholes afford the crew both light and space to see all
that is required. In the forward portion of the car are disposed
all the controls and navigating instruments, together with engine-telegraphs
and voice pipes. Aft is the wireless telegraphy cabin and sleeping
accommodation for the crew.
complete electrical installation is carried of two dynamos and
batteries for lights, signalling lamps, telephones, etc. The engines
are mounted in a power unit structure separate from the car and
reached by a wooden gangway supported by wire cables. This structure
consists of two V-shaped frameworks connected by a central frame
and by an under-structure to which floats are attached. The mechanics'
compartment is built upon the central frame, and the engine controls
are operated from this cabin.
the original power units two 250 horse-power Rolls Royce engines
were fitted, driving propellers on independent shafts through
an elaborate system of transmission. This proved to be a great
source of weakness, as continual trouble was experienced with
this method, and a fracture sooner or later occurred at the universal
joint nearest to the propeller. When the modified form of ship
was built the whole system of transmission was changed, and the
propellers were fitted directly on to the engine crankshafts.
a later date 240 horse-power Fiat engines were installed, and
the engineers' cabin was modified and an auxiliary blower was
fitted to supply air to the ballonets for use if the engines are
the N.S. ship as modified the car has been raised to the same
level as the engineers' cabin, and all excrescences on the envelope
were placed inside. This, added to the improvement effected by
the abolition of the transmission shafts, increased the reliability
and speed of the ship, and also caused a reduction in weight.
leading dimensions of the ship are as follows: length, 262 feet;
width, 56 feet 9 inches; height, 69 feet 3 inches. The gross lift
is 24,300 lb.; the disposable lift, without crew, petrol, oil,
and ballast, 8,500 lb. The normal crew carried when on patrol
is ten, which includes officers.
in the case of the Coastal, a gun is mounted on the top of the
envelope, which is approached by a similar climbing shaft, and
guns and bombs are carried on the car.
ships have become notorious for breaking all flying records for
non-rigid airships. Even the first ship of the class, despite
the unsatisfactory power units, so long ago as in the summer of
1917 completed a flight of 49 hours 22 minutes, which at the time
was the record flight of any British airship. Since that date
numerous flights of quite unprecedented duration have been achieved,
one of 61 1/2 hours being particularly noteworthy, and those of
upwards of 30 hours have become quite commonplace.
the Armistice one of these ships completed the unparalleled total
of 101 hours, which at that date was the world's record flight,
and afforded considerable evidence as to the utility of the non-rigid
type for overseas patrol, and even opens up the possibility of
employing ships of similar or slightly greater dimensions for
6 appeared several times over London in the summer months of 1918,
and one could not help being struck by the ease with which she
was steered and her power to remain almost stationary over such
a small area as Trafalgar Square for a quite considerable period.
flights referred to above were not in any way stunt performances
to pile up a handsome aggregate of hours, but were the ordinary
flying routine of the station to which the ships were attached,
and most of the hours were spent in escorting convoys and hunting
for submarines. In addition to these duties, manoeuvres were carried
out on occasions with the Fleet or units thereof.
the foregoing observations it must be manifest that this type
of ship, in its present modified state, is a signal success, and
is probably the best large non-rigid airship that has been produced
in any country.
ships departed from the use of aeroplane technology for the gondolas
and their own design and layout was created. There were two main
one for the engine, and one for the Command Cabin. These were
often joined together by a small walkway slung below the tri-lobe
envelope. The enclosed control cabins enabled the airships to
have a longer endurance as it gave the crews some comfort, with
sleeping quarters and cooking facilities. The kitchen
cooking facilities were heated by the exhaust gasses, piped through
from the engines.
of the most famous NS class ships were NS7 & NS8. Both of these
ships were based at Rosyth in Scotland and at the end of the war,
they escorted the surrendered German fleet back to Rosyth.
The US - North Sea Ship
One North Sea Class ship was destined for use in America. The Aircraft
Record card is for NS 14, built at Kingsnorth in late 1918 with
Wheelwright modified cars.
She made flying trials on 14 December, 1918, and was then deflated
and shipped to the USA. Her subsequent history is a bit hazy but
this is what we have researched:
Packed up and shipped to America for US Navy, 22 April, 1919.
Given Navy Bureau serial number A5580.
Sent to Wingfoot Lake N A S, Suffield, Ohio, for evaluation.Arrived
on 17 May. Not inflated.On 13 December, transferred to Hampton Roads,
Arrived on 30 January, 1920.
Subsequent US Navy history unknown.
Turned over to US Army 22 September, 1925.
Stricken from the Navy List 28 January, 1926.
So far no records have come to light to determine whether this ship
was ever inflated and flown in the United States. We would be interested
to know if NS 14 was ever flown in the US.