Royal Navy C23 Coastal Airship, c 1917.

Model. Mostly powered by 150 hp Sunbeam engines, those that survived the war were scrapped in 1919. The C23 was 200 feet long and had an envelope capacity of 170,000 cubic feet. A close up with a side view of the gondola and propulsion system fashioned from two Avro 504 fuselage sections.