NS class blimp
The British NS (North Sea) class blimps were the largest and last in a succession of non-rigid airship
A blimp, or non-rigid airship, is a floating airship without an internal supporting framework or keel. A non-rigid airship differs from a semi-rigid airship and a rigid airship in that it does not have any rigid structure, neither a complete framework nor a partial keel, to help the airbag...

 designs that served with the Royal Naval Air Service
Royal Naval Air Service
The Royal Naval Air Service or RNAS was the air arm of the Royal Navy until near the end of the First World War, when it merged with the British Army's Royal Flying Corps to form a new service , the Royal Air Force...

 during World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

; developed from experiences gained with earlier classes to operate off the east coast of Britain on long-range patrols. Despite early problems, examples of the class went on to break all flying records for non-rigid airships, and the type became regarded as the most efficient of its kind.


The NS class airship was developed in response to the increasing requirement of the RNAS to carry out long-range anti-submarine patrols and convoy escort duties off the west coast of Great Britain, and was so-called as the type was intended to work in collaboration with the Grand Fleet which mainly operated in the North Sea
North Sea
In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively...


In 1916, Britain's rigid airship
Rigid airship
A rigid airship is a type of airship in which the envelope retained its shape by the use of an internal structural framework rather than by being forced into shape by the pressure of the lifting gas within the envelope as used in blimps and semi-rigid airships.Rigid airships were produced and...

 programme was unable to provide an effective airship; the NS class was developed as a substitute using experiences gained with the Coastal
Coastal class blimp
The Coastal Class were a class of blimp used by the Royal Naval Air Service during World War I. The C class blimp operated by the United States Navy after the war was a completely unrelated design. In total 35 Coastals were built, all at RNAS Kingsnorth, Kent...

 and improved C*
C-Star class blimp
-References:* London, P. U-Boat Hunters: Cornwall's Air War 1916-19 Dyllansow Truran, Truro. ISBN 1-85022-136-9-External links:*...

 classes to create a larger and more weather-worthy long-endurance non-rigid vessel. The main requirements for the new design were as follows:
  • Capability to carry out flights of considerable duration [24 hours with a speed of 55 –].
  • Great reliability.
  • The necessary lift to carry an ample supply of fuel.
  • Adequate arrangements to accommodate a double crew in comfort.

Approval was given in January 1916 for the construction of six NS class airships; designed and built at RNAS Kingsnorth
RNAS Kingsnorth
RNAS Kingsnorth was a First World War Royal Navy air station for seaplanes and airships, mainly operating as an experimental and training station, but also providing anti-submarine patrols...

 on the Hoo Peninsula
Hoo Peninsula
The Hoo Peninsula is a peninsula in England separating the estuaries of the rivers Thames and Medway. It is dominated by a line of sand and clay hills, surrounded by an extensive area of marshland composed of alluvial silt. The name Hoo is the Old English word for spur of land.-History:The Romans...

, not far from the naval dockyard
Chatham Dockyard
Chatham Dockyard, located on the River Medway and of which two-thirds is in Gillingham and one third in Chatham, Kent, England, came into existence at the time when, following the Reformation, relations with the Catholic countries of Europe had worsened, leading to a requirement for additional...

 at Chatham.


Similar to the Coastal
Coastal class blimp
The Coastal Class were a class of blimp used by the Royal Naval Air Service during World War I. The C class blimp operated by the United States Navy after the war was a completely unrelated design. In total 35 Coastals were built, all at RNAS Kingsnorth, Kent...

 and C-Star classes
C-Star class blimp
-References:* London, P. U-Boat Hunters: Cornwall's Air War 1916-19 Dyllansow Truran, Truro. ISBN 1-85022-136-9-External links:*...

, the "North Seas" employed a tri-lobe envelope based on the Astra-Torres
Astra-Torres airship
The Astra-Torres airships were non-rigid airships built by Société Astra to a design by Spaniard Leonardo Torres Quevedo in France between about 1908 and 1922. They had a highly-characteristic tri-lobed cross-section rather than the more usual circular cross-section. This was the result of moving...

 design principles. It incorporated all the improvements that had been previously suggested for those classes – its shape was streamlined throughout, and having a capacity of 360000 ft3 it was significantly larger than that of the "Coastals". Six ballonet
A Ballonet is a air-filled flexible container that is located inside the envelope of a non-rigid or semi-rigid airship. Such an airship can have one or more ballonets, commonly one fore and one aft...

s of 128000 ft3 in total were provided; equivalent to 35.5% of the total volume.

Attached to the envelope were four fins. The smaller top fin was merely for stabilizing purposes; while the larger other three were identical in size and shape, and carried the rudder
A rudder is a device used to steer a ship, boat, submarine, hovercraft, aircraft or other conveyance that moves through a medium . On an aircraft the rudder is used primarily to counter adverse yaw and p-factor and is not the primary control used to turn the airplane...

 and elevator
Elevator (aircraft)
Elevators are flight control surfaces, usually at the rear of an aircraft, which control the aircraft's orientation by changing the pitch of the aircraft, and so also the angle of attack of the wing. In simplified terms, they make the aircraft nose-up or nose-down...

s. The aluminium
Aluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances....

 fuel tanks were initially situated above the top ridges of the envelope, but its varying shape caused the aluminium fuel lines to fracture and consequently the tanks were later placed inside the envelope.


The first examples of the type were equipped with two enclosed cars slung from the underside of the envelope – a control car, and to the rear an engineers' car (power or engine car), joined by an exposed wooden walk-way suspended on cables.

The control car was rectangular in cross-section, measuring 35 ft (10.7 m) long and 6 ft (1.8 m) high, and was constructed from a frame of light-steel tubing braced with diagonal wires. The forward portion was clad in duralumin
Duralumin is the trade name of one of the earliest types of age-hardenable aluminium alloys. The main alloying constituents are copper, manganese, and magnesium. A commonly used modern equivalent of this alloy type is AA2024, which contains 4.4% copper, 1.5% magnesium, 0.6% manganese and 93.5%...

, and the remainder covered with fabric laced to the framework. Duralumin sheeting was chosen instead of aluminium as, unlike aluminium, it is not affected by the action of sea air and water. Windows and portholes provided both light for the crew, and afforded a good field of view.

The forward section of the control car was extensively glazed, and formed the pilot's cabin which housed all the flight controls, navigating instruments, engine-telegraphs and voice pipes. Behind this was the wireless telegraphy cabin, while the living and sleeping accommodation for the 10-man crew was located at the rear of the car. In addition to the radio equipment, the wireless operators' compartment carried Aldis lamp
Signal lamp
A signal lamp is a visual signaling device for optical communication . Modern signal lamps are a focused lamp which can produce a pulse of light...

s as well as international maritime signal flags
International maritime signal flags
The system of international maritime signal flags is one system of flag signals representing individual letters of the alphabet in signals to or from ships...

. The latter could be lowered from the control car, and were effective for communicating with foreign vessels.

The engineers' car housed the controls for the engines, and gave access to a flanged hotplate for cooking that was attached to one of the engine exhaust pipes. Two dynamos
Dynamos may mean:*The plural of dynamoAn association football club:*Dynamos F.C., a South African association football club*Dynamos F.C., a Zimbabwean association football club*Lusaka Dynamos F.C., a Zambian association football club...

 and batteries provided power for the ship's electrical systems which included lights, telephones and signalling lamps etc.


The type was initially fitted with a pair of 250 hp Rolls-Royce Eagle engines mounted one either side of the power car in streamlined enclosures. Each drove a 9 ft (2.7 m) diameter four-bladed propeller on independent shafts through an elaborate transmission system.


A maximum of six 230 lb (104.3 kg) bombs could be carried as well as up to five machine-guns. Similar to the Coastal and C-Star class airships, one gun was mounted on a platform on top of the envelope, and was reached through a climbing shaft.


The normal crew comprised two watches of five – necessary for extended patrols – and consisted of a Captain and Second Officer, a Coxswain
The coxswain is the person in charge of a boat, particularly its navigation and steering. The etymology of the word gives us a literal meaning of "boat servant" since it comes from cox, a coxboat or other small vessel kept aboard a ship, and swain, which can be rendered as boy, in authority. ...

 and Second coxswain, two W/T Operators, two Engineers and two Air Gunners. The Captain was in overall command of the vessel, and was assisted by the Second Officer in navigating, maintaining height, and regulating gas pressure. The Coxswain was responsible for the rest of the crew, and for the care and maintenance of the ship whilst on the ground. He or the Second Coxswain steered the vessel in flight from a position at the very front of the control car. During patrols, the Air Gunners took on the duties of look-outs and also acted as cooks.

Testing and problems

The first example, N.S.1, carried out initial flight trials on 1 February 1917. Preliminary trials were regarded as being satisfactory; the ship achieving a speed of 50 mph (80.5 km/h) and proving easy to handle. Two further flights were carried out in March, the second of which was a longer cross-country round trip from Kingsnorth to Maidenhead
Maidenhead is a town and unparished area within the Royal Borough of Windsor and Maidenhead, in Berkshire, England. It lies on the River Thames and is situated west of Charing Cross in London.-History:...

, Farnborough
Farnborough, Hampshire
-History:Name changes: Ferneberga ; Farnburghe, Farenberg ; Farnborowe, Fremborough, Fameborough .Tower Hill, Cove: There is substantial evidence...

, Guildford
Guildford is the county town of Surrey. England, as well as the seat for the borough of Guildford and the administrative headquarters of the South East England region...

, and back to Kingsnorth again. Following the success of this flight, N.S.1 transferred to RNAS Pulham
RNAS Pulham
RNAS Pulham was an Royal Navy Air Service airship station, south of Norwich, UK. Though land was purchased by the Navy in 1912 the site was not operational until 1915...

, Norfolk
Norfolk is a low-lying county in the East of England. It has borders with Lincolnshire to the west, Cambridgeshire to the west and southwest and Suffolk to the south. Its northern and eastern boundaries are the North Sea coast and to the north-west the county is bordered by The Wash. The county...

, on 18 April 1917 for more extensive trials. Minor snags encountered during flights over the next few weeks were ironed out, and it was then decided to carry out a full-scale endurance test taking place on 5 June. However, just over 16 hours into the flight, the universal joint
Universal joint
A universal joint, universal coupling, U joint, Cardan joint, Hardy-Spicer joint, or Hooke's joint is a joint or coupling in a rigid rod that allows the rod to 'bend' in any direction, and is commonly used in shafts that transmit rotary motion...

 on one of the propeller driveshafts broke and the ship returned to Pulham. Then, on 26 June, she again took to the air at 06:00 and remained aloft until 07:22 on 28 June – a flight duration of during which she covered 1536 miles (2,471.9 km) and encountered only minor technical problems. At that time, this was a record for a British airship of any type.

N.S.2s early trials at Kingsnorth were also satisfactory, but during an endurance trial on 27 June similar to that of N.S.1, she became unmanageable when she lost gas and was wrecked in an attempted landing near Stowmarket
-See also:* Stowmarket Town F.C.* Stowmarket High School-External links:* * * * *...

, Suffolk
Suffolk is a non-metropolitan county of historic origin in East Anglia, England. It has borders with Norfolk to the north, Cambridgeshire to the west and Essex to the south. The North Sea lies to the east...


N.S.3 made an 11-hour non-stop flight on 22 July 1917 to her operational base at RNAS East Fortune
East Fortune
East Fortune is a village in East Lothian, Scotland, located 2 miles north west of East Linton. The area is known for its airfield which was constructed in 1915 to help protect Britain from attack by German Zeppelin airships during the First World War. The RNAS airship station also included an...

 following trials in June at Kingsnorth. She was joined there on 6 September by
N.S.1, and by N.S.4 from Kingsnorth on 15 October. N.S.5 set off for East Fortune on 12 December, but both engines failed within sight of her destination, and she drifted with the wind for about 10 miles (16.1 km) before they could be restarted. However, since both engines continued to be troublesome it was decided to make a "free balloon" landing, but she was damaged beyond repair during the attempt.


The Roll-Royce engines together with their method of installation and complex transmission continually presented problems. They were connected to the propellers via long, heavy driveshafts that were only lightly supported, thus placing undue strain on the transmission system and invariably causing the universal joint nearest the propeller to fracture.

The Kingsnorth design team hastily set about redesigning the power car and transmission gear, and at the same time, staff at East Fortune were also looking into ways of improving the design. Kingsnorth considered the idea of replacing the Roll-Royce engines with 240 hp Fiat
FIAT, an acronym for Fabbrica Italiana Automobili Torino , is an Italian automobile manufacturer, engine manufacturer, financial, and industrial group based in Turin in the Italian region of Piedmont. Fiat was founded in 1899 by a group of investors including Giovanni Agnelli...

 units having a direct drive to the propellers; while East Fortune's Engineering Officer, Lt.Cdr. A. S. Abell, RNVR
Royal Naval Reserve
The Royal Naval Reserve is the volunteer reserve force of the Royal Navy in the United Kingdom. The present Royal Naval Reserve was formed in 1958 by merging the original Royal Naval Reserve and the Royal Naval Volunteer Reserve , a reserve of civilian volunteers founded in 1903...

, together with Flt.Cdr. J. S. Wheelwright, DSC
Distinguished Service Cross (United Kingdom)
The Distinguished Service Cross is the third level military decoration awarded to officers, and other ranks, of the British Armed Forces, Royal Fleet Auxiliary and British Merchant Navy and formerly also to officers of other Commonwealth countries.The DSC, which may be awarded posthumously, is...

 (Captain of N.S.3), came up with the idea of raising the control car to the same level as the engineers' car; form them into a single fully enclosed unit that measured 85 ft (25.9 m) in length and tapered to the stern, and fit the propellers directly onto the engine crankshafts. These and other minor measures provided the crew with more room and improved their comfort; increased top speed through reduced air resistance (the redesigned car was more aerodynamic and positioned closer to the envelope); caused a reduction in weight; and improved reliability due to the abolition of the troublesome transmission shafts. In January 1918, the Admiralty
The Admiralty was formerly the authority in the Kingdom of England, and later in the United Kingdom, responsible for the command of the Royal Navy...

 granted permission for these modifications to be undertaken at both Kingsnorth, and at East Fortune where the work was completed by the beginning of March.

Mainly due to the lack of a suitable alternative, official interest continued in the NS class despite the early reliability problems and the loss of two examples during their first months of service, and a further six were subsequently ordered in November 1917. Production continued until the end of the war and for a short time after.


The following from

Under the continuing command of Captain Wheelwright and with Admiralty officials on board,
N.S.3 successfully completed test flights on 11 March 1918, and the following day she undertook an eight-hour trial whilst maintaining a speed in excess of 60 mph (96.6 km/h). Subsequently, numerous requests to start operational duties were submitted to the Admiralty, and on 3 April permission was granted for a three-quarters power duration flight over land. N.S.3 flew from Longside to Kingsnorth and back to East Fortune; a journey of 816 miles (1,313.2 km) in 22 hours which at the time constituted a record for British airships. During the flight both engines ran perfectly – the starboard engine ran continuously, while the other was only stopped for about five minutes to replace a broken dynamo drive-belt.

On 17 April
N.S.3 performed her first convoy escort, and from 20–22 April she completed a flight of 55 hours with various convoys – the longest flight to that date of any non-rigid airship.

During May 1918, she flew over 130 hours – one patrol lasted for 33 hours, and another for 20 hours which was curtailed only by orders to return to base due to increasing winds.

During a flight on the night of 31 May / 1 June whilst participating in the testing of the anti-aircraft capabilities of the Grand Fleet and shore batteries near Rosyth
Rosyth is a town located on the Firth of Forth, three miles south of the centre of Dunfermline. According to an estimate taken in 2008, the town has a population of 12,790....

, N.S.3 achieved a height of 10000 ft (3,048 m) – another record for the type.

In early June 1918, she commenced towing trials with the destroyer HMS
V and W class destroyer
The V and W class was an amalgam of six similar classes of destroyer built for the Royal Navy under the War Emergency Programme of the First World War and generally treated as one class...

 to examine the possibility of towing an airship at speed should it break down or run short of fuel. The tests were initially successful reaching speeds of almost 20 knots (39.2 km/h), but on the final run
N.S.3 touched down on the sea.

N.S.3s final patrol commenced on 21 June 1918 with orders to proceed from East Fortune to escort a south-bound Scandinavian convoy. She joined the convoy off Aberdeen
Aberdeen is Scotland's third most populous city, one of Scotland's 32 local government council areas and the United Kingdom's 25th most populous city, with an official population estimate of ....

 around 7 pm; however, later that night increasing winds prompted the decision to return to base at full speed, but severe turbulence and loss of gas caused the ship to crash into the sea early on with the loss of five lives. The survivors were picked up from the floating wreckage some time later by the destroyer HMS Moy
River class destroyer
The River-class destroyer was a heterogeneous class of torpedo boat destroyer built to assorted builders' designs for the Royal Navy at the turn of the 20th century, which saw extensive service in World War I...


Other history

In its modified form the type contributed much valuable war service, and at the Armistice
Armistice with Germany (Compiègne)
The armistice between the Allies and Germany was an agreement that ended the fighting in the First World War. It was signed in a railway carriage in Compiègne Forest on 11 November 1918 and marked a victory for the Allies and a complete defeat for Germany, although not technically a surrender...

 on 11 November 1918 six examples were still in service at operational stations – N.S.7 and 8 were based at East Fortune and escorted the surrendered German fleet back to Rosyth, while N.S.4, 6, 11 and 12 operated from Longside. Two further ships, N.S.14 and 16, were under construction at Kingsnorth, and were flown after the war.

Under the command of Captain W. K. Warnford N.S.11 set an early endurance record of , and accompanied by N.S.12 made the first airship journey to Norway. N.S.11 then went on to set a further flight endurance record of 101 hours during a mine
Naval mine
A naval mine is a self-contained explosive device placed in water to destroy surface ships or submarines. Unlike depth charges, mines are deposited and left to wait until they are triggered by the approach of, or contact with, an enemy vessel...

-hunting patrol on 9–13 February 1919 having covered some 4000 miles (6,437.4 km). Rigid airship R34 then broke this record when she completed a voyage from East Fortune to Mineola
Mineola, New York
Mineola is a village in Nassau County, New York, USA. The population was 18,799 at the 2010 census. The name is derived from a Native American word meaning a "pleasant place"....

, Long Island
Long Island
Long Island is an island located in the southeast part of the U.S. state of New York, just east of Manhattan. Stretching northeast into the Atlantic Ocean, Long Island contains four counties, two of which are boroughs of New York City , and two of which are mainly suburban...

, United States in 108 hours, and while subsequently attempting (unofficially) to regain this record N.S.11 was lost. In the early hours of 15 July on what was officially supposed to be a mine-hunting patrol, she was seen to fly beneath a long "greasy black cloud" off Cley next the Sea
Cley next the Sea
Cley next the Sea is a village on the River Glaven in Norfolk, England, 4 miles north-west of Holt and east of Blakeney. The main A149 coast road runs through the centre of the village, causing congestion in the summer months due to the tight, narrow streets. It lies within the Norfolk Coast AONB...

 on the Norfolk coast and a massive explosion was heard shortly after. A vivid glare lasted for a few minutes as the burning airship descended, and finally plunged into the sea after a second explosion. There were no survivors, and the findings of the official Court of Enquiry were inconclusive, but amongst other possibilities it was thought that a lightning strike may have caused the explosion.

Following the loss of N.S.11, only N.S.7 and 8 remained in service – N.S.14 had been sold to the US Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

 and the rest had either been wrecked, deleted or deflated. N.S.8 was deleted in October 1919, while the final flight of the last of the type, N.S.7, took place on 25 October 1921.

In total 14 examples of NS class blimp were constructed. The extended endurance flights and records broken were simply the result of normal operational flying routine while escorting convoys, hunting for submarines and performing other duties with the Fleet, and due to their success in modified form they were regarded as being probably the best large non-rigid airship that had been produced by any country.


  • Royal Navy
    Royal Navy
    The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

  • United States Navy
    United States Navy
    The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...


  • Ballonets: [×6] 128,000 ft³ (3,600 m³)

See also

External links

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