Ralph Mosher was born in 1920 in Watervliet, New York, a suburb of Albany, and a short distance from General Electric’s giant industrial park in Schenectady. Mosher served in World War II and earned a Bachelor’s degree in Mechanical Engineering from the University of New Hampshire. With his wife Priscilla, he had three daughters. He then joined the General Electric research laboratory in Schenectady, and worked in close proximity to a publicist for the research laboratory – a young Kurt Vonnegut Jr.
Mosher was assigned to work on manipulators for military use on such projects as the B-72 nuclear-powered aircraft. In 1956, he created the Yes Man, which was “the most dexterous mechanical slave ever developed.” The device had arms with elbows that bent, wrists that swiveled, and three-clawed hands, and parroted the actions of a human who acted out the desired motions in pantomime in a set of control arms. Electrical signals in the control arms activated hydraulic pistons that moved the Yes Man’s claws in the same way. By watching the Yes Man through a TV, a technician sitting a distance away could safely guide the Yes Man through intricate tasks in an atomic laboratory. Yes Man was referred to as a “cybernetic anthropomorphous machine” or “CAM.”
Mosher next developed the Handyman, in 1959, which could twirl a hula hoop. Each of the Handyman’s two arms was capable of 10 different types of motion: finger bends, finger curls, thumb bends, thumb curls, wrist bends, forearm twists, elbow bends, upper arm twists, and forward and sideward pivots int eh shoulder joints. The Handyman was capable of actual tasks, such as steadying a block of wood with one claw while the other claw held a hammer to drive in a nail. The robot was designed to be used with a series of wires running through concrete walls at a nuclear plant, and weighed 550 pounds. Though the robot was put into production at some of GE’s own facilities, the concept needed too much refinement and weighed too much to be taken elsewhere.
Mosher also developed the Man-Mate CAM 1600 industrial boom for material handling, which allowed an operator to “feel” material he handled and react instinctively to the material with the ease of lifting a lightweight object by hand. Basic to the touch feature, was a Sens-A-Lift, electro-hydraulic servo control system.
Once the Vietnam War started, the U.S. Army asked GE and Mosher to create a full-body exoskeleton for them, which was called the Human Augmentation Research and Development Investigation Manipulator, or “Hardiman.” Hardiman gave an operator a 25:1 force ratio – a human exerting 60 pounds of force could lift 1500 pounds. The Hardiman was ideal for loading heavy weaponry into aircraft, but no full Hardiman ever made it past prototype. One arm with nine joints was built and successfully tested, but the legs remained problematic.
In 1969, and after 5 years of additional Army contracts, Mosher and GE produced “The Fabulous Walking Truck.” The 3,000-pound walking truck could balance on 2 legs, and walk over and around large obstacles and turn around. The walking truck topped out at a speed of 5 miles per hour, could carry a 500-pound payload, and could lift loads up to 500 pounds on one foot. Alternatively, the truck could drag a 1,000-pound load across a floor. The truck was powered by a 90-horsepower gasoline engine that drove a pump for a high-pressure hydraulic system that moved the legs by hydraulic actuators. The actuator servos were hydromechanical and needed no electronic elements.
About 10-15 hours of training were required to properly operate the Walking Truck, and only Mosher ever mastered its operation. He bragged, “You imagine you are crawling along the grounds on all fours, but with incredible strength.” However, the Walking Truck suffered from practical problems. The sheer physical force required to operate the truck drained human operators within fifteen minutes. The long spindly legs of the Walking Truck required great precision, to avoid landing on uneven turf; the operator couldn’t see the turf, so such precision was next to impossible. Additionally, so much hydraulic fluid was required during operation that the Walking Truck could not hold enough for sustained movement. While in the laboratory, General Electric could hook up external tanks of fluid, the military saw the problem with the fluid demands. Only a single prototype was completed, and never got outside the building. The Walking Truck can been seen today in the U.S. Army Transportation Museum in Fort Eustis, Virginia.
In 1972, Mosher left GE to start up his own company, Robotics, Inc. He began making robots for use in plastic injection molding and dye casting operations. When he ran into a cash-flow squeeze and the 1974-75 recession, he began to produce a parts-transfer device, The Shape Maker. Mosher also noted that the U.S. automobile industry was switching from cork gaskets in car engines to using liquid sealant, and Mosher developed a device that could seal auto engine gaskets with a wide degree of versatility.
In 1982, he moved to Clearwater, Florida, and died in 2008.
One can only imagine Mosher sitting in a dark movie theater as the AT-ATs came into view to prelude the Battle on Hoth during the beginning of The Empire Strikes Back. Did he recognize his Walking Truck in the Imperial battle vehicles? Though none of his inventions at General Electric entered production, Mosher’s fascination with human-amplifying robotics made a unique contribution to pop culture history.