A Shipwrecked Miami Couple Owe Their Lives to a Clever Gadget That Makes Seawater Drinkable
updated 10/02/1989 AT 01:00 AM EDT
•originally published 10/02/1989 AT 01:00 AM EDT
The Butlers' ordeal began on June 15, two months into their round-the-world sail, when their 40-foot yacht was attacked and sunk by whales some 1,200 miles off Costa Rica. Scrambling into their rubber raft, they barely had time to grab a little food, some fishing gear and the Survivor-35, which is a manually operated pump for converting saltwater to fresh. For more than two months they subsisted mostly on raw fish and a precious three liters of potable water that William Butler, 60, squeezed out of the Survivor each day.
The principle behind the Survivor is not new; it's a process called reverse osmosis, in which brackish water is forced through a semipermeable membrane that blocks the salt but passes the liquid. In the past, however, all such systems were huge, motorized devices pumping at pressures of up to 1,000 pounds per square inch. And all were clearly impractical for lifeboat use.
Then last year, Dick Hembree, now 36, of Recovery Engineering in Minneapolis, completed a novel design: an easily portable desalinating pump that could be hand operated by a single person. Inspired by a prototype started by the late Bill Wanner, a fellow Minneapolis engineer, Hembree developed a pump that sucks seawater through a tube and forces it through the membrane with a lever-driven piston. But water is circulated behind the piston as well, thereby balancing the pressure on the piston's face. As a result, the Survivor-35 (price: $1,295) requires no more exertion to operate than a bicycle pump.
"All the time I was designing the pump," says Hembree, "I thought of people in situations like the Butlers'." And the French-born Simone, now safe in Miami with her husband, responds with a supreme accolade. She grew up near the famous spa at Evian and knows good water. How was the Survivor's version? "Excellent," she says. "Just delicious."