Science: Pinch & Jet Ship

Ship propellers, churning out their wakes with magnificent forcefulness. look pretty efficient. But John H. MacMillan Jr., president of Cargill, Inc. of Minneapolis, suspected them of churning a little too turbulently. Since Cargill is a grain firm, deeply involved in water transportation, MacMillan decided to save his company some money by improving its ships' propellers. Last week he described a system that he believes gets more propulsive effect out of a ship's engine.

Key to the system is two deep grooves built into the hull near the ship's stern (see diagram). They converge toward the propeller, and when the ship is in...

Want the full story?

Subscribe Now

Subscribe
Subscribe

Learn more about the benefits of being a TIME subscriber

If you are already a subscriber sign up — registration is free!