SSZ class
General information
Type	Patrol airship
National origin	United Kingdom
Primary user	Royal Navy
Number built	77
History
First flight	1916

The SSZ (Sea Scout Zero) non-rigid airships or "blimps" were developed in United Kingdom during World War I from the earlier SS ("Sea Scout") class. The main role of these craft was to escort convoys and scout or search for German U-boats. A secondary purpose was to detect and destroy mines.^[1]

The SSZ was built at the Royal Naval Air Service (RNAS) airship station at Capel-le-Ferne^[2] near Folkestone to the design of three officers that were serving there^[3] as a successor to the SS class.^[4]

Similar to other SS class types, the SSZs had an envelope of 70,000 cu ft (2,000 m³) capacity containing two ballonets of 6,375 cu ft (180.5 m³) each;^[5] and like the SSPs, the fuel was contained in aluminium tanks slung on the axis of the envelope.^[6]

The design of the car was a departure from that of other SS types. It was streamlined, boat-shaped and watertight, was floored from end-to-end, and was enclosed with sides of fabric-covered 8-ply wood^[3] or aluminium. The car was comfortable and accommodated a 3-man crew – the forward position being occupied by the wireless operator/gunner with the pilot seated amidships, and the engineer was stationed at the rear.^[6]

A single water-cooled 75 hp (56 kW) Rolls-Royce Hawk engine was mounted on bearers above the level of the rear of the car, and drove a 9 ft (2.7 m) diameter four-bladed propeller in pusher configuration.^[6]

The SSZ design was judged superior to the SSP, which had been developed at RNAS Kingsnorth at the same time, and so the SSP was cancelled.^[4]

The SSZ's patrolled extensively from late 1917 to late 1918. The average patrol lasted eight hours, but there were instances of flights of much greater duration – three of 25–26 hours; one of 30 h 20 min; and a record of 50 h 55 min held by SSZ.39 in the summer of 1918.^[6] After the Armistice SSZ-73 became the only airship to fly under a bridge. Maj. Thomas Elmhirst (CO RNAS Anglesey), piloted SSZ-73 under the Menai Suspension Bridge. The act did not harm Elmhurst's career.^[7]

On 16 August 1918, a makeshift SSZ ship was being assembled from the old SSZ-23 envelope and a spare SS Zero car at RNAS Howden airship station.^[8] Petrol fumes from a spillage in the car were ignited some time later by a spark when the radio equipment was being tested, and the ensuing fireball, fed by fuel and gas, completely enveloped and destroyed the old SSZ-23 envelope/spare car hybrid and R23X class airship R27 which were sharing a hangar.^[8] Although the hangar itself survived, one airman lost his life, and two further blimps that were moored nearby, SSZ.38 and SSZ.54, were also destroyed.^[9]

The SSZ's greater stability in flight and longer endurance enabled them to operate in worse weather conditions than had previously been attempted,^[6] and early in 1917 all existing SS types were superseded by the SS Zero.^[2] They were turned out as fast as they could be built, and a total of 77 SSZs were produced between 1916 and 1918, two of which were acquired by France and two by the United States.^[5] The US Navy operated two SSZ's. SSZ-23 (A-1030), and SSZ-24 (A-1029), the SSZ-23 envelope was destroyed in a hangar fire Howden in 1918, SSZ-23 the car was sent from Howden to the US on 4 August 1918.^[10] SSZ-24 apparently burned at Hampton Roads in the summer of 1918.^[11] The SSZ-23 was at Cape May, NJ, for erection on 5 February 1919. The SSZ-23 was withdrawn by mid-1920.^[12]

•  France
•  United Kingdom
  • Royal Navy
•  United States
  • United States Navy

Data from ^[5]

General characteristics

• Crew: 3
• Length: 143 ft 5 in (43.70 m)
• Diameter: 30 ft 0 in (9.10 m)
• Volume: 70,000 cu ft (2,000 m³)
• Useful lift: 1,334 lb (605 kg)
• Powerplant: 1 × Rolls-Royce Hawk , 75 hp (56 kW)

Performance

• Maximum speed: 53 mph (85 km/h, 46 kn)
• Rate of climb: 1,200 ft/min (6.1 m/s)

Armament

• 1 x Lewis Gun
• 2 x 110 lb (50 kg) bombs or 1 x 250 lb (110 kg) bomb

• Comparative specifications for all SS class variants
• British blimps operated by the USN
• List of aircraft of the Royal Naval Air Service

Wikimedia Commons has media related to SSZ class airship.

• SS-class airships on the Airship Heritage Trust website