TIME Magazine content is available exclusively for TIME subscribers.

Current subscribers for full access. Not a TIME subscriber? .

Science: Contradictory Screws

Like one of the fastest airplanes that ever flew,† the two-man Japanese submarines which attacked Pearl Harbor had contrarotating propellers —two tandem screws placed close together, turning in opposite directions. Blades on the second screw are pitched counter to those of the other screw so that both thrust in the same direction. Such devices for U.S. warplanes were announced last week to be "in the developmental stage" by Curtiss-Wright, United Aircraft, other plane builders.

Purpose of this mechanism in planes (and submarines) is to overcome torque or sideways twist created when 1) the air's...

Time.com on Digg

POWERED BY digg

Quotes of the Day »

DAVID CAMERON, British Prime Minister, on England's soccer manager, Fabio Capello, who resigned after challenging the FA's decision to strip John Terry of the captaincy; Terry denies a charge of racially abusing QPR's Anton Ferdinand
For use in rail of Articles page or Section Fronts pages. Duplicate and change name as necesssary to distinguish.