 The MH-1A was designed as a towed craft because it was expected to stay anchored for most of its life, making it uneconomical to keep the ship's own propulsion system.It contained a single-loop pressurized water reactor, in a 350-ton containment vessel, using low enriched uranium (4% to 7% 235U) as fuel.The MH-1A had an elaborate analog-computer-powered simulator installed at Fort Belvoir.