Coastal class airship

Coastal class
Role	Patrol airship
National origin	United Kingdom
Manufacturer	RNAS Kingsnorth
First flight	1916
Introduction	1916
Retired	1918
Primary user	Royal Naval Air Service
Number built	35
Variants	C Star class

The Coastal Class (often known as the C-Class or simply the 'Coastals') were a class of non-rigid airship or "blimp" used by the Royal Naval Air Service (RNAS) 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. Entering service in 1916, the Coastal class remained in widespread service until 1918, with a few members of the class still in service at the signing of the Armistice, while others were replaced by the improved C-Star class as they became unfit for service. The blimps were used for long anti-submarine patrols in the Western Approaches and English Channel, protecting convoys from German U-Boats. The Coastal class was one of the first aircraft types specifically designed to detect and attack submarines.

The C-Class was far from a new design. The prototype was built in 1915 by using the envelope from the No. 10 Astra-Torres airship, and a gondola built using the front-sections of two Avro seaplane fuselages joined together back-to-back to provide one tractor- and one pusher propeller. The envelope was composed of rubber-proofed fabric that was also doped to hold the gas and resist the effects of weather, and had a distinctive trilobe shape in which the two lower lobes were situated side-by-side, and the third was positioned centrally above them.

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