H.M.Balloon Factory SS (Sea-Scout)

Utilised by the RNAS during WW 1 for anti-submarine patrol and convoy escort duties. Hurriedly conceived as a composite of the Willows JV (HMA No. 4) airship and a car formed from the fuselage of an RAF B. E. 2c aircraft, the resultant combination was a simple non-rigid that could be used for submarine hunting and convoy protection. It was first tested in March 1915 and given the designation ‘SS’ class, indicating ‘Sea Scout’ or ‘Submarine Scout’. Alternative cars could be fitted, and although the greater number used the B.E.2c fuselage (these being SS1 to SS3, SS8 to SS10A, SS12 to SS20, and SS23 to SS25), 11 were fitted with Armstrong Whitworth cars and 12 with Maurice Farman cars. Some are on record as going to France and Italy, while they also inspired certain US vessels of similar construction.

The original ‘SS’class airships flew with a dorsal fin, while the ventral one of SS40 was extended in area. Anticipated work was agent-dropping, but it was actually used for night reconnaissance.

The ‘SS’ class was used for patrols over the Dover Straits and Irish Narrows, the first base to have the type being that established at Capel near Folkestone on 8 May 1915; a second base began operations with the ‘SS’ on 6 July of the same year, this being at Polegate (Eastbourne) where there were three, compared with five at Capel.

In later models the gas capacity was increased first to 1699 cu.m (60,000 cu ft) and later to 1982 cu.m (70,000 cu ft) from the original 580.5 cu.m (20,500 cu ft).

The SSO had a capacity of 70,500 cu ft., were 43.58m long and 9.14m in diameter. Useful lift was calculated to be 609.62kg. The class was powered by the 75hp Rolls-Royce Hawk six cylinder engine with a maximum forward speed of 42 kts. On patrol speed was 30 kts.

Other more radical variations were introduced to produce the ‘SST’ class, which had twin engines but of which only six were constructed, and the ‘SSP’ class (the last letter indicating pusher propulsion) that was even less successful, only two being built.

As might be expected these airships, which gave to the English language the word ‘Blimp, had the capability to stay aloft for many hours, the normal flight duration being seven hours although records exist claiming up to twice this figure. The type served throughout the war on the same duties and certainly had a deterrent effect on submarine commanders, whose vessels it was possible to see below the surface of the water. Some, with Armstrong Whitworth F. K. 3 fuselages doing duty as their cars, were po-wered with 74.6-kW (100-hp) Green water-cooled motors as an alternative to the standard powerplant, the Hawk engine being particularly associated with the Maurice Farman nacelles. Production was about 150 ‘SS’ class airships.

The final variant of the ‘32’ class airship was the ‘SSZ’ class (Z indicating the ultimate or zero form), of which no less than 93 were ordered although only 63 of these went to the Royal Navy: SSZ23 and SSZ24 were sent to the United States where the latter became A5472, while SSZ21 and SSZ22 went to France.

The type was introduced late in 1916 and although the engine was usually the Rolls-Royce Hawk, two were fitted with the Renault V-S of similar rating, and all were used for similar work to that performed by the earlier ‘55’ type. The main visual difference between the two classes was the specially designed car that took the place of the aeroplane fuselages used formerly. In fact the SSZ was not originally intended for sea patrol, being designed to be towed by surface vessels of the Belgian coast patrol and by monitors, when their role would have been no more than aerial platforms for gunnery spotting after release and under their own power. The very first airship of this type was in fact built at Capel (Folkestone) and later flown to the Dunkirk area, where it was based at St Pol on 21 September 1916, three months after it had been constructed.

Perhaps the chief claim to history enjoyed by the SSZ is the fact that, despite being of non-rigid construc-tion and therefore capable of being flown only if the weather was suitable, they were responsible for spotting 49 submarines, of which 27 were claimed as sunk. To do this it was necessary for the airships to remain aloft for lengthy periods and the record for this goes to the crew of SSZ39, who remained in the air during the summer of 1918 for a continuous period of 50 hours. This was more than double that of the accepted ‘long patrol’, which was in the region of 24 hours, although the average was 12.

A crew of three manned the airships. The crew car was designed to float like a boat and water landings were made on numerous occasions. In the front sat the wireless/telegraphist, the pilot in the centre and the engineer in the rearward position. Directional control was by rudder behind the vertical fin on the underside of the ship and elevators on the horizontal fins. To maintain envelope pressure and compensate for gas loss two ballonets were filled with air from a scoop immediately aft of the pusher propeller. The two ballonets were equivalent to about one third of the envelope volume which was a two ply rubberised fabric.

Patrol duration was listed at 12 hours at full speed although at half speed patrols of 23 to 30 hours were quite common. In 1918 a flight of 50 hours 55 minutes was logged. It must be also remembered that the overhaul life of an aero engine at this time seldom exceeded 20 hours and was quite often as little as five hours.
A total of seventy-one of the Submarine Scout class were built between 1916 and 1918.

‘SS’ class
Powerplant: one 55.9-kW (75-hp) Renault V-S or Rolls-Royce Hawk six- cylinder water-cooled piston , or one 74.6-kW (100-hp) Green water-cooled piston 
Maximum speed 48 kph (30 mph) with Renault or Rolls-Royce engine, or 80 km/h (50 mph) with Green engine.
Useful lift 3001 kg (6,615 lb)
Diameter 9.75 m (32 ft 0 in)
Length 43.59 m (143 ft 0 in)
Volume 1982.2 cu.m (70,000 cu ft)
Armament: one 7.7-mm (0.303-in) Lewis machine-gun, plus bombs.

‘SSO’ class
Engine: 1 x Rolls-Royce Hawk 6 cyl, 75 hp.  

‘SSZ’ class
Type: sea patrol airship.
Powerplant: one 55.9-kW (75-hp) Rolls-Royce Hawk six-cylinder or Renault V-8 water-cooled piston engine.
Maximum speed 77 kph (48 mph)
Service ceiling 2400 m (7,875 ft)
Normal endurance 12 hours
Useful lift 3300 kg (7,275 lb
Diameter 9.75 m (32 ft 0 in)
Length 43.59 m(143 ft 0 in)
Volume 1982.2 cu.m (70,000 cu ft)
Armament: one 7.7-mm (0.303-in) Lewis gun for the observer, plus bombs