The U.S. Navy began acquiring non-rigid airships toward the end of the 1920s. The first non-rigid airship it acquired was an unusual airship because it was metal-clad -- the ZMC-2. Although technically a rigid airship, the ZMC-2 was classed by Navy as non-rigid since gas pressure maintained the shape. Built by the Aircraft Development Corporation of Detroit, Michigan, the ZMC-2 was the only metal-clad airship built.

The ZMC-2 was the brainchild of Ralph Hazlett Upson, the chief engineer of Aircraft Development Corp., an extraordinary man whose vision spanned the range of aerospace history from lighter-than-air flight, through the development of the airplane and into that of space exploration. He eventually retired from Boeing after a career as a leading engineer for that company.

The theory behind this unorthodox metal-clad design was that a welded duralumin gasbag would eliminate seepage, provide greater strength, and do away with the necessity of hangar shelter. The skin of the ZMC-2 was made form aluminum alloy plates one-hundredth of an inch thick; and the envelope, just shy of 150 feet long, was the direct container of the helium -- a highly prized, rare and expensive commodity at that time.

If the design proved itself, Aircraft Development was prepared to build a 100-ton metalclad, 550 feet long, that would do 100 mph.

Congress approved an appropriation of $300,000 for the development and building of the airship and the Navy awarded the contract to Detroit Aircraft Corporation.

This interesting experiment in all-metal airship design and manufacturing had been promoted by the Aircraft Development Corporation of Detroit, Michigan and it was no coincidence that Ford, that is Edsel Ford, William May and William Stout, invested in the venture in an effort to make Detroit the manufacturing center of the dirigible industry. The name of the company was even changed to reflect this goal. It was renamed Detroit Aircraft Corporation and was under the direction of Edward Evans, president.

The Ford name was not closely associated with the ZMC-2 at the insistence of Henry and Edsel Ford, but Ford laboratories, on the property of the newly-completed Ford Airport (near Deerborn) conducted tests on the ZMC-2 and paid $500,000 for the 225-foot dirigible mooring at Ford's airport.

The ZMC-2 was built in a hangar at the Naval Reserve Air Station at Grosse Ile, Michigan, near Detroit.

The ZMC-2 first flew on 20 August, 1929 and was delivered to the Navy on 12 September, at Lakehurst Naval Air Station, New Jersey. The Navy then conducted numerous flight tests. As a sub-scale test vehicle, the ZMC-2 was proved successful, although it was somewhat hard to control during rough air. It was strange looking for a blimp, being teardrop-shaped, and it had eight small stabilizer fins, four of which had control surfaces which acted as rudders. Navy crews soon nicknamed the airship the "Tin Bubble" or the "Tinship."

The ZMC-2 shares Hangar No.1 at NAS Lakehurst with the German passenger airship LZ-129 Hindenburg. The immense size of the Hindenburg dwarfs the metalclad.

Over the next twelve years, the ZMC-2 operated with the Fleet, performing well. When it was scrapped in 1941, it had completed 752 flights and accumulated more than 2,200 flight hours.


Two photographs showing the ZMC-2 flying in formation with U.S.S. Los Angeles (ZR-3) and a J-2 blimp during maneuvers off Atlantic City, New Jersey, 11 October 1930. (click on the images for larger views)

So, why didn't the success of the ZMC-2 lead to larger, better and more efficient metal airships? The disastrous loss of the U.S.S. Akron (ZR-4) and the U.S.S. Macon (ZR-5) airships in the mid-1930s put an end to the Navy's interest in large airships. The smaller non-rigid blimps proved themselves in the coming war and for years afterwards, but interest in rigid airships had passed.

Despite it's apparent successful design, there was little interest in pursuing a successor to the ZMC-2. Detroit Aircraft Corporation went bankrupt in 1931 and eventually became a part of Evans Products Co.

At the same time the ZMC-2 was being built, another concern was exploring the concept of metalclad airships.

In Glendale, California Benton Slate was building the Slate All-Metal Airship (MD-2) which featured a corrugated skin, an innovative steam propulsion systems and a number of other innovations. The world's largest form press was assembled at Grand Central Airport to build this airship.

Specifications
Manufacturer: Aircraft Development Corporation
Length: 149 ft. 4 in.
Diameter: 52 ft. 7 in.
Capacity: 200,000 cu. ft. (helium)
Powerplant: two 300 hp Wright J-5 Whirlwind engines
Max speed: 70 mph
Cruising speed: 52 mph.
First flight: 20 August, 1929.