Airships—often termed blimps—were popular in the U.S. Navy for more than four decades. The service’s first “gasbag” was the DN-1 developed during World War I for the antisubmarine role.
The Navy developed specifications for an airship, and a contact was awarded to the Connecticut Aircraft Company of New Haven on 1 June 1915. Although the United States had not yet entered the war, the threat of German U-boats prompted the service to consider a large number of potential countermeasures.
The Navy’s specifications were based in part on the German Parseval. In contrast to the better-known Zeppelins, the Parsevals were nonrigid or semirigid airships, with little or no stiffening structure inside their fabric envelopes. The Zeppelins had a rigid internal framework made of duralumin.
No one in the U.S. Navy at that time is believed to have had experience with airships, and the Connecticut firm had an Austrian pilot and a German mechanic who claimed knowledge in the field. Thus, by any criteria, constructing the DN-1—the designation indicating Dirigible, Navy—was an experimental project.1 The $45,646 contract called for delivery of the airship in 1915, but inexperience on the part of the Navy and the builder delayed delivery until December 1916. The unassembled airship was shipped to Pensacola, Florida, and put together in a floating hangar that had been constructed specifically to support the DN-1. The first flight did not occur until 20 April 1917.
The DN-1 envelope was fabricated of two layers of cloth with rubber sandwiched between; the outer cloth layer was yellow to prevent deterioration from sunlight. The envelope had two “ballonets” with a 1½-horsepower engine to maintain air pressure in the airship when the main engines were turned off. Propulsion and air pressure were provided by twin 140-horsepower engines, with propellers that could swivel in the horizontal and vertical planes.
The open gondola or control car was watertight and boat-shaped to enable the DN-1 to operate from the water as well as from land. The airship was designed to both attach to a mooring mast and enter her floating hangar.
As flight tests began, disappointment was immediate: The airship was barely able to attain her designed airspeed of 35 miles per hour. The transmission overheated, melting bearings. The envelope leaked gas. And the airship was overweight. In an effort to lighten her, one of the engines was removed.
A week later, on 27 April 1917, the DN-1 flew for the second time. A third flight was made on the 29th, and that day, as sailors were attempting to tow the aircraft on the water, she was damaged. The decision was made not to repair the airship, and she was scrapped.
Subsequently, Jane’s All the World’s Aircraft called the DN-1 of no practical value and noted that she was interesting only as an experiment. That was an apt description of the U.S. Navy’s first airship attempt.
1. Some documents list the designation as indicating Dirigible, Nonrigid, No. 1. After her demise, the DN-1 was considered the Navy’s “A” series, with the next airship design being labeled the “B” series.
