Les Jones

Science > Neat Science and History: Pykrete

CABINET MAGAZINE: The British planned massive ice ships and ice aircraft carriers during World War II. The ships were to be made - not from steel - from ice, and not from ordinary ice, but from Pykrete, the creation of eccentric inventor Geoffrey Pyke.

Pykrete is a super-ice, strengthened tremendously by mixing in wood pulp as it freezes. By freezing a slurry of 14 percent wood pulp, the mechanical strength of ice rockets up to a fairly consistent 70 kg/sq cm. A 7.69 mm rifle bullet, when fired into pure ice, will penetrate to a depth of about 36 cm. Fired into pykrete, it will penetrate less than half as far - about the same distance as a bullet fired into brickwork. Yet you can mold pykrete into blocks from the simplest materials and then plane it, just like wood. And it has tremendous crush resistance: a one-inch column of the stuff will support an automobile. Moreover, it takes much longer to melt than pure ice. But as strong and eco-friendly as it is, pykrete remains forgotten today save among glaciologists, who express bafflement over why no one has made use of it. "I don't really know why it has languished in obscurity," admits Professor Erland Schulson, director of the Ice Research Laboratory at Dartmouth College.

Found via Jason Kottke's web site.