In 1923, the USS Shenandoah made history as the first American-built rigid airship. Originally commissioned for the US Navy as ZR-1, it was intended for fleet reconnaissance and could spend long hours in flight seeking out enemy ships during World War I.
Much like the German-built airship, L-49, the Shenandoah needed to reach high altitudes to avoid being shot down by enemy aircraft and anti-aircraft artillery. To ensure safety, the airship’s structure was designed to be much sturdier than previous models using a new alloy of copper and aluminum called duralumin.
The Shenandoah was 680 feet in length and weighed a massive 36 tons, enabling it to carry up to 2,115,174 cubic feet of lifting gas inside its 20 gas cells. Unlike other zeppelins, which used flammable hydrogen to inflate, ZR-1 was the first airship to utilize non-flammable helium as lifting gas, protecting it against explosions. It was powered by five Packard 6-cylinder engines as well as large, custom-designed wooden propellers manufactured by Hartzell Propeller.
ZR-1’s first missions were long-range reconnaissance flights through inclement weather to search for enemy ships. With its ability to fly at high altitudes and low speeds without suffering damage from harsh storms, the airship soon earned a reputation for its endurance and safety.
In 1924, ZR-1 became the first rigid airship to fly successfully across North America when it made the 19-day journey from New Jersey to California. However, because helium was expensive and relatively scarce, the airship was modified to remove 10 of its 18 gas valves, which limited the amount of gas that was released as the airship gained altitude.
On its 57th flight, the Shenandoah was caught in a storm over Ohio and crashed. The airship’s recent modifications were thought to have caused structural failings leading to the incident. Despite this setback, the Shenandoah marks the US Navy’s first experience with rigid airships, ultimately contributing to the design of the most successful airship in American history, the USS Los Angeles.
See the complete Hartzell history timeline here.