Saipan windmill washers, also called windwashers, were improvised washing machines built by U.S. Marines and Seabees on Saipan, Tinian, and elsewhere in the Pacific theater in 1944.
It took almost month -- from June 15 until July 9 of 1944, for the Marines to take Saipan from Japan. The battle pitted 127,000 troops against an entrenched force of 32,000 Japanese fighters, almost all of whom were killed. The fighting was filthy and, by the end, everybody needed to clean their clothes.
Traditionally, Marines had cleaned their clothes by scrubbing them by hand in rivers or buckets or in their helmets. (The same helmets that they cooked in, brushed their teeth in, and wore on their heads when the Japanese started shooting).
It was probably the Seabees who built the first windwasher -- a Rube Goldberg-esque device that connected a propeller (made of wood or perhaps an actual propeller from a downed Japanese fighter) via a crankshaft (salvaged from some junked piece of machinery), to a plunging device, which could have been a one quart bucket or a helmet. This was held aloft by a frame that positioned the plunger over a drum (typically a 55 gallon fuel drum that had been cut in half and had a hole drilled in the bottom for a tapered wooden drain plug). The plunger followed guiderails nailed to the frame, and the entire operation was held together with cotter pins and washers. Some of the fancier models used salvaged gears to achieve a faster plunge rate.
Once the first windwasher had been built, copies appeared across the Pacific theater. The Seabees could be bribed to build them with salvaged Japanese equipment, or the Marines would build them themselves.
In a 10 to 15 mph wind, one of these devices could finish a load of laundry in about an hour. However, the devices were positioned to capture the best wind possible and, especially in a storm, they could do the job faster. In the Fall 2002 issue of Invention and Technology, a Marine named Gene Tabor describes leaving his uniform in a windwasher overnight, and coming back to discover that the machine had torn it into microscopic shreds.
Necessity is ever the mother of invention, and World War II drove innovation in weaponry, rocketry, computer science, atomic science, and other areas. It is kind of wonderful to think about some of the toughest soldiers the world has ever known, in one of the most brutal campaigns, sitting over wind-powered washing machines that they had designed and built themselves.
source: American Heritage of Invention and Technology, Fall 2002.