triple expansion engine
(formerly) a steam engine in which the steam is expanded in three stages in cylinders of increasing diameter to accommodate the increasing volume of the steam
Read more in this article about some frequently asked questions and fun facts related to our definitions.
Why are planes named after numbers, like the 747? Is there a 947 or a 658?
After World War II, one of the largest aircraft manufacturers, Boeing, turned its attention from designing military craft to building commercial planes, along with missiles and spaceships. (Unrelated fact: when Boeing was forced to spin off its passenger flight division, the newly-formed company became United Airlines. Back to the late 1940s: Model numbers were assigned to each division of aircraft (from the Boeing website:) “300s …
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012