USS Akron (ZRS-4)
In 1928 the Goodyear-Zeppelin Corporation signed contracts with the Bureau of Aeronautics to build two large fleet-type rigid airships capable of carrying airplanes for scouting purposes.
The first of the two was the USS Akron.
The ACRON ZRS-4 and the MACON ZRS-5 carried small scout planes called sparrow hawks. Watch this video to see the Akron in action.
Design and Construction
Following the loss of the ZR-1, Shenandoah, in September of 1925 the Navy Bureau of Aeronautics, with Admiral William A. Moffett as its chief, recommended a comprehensive program of rigid airship development. This plan called for the construction of two large rigid airships and a West Coast LTA base. The navy's General Board was less enthusiastic, however, and when the matter was referred to them they recommended only one rigid airship, and only if the funds were provided outside the navy's normal appropriations.
This token nod to the rigid airship was unacceptable to Admiral Moffett who in response had a House bill introduced which called for a replacement ship for the Shenandoah built with funds from the regular navy budget. Congressional hearings followed and resulted in the navy's Five Year Aircraft Program, which included authorization for two large rigids, becoming law on June 24th, 1926. Appropriations, however, were not made available until 1927. In that year design submissions for a large rigid airship scout were requested. The winner of the competition was Goodyear-Zeppelin's entry.
Coincidentally with the construction of the LZ-126, Los Angeles, for the U.S. Navy, the Zeppelin Company's head Dr. Hugo Eckener entered into an agreement in October 1923 with the Goodyear Corporation. Under the agreement the Goodyear-Zeppelin Company of Akron, Ohio, was to be given North American rights to the Zeppelin Company's patents as well as key Zeppelin personnel to bring the Zeppelin Company's long experience in rigid airship design and construction to the New World. In exchange, the Zeppelin company was given ten percent of Goodyear-Zeppelin's stock and the knowledge that no matter what the Zeppelin Company's future would be in the uncertain economy of post-war Germany, the rigid airship would have a future.
The noisy protest of the American Brown Boveri Electric Corporation, however, caused another competition to be held in 1928, but the result was the same. Goodyear-Zeppelin, under the direction of Dr. Karl Arnstein, one of the thirteen key personnel of the Zeppelin Company sent to America, had created an innovative design for the largest airship yet constructed.
Goodyear-Zeppelin's design called for a ship of 6,850,000 million cubic feet, 785 feet long with a maximum diameter of 132 feet, 11 inches. The ship was full of innovations. Rather than standard Zeppelin main rings, the ship had much sturdier deep main frames which dispensed with the miles of radial wiring which reinforced the Zeppelin main frames. In addition, the ship had three keels, as opposed to the one which had been standard up to that time. One keel was placed along the top of the ship, with the remaining two 45º below the horizontal. These provided unparalleled access to all parts of the ship as well as tremendous strength. The lessons of the Shenandoah and R-38 had been well learned.
The most innovative feature of this design was the ability of the airship to launch, retrieve, and service five aircraft for scouting purposes. Approximately one-third of the way aft was an internal hangar, approximately seventy-five feet long, sixty feet wide, and sixteen feet wide. Through a T-shaped opening in the floor of the hangar a trapeze could be lowered onto which the ships five airplanes could be launched and retrieved from "sky hooks" attached to the top of the airplanes. Operating as the airship's eyes, these scout planes extended the scouting area tremendously. More importantly, they
allowed the vulnerable airship to remain far from an enemy's carrier based fighter planes.
The crew's quarters were on either side of the airplane hangar and included a mess, galley, washroom, and sleeping quarters for both officers and enlisted men. The crew's quarters were heated by the cooling water from the engines, a first in rigid airships. A small control car was built into the hull fore. An emergency control station was provided in the lower fin.
Because the ship was designed from the outset for inflation with nonflammable helium-a gas which then only the U.S. had in quantity-the ship's eight 560 hp Maybach VL-2 engines were installed within the hull along the two lower keels. They each drove a propeller at the end of a sixteen foot outrigger. As the engines were reversible and the
outrigger could swivel the propeller through an 90 degree arc, thrust could be delivered in any direction for aiding landings.
Construction of the new ZRS-4, later christened the Akron, began on November 7, 1929 at the new Goodyear-Zeppelin Airdock in Akron. Assembly was similar to that of other airships. The main rings were assembled on the floor of the hangar and hoisted into place then connected by longitudinals. The exterior of the airship was then covered with cotton fabric and doped.
Several small changes were requested by the navy, but only one significant. This involved the fins. In. Dr. Arnstein's original design the ships fins were long and slender, attached to three of the ships main frames. However, this design would not allow the captain in the control car to see the lower fin and check his ship's trim. Thus a design change-Change Order No. 2-was made, shortening and deepening the fins and moving the control car back eight feet. As a result the fins were now only attached to two main frames. The new fins also negated the design loads figures, which were later found to be too low. However the navy opted to leave the design unmodified.
By late summer 1931 the Akron was complete, and was christened on August 5. On September 23rd, with Lieutenant Commander Charles E. Rosendahl in command the Akron took to the skies for the first time.