Historical Perspective: The X-1

By DAVID F. WINKLER

Dr. Winkler is a historian with the Naval Historical Foundation.

In January 1962, the Navy commissioned SEAL (SEa Air Land) Team One on the West Coast and SEAL Team Two on the East Coast as units trained and equipped for unconventional warfare, counter-insurgency, and clandestine operations missions in both open-ocean and coastal environments. The new units drew men from the famed Underwater Demolition Teams (UDTs) of World War II. These Navy "Frogmen" distinguished themselves by conducting reconnaissance and obstacle-destruction missions in the vanguard of amphibious landings, during both World War II and Korea.

A challenge for both the UDT and follow-on SEAL units has been to insert the teams in a quick but clandestine manner while minimizing the physical strain on personnel. Over the decades SEAL Delivery Vehicles (SDVs) have increased dramatically in both range and capability. The most recent addition to the inventory, the Advanced SEAL Delivery System (ASDS), has greater range and speed than its predecessors and can carry more men and equipment to the area targeted.

An antecedent to this sophisticated delivery vehicle was the USS X-1. Impressed with the effectiveness of the British midget "X" craft attacks against the German battleship Tirpitz­which was berthed in Norway during World War II­the U.S. Navy contracted with the Fairchild Engine and Airplane Company to build an American midget submarine. Launched on 7 September 1955 at Oyster Bay, N.Y., the 49-foot, seven-inch craft, which had a seven-foot beam, entered service a month later under the command of Lt. Kevin Hanlon.

All submarines of that era, with the exception of the recently commissioned USS Nautilus (SSN 571), ran on air-fed diesel engines on the surface and on battery power when submerged. Besides propelling the boat on the surface, the diesel engines also recharged the batteries. What made the X-1 unique was her use of hydrogen peroxide instead of air as an oxidant. This enabled the mini-sub to operate her diesel engine under the surface, a huge advantage in time of war. However, when Lt. Kinnaird McKee received orders to relieve Hanlon as X-1's commanding officer, he was told that the boat was going to be put out of commission for the somewhat vague but nonetheless compelling reason that "it doesn't work." It seemed that the diesel engine was breaking up after operating for only a few hours with hydrogen peroxide.

For McKee, the possibility of losing his first command was not a happy prospect. On a quick trip to the Bureau of Ships, McKee obtained $48,000 in additional funding, which enabled him to conduct new engine tests at the Portsmouth Naval Shipyard in New Hampshire.

After a series of extensive tests, McKee and his crew discovered that condensed steam (water) was backing into the diesel chambers, causing the engine blocks to crack. After modifications were made to drain the water, the engine worked fine.

McKee had applied earlier for the nuclear propulsion program and was rejected, but suddenly found himself back in Washington being interviewed by then-Rear Adm. Hyman G. Rickover, the legendary "godfather" of the Navy's nuclear propulsion program. Because he was looking forward to operating X-1 with the UDT divers down in Little Creek, VA, McKee had little enthusiasm for joining Rickover's program.

However, the possibility of using the X-1 as a diver delivery vehicle never came to fruition. On 20 May 1955, McKee recalled, he was eating supper when he received a phone call from the duty petty officer: "Captain, you had better get down here quick!"

"What's the problem?" "The boat just blew up!"

Unfortunately, the polyvinyl chloride bag that contained the hydrogen peroxide had sprung a leak, spilling the highly unstable substance onto a silver-brazed pipe. The violent chemical reaction that followed sheared the bolts connecting the boat's forward section. One observer watched the X-1's nose plunge into Portsmouth harbor and rapidly sink.

In its later life, the X-1, fitted with a standard diesel-electric propulsion system, served as a test platform and was then transferred to the U.S. Naval Academy, where she is mounted as an outdoor static display.

As for McKee, the subsequent investigation absolved him of fault and he did enter the nuclear propulsion program. He did reasonably well after what seems to have been a most inauspicious start, succeeding Rickover, by then a four-star admiral, in 1982 as director of the Naval Nuclear Propulsion Program.

Information for this article is taken primarily from Dr. Winkler's Oral History interview with Adm. McKee in March 2000. The author thanks Mark Wertheimer of the Naval Historical Center for his assistance with this article.