SS class airship

SS class airship

Company type	Military airship
Industry	Aviation, Military
Founded	1915
Headquarters	United Kingdom
Products	Non-rigid airships (blimps)

SS (standing for Submarine Scout or alternatively Sea Scout) class airships were straightforward, cost-effective, and rapidly deployable small non-rigid airships, commonly known as "blimps". They were developed urgently in response to the German U-boat menace threatening British maritime traffic during World War I. An additional role assigned to these airships was the identification and destruction of naval mines. The class demonstrated considerable adaptability and operational success, with a total production reaching 158 units across multiple variants.

Requirement

Following the onset of World War I, the escalating threat posed by German submarines to British shipping became increasingly evident, with significant losses recorded in October and November 1914. On 4 February 1915, the Imperial German Admiralty issued a declaration stating: "All waters surrounding Great Britain and Ireland are designated as a war zone. Beginning 18 February, any enemy merchant vessels located within this zone will be destroyed."

The situation had reached a critical point, prompting the Admiralty to acknowledge that airships could provide effective submarine detection and valuable fleet reconnaissance capabilities. At that time, Britain's airship resources were limited to only seven units—four operated by the RNAS (HMA 17, 18, 19, and 20), two continental models, and a single training craft from Willows. Furthermore, only four airfields featured hangars suitable for accommodating these airships. As a result, on 28 February, the First Sea Lord, Admiral Lord Fisher, convened a meeting with Commander E. A. D. Masterman, Officer Commanding the Naval Airship Section, alongside representatives from Vickers and the London-based company Airships Limited, to explore the development of a fleet of appropriate patrol airships, sometimes referred to as "scouts".

Design and development

The airship was intended to achieve speeds between 40–50 mph (64–80 km/h), accommodate a two-person crew, carry 160 lb (73 kg) of bombs, be equipped with wireless communication devices, hold enough fuel for eight hours of flight, and reach an altitude of 5,000 ft (1,500 m). Above all, the design emphasized simplicity to streamline manufacturing and facilitate crew training. This was critical as the new airships, classified as "Submarine Scout" or "Sea Scout" (SS) models, needed to be operational within weeks rather than over several months.

Prototype

The initial SS model was developed at RNAS Kingsnorth on the Hoo Peninsula. It essentially consisted of a B.E.2c fuselage and engine stripped of wings, tailfin, and elevators, suspended below a deflated envelope from the airship HMA No. 2 (Willows No. 4), which had been stored inactive at the Royal Aircraft Establishment (RAE), Farnborough Airfield. The prototype was ready for testing within two weeks of project approval, and on 18 March 1915, the first SS class airship was officially commissioned. The entire development process took under three weeks, prompting Admiral Fisher’s enthusiastic remark: "Now I must have forty!"

Wing-Commander N. F. Usborne, who led the Kingsnorth facility, also played a significant role in the airship’s design. His dedication was formally acknowledged with the statement: "Admiral Sueter wishes to express his deep appreciation for Commander Usborne’s tireless efforts and commitment to advancing the airship program. Working late into the night and early morning hours, his scientific expertise was instrumental in achieving their remarkable success."

In addition to this effort, two private companies—Armstrong Whitworth and Airships Ltd.—were invited to propose designs. This collaboration resulted in three distinct SS class blimp variants: the SS "B.E.2c," the SS "Armstrong Whitworth," and the SS "Maurice Farman," named due to its resemblance to a Farman aircraft body as designed by Airships Ltd.

Envelope

The prototype’s envelope held approximately 20,500 cu ft (580 m³) of hydrogen gas; however, production models featured a larger envelope with a volume of around 60,000 cu ft (1,700 m³) but retained a similar shape. This provided an average gross lift of 4,180 lb (1,900 kg), a net lift capacity of 1,434 lb (650 kg), and a disposable lift of 659 lb (299 kg) when fully fueled with two crew members aboard. All SS variants utilized comparable envelopes constructed from four layers: two layers of rubber-proofed fabric sandwiching a rubber membrane, plus an additional rubber coating on the inner gas-facing surface. The exterior was sealed with five layers of dope to ensure weather resistance and complete gas impermeability. The initial two coats consisted of "Delta dope," a flexible coating first applied in 1913 on the British Army’s semi-rigid airship Delta, followed by two layers of aluminium dope and a final aluminium varnish layer. To reinforce the envelope’s nose and prevent deformation caused by wind pressure, 24 canes radiated from its center beneath an aluminium cap.

Unlike the prototype which had a single ballonet, production envelopes incorporated two ballonets each with a volume of 6,375 cu ft (180.5 m³). These ballonets were inflated by air drawn from the propeller slipstream through a scoop connected via an angled aluminium tube beneath the envelope, then distributed through horizontal fabric ducts equipped with non-return fabric valves known as "crab-pots."

Planes

The initial configuration included four fins (or planes) with rudders arranged radially around the envelope: two horizontal stabilizers and two lower fins arranged in an inverted V-tail layout. In certain instances, the pair of lower fins was substituted by a single central fin featuring a larger rudder. All fins were uniform in dimensions and shape, constructed from spruce, aluminium, and steel tubing, reinforced with wire bracing, and covered with doped fabric.

SS B.E.2c

The production car closely resembled the prototype, utilizing a wingless B.E.2c fuselage that had various fittings removed and replaced with two ash skids instead of wheeled landing gear. At the front, it was powered by a 75 hp (56 kW) air-cooled Renault engine driving a four-bladed propeller measuring 9 ft (2.7 m) in diameter.

The pilot’s seat was positioned behind the observer, who also functioned as the wireless operator. A camera was installed onboard, and armament included bombs mounted in frames suspended near the center of the undercarriage, along with a Lewis Gun affixed to a post beside the pilot’s position. The bomb sight and release controls were externally mounted on the starboard side adjacent to the pilot’s station.

SS Maurice Farman

Initially designed by Airships Ltd., this model employed envelopes with volumes of 60,000 cu ft (1,700 m³), later increased to 70,000 cu ft (2,000 m³). It featured dual control setups for both pilot and observer/wireless operator, with occasional addition of a third seat for an engineer or passenger. Renault engines were typically installed at the rear of the car in a pusher configuration, although one unit successfully utilized a Rolls-Royce Hawk. While slightly slower than the SS B.E.2c, these cars offered more spacious and comfortable interiors.

SS Armstrong Whitworth

This variant incorporated the Armstrong Whitworth F.K. car and shared many characteristics with the B.E.2c model but utilized a single-skid landing gear equipped with buffers. To maintain adequate lift margins, it required a larger envelope of approximately 70,000 cubic feet. The powerplant was a water-cooled 100 hp (75 kW) Green engine arranged in a tractor configuration. Fuel was stored in two aluminium tanks suspended from the envelope within fabric slings, which reduced weight by about 100 lb (45 kg) compared to the internal tanks used on the B.E.2c.

Airship stations

File:Submarine Scout airship Q27563.jpg

An SS airship lands after a patrol, showing the large crew required for handling on the ground. Another SS airship can be seen in the air.

Simultaneously, several new airship bases were established alongside a dedicated training facility at Cranwell. The development of the rigid airship programme was progressing rapidly, and these initial stations were subsequently supplemented by additional sites, collectively forming a network encircling the UK’s coastline.

Production

The manufacturing process began at the Royal Aircraft Factory in Farnborough but was soon relocated to Kingsnorth. Shortly thereafter, production expanded to include Vickers’ facility at Barrow-in-Furness as well as the Naval Air Station at Wormwood Scrubs in London. Nevertheless, output at these sites was frequently disrupted due to aircraft orders limiting envelope availability.

Approximately 60 units spanning three variants of the SS class blimp were produced, each costing around £2,500 (equivalent to £Template:Inflation in Template:Inflation-year, adjusted for inflation).

Service history and legacy

In the last 15 months of World War I, SS-type airships completed over 10,000 patrol missions, accumulating nearly 1.5 million miles and more than 50,000 flight hours. They identified 49 U-boats during these operations, attacking 27 either from the air or via naval vessels. Only one ship under airship escort was lost to enemy action.

An SS B.E.2c set a British airship altitude record by reaching 10,300 ft (3,100 m) during summer 1916, while the unique Hawk-powered SS Maurice Farman once maintained an extended patrol lasting 18 hours and 20 minutes. Additionally, in that same summer, an Armstrong Whitworth model treated with black dope successfully conducted nocturnal missions over France, demonstrating airships’ operational value alongside ground forces.

The SS design evolved with custom-built gondolas leading to new variants such as the SSP (Pusher), SSZ (Zero), SST (Twin), and SSE (Experimental SST). The demand for these adaptable "Sea Scouts" was substantial, resulting in a total production of 158 units across all models and derivatives, some of which were procured by France, Italy, and the United States.

While SS class types were crucial for coastal surveillance under fair weather conditions due to their limited engine power and relatively compact size, operations further offshore and in adverse weather required more capable designs. This led to the development of three additional classes: the Coastal, the C*, and the North Sea classes. These featured larger envelopes and more powerful engines, accommodated bigger crews, and offered extended patrol endurance compared to their predecessors.

Operators

France

• French Air Force

Template:Country data Kingdom of Italy

• Italian Air Force

Japan

• In 1921, the Imperial Japanese Navy obtained an SS-3 from the Royal Navy. Shortly after its first flight in Japan, it detonated in a hangar at Yokosuka Naval Base in 1922. The IJN subsequently built a domestic copy in 1923, which completed a single flight from Yokosuka to Osaka and returned to Kasumigaura Air Field. Unfortunately, this replica exploded mid-flight in 1924, resulting in the loss of all crew members.

United Kingdom

• Royal Navy

United States

• United States Navy

Specifications (typical)

Comparative specifications

General characteristics	SS [BE]	SS [MF]	SS [AW]	SSP	SSZ	SST
Length	143 ft 5 in (43.71 m)	143 ft 5 in (43.71 m)	143 ft 5 in (43.71 m)	143 ft 5 in (43.71 m)	143 ft 5 in (43.71 m)	165 ft (50 m)
Diameter	27 ft 9 in (8.46 m)	30 / 32 ft	32 ft (9.8 m)	30 ft (9.1 m)	30 ft (9.1 m)	35 ft 6 in (10.82 m)
Height	43 ft 5 in (13.23 m)	43 ft 5 in (13.23 m)	43 ft 5 in (13.23 m)	43 ft 5 in (13.23 m)	46 ft (14 m)	49 ft (15 m)
Volume	60,000 cu ft (1,700 m3)	60 / 70,000 cu ft	70,000 cu ft (2,000 m3)	70,000 cu ft (2,000 m3)	70,000 cu ft (2,000 m3)	100,000 cu ft (2,800 m3)
'Ballonet '	12,750 cu ft (361 m3)	12,750 / 19,600 cu ft	19,600 cu ft (560 m3)	19,600 cu ft (560 m3)	19,600 cu ft (560 m3)	19,600 cu ft ()
'Gross lift'	1.85 t	2.2 t	2.2 t	2.2 t	2.2 t	3.1 t
'Disposable lift'	0.64 t	0.6 / ~0.8 t	0.7 t	0.7 t	0.6 t	1.0 t
'Car length'	Template:Convert 24 ft m abbr = on	Template:Convert 20 ft m abbr = on	Template:Convert 26 ft m abbr = on	Template:Convert 26 ft m abbr = on	Template:Convert 17 ft 6 in m abbr = on	Template:Convert 17 ft 6 in m abbr = on
'Engine type'	Renault	Renault	Green Engine Co: Green engine	Rolls-Royce Hawk/Green	Rolls-Royce	Rolls-Royce/Sunbeam-Coatalen engines
'Engine power'	70 /75 hp	75 hp	100 hp	75 /100 hp	75 hp	75 /100 hp
'Fuel capacity'	60 gal	64 gal	90 gal	120 gal	120 gal	120 gal
Performance
'Maximum speed'	50 /52 mph	40 mph (64 km/h)	45 mph (72 km/h)	52 mph (84 km/h)	53 mph (85 km/h)	57 mph (92 km/h)
'Endurance (full speed)'	7–8 hours	7–8 hours	12 hours	12 hours	17 hours	17 hours
'Endurance (half speed)'	14–16 hours	14–16 hours	24 hours	24 hours
'Rate of climb'	700 ft/min	790 ft/min	500 ft/min	500 ft/min	1,200 ft/min	1,200 ft/min

_{Notes: · [BE] B.E.2c car · [MF] Farman car · [AW] Armstrong Whitworth car}

References

Notes

Bibliography

External links

• Information on SS class airships from the Airship Heritage Trust
• Details on Commander N. F. Usborne’s role in the SS class airship’s development
• Archival news footage showing an SS Class airship during launch and flight
• Oral history interview with Chief Petty Officer J S Middleton, who recounts building the prototype SS class airship in Reel 3/4