Once steam engines went out of style, SS started to stand for "single-screw ship," referring to a vessel powered by a single screw or propeller.

Steam engine weighs more than a million pounds Twenty-five Big Boys were built exclusively for Union Pacific Railroad, the first of which was delivered in 1941. Big Boy No. 4014 was delivered to Union ...

WITH a puff of steam, a shrill whistle, and a rhythmic chug, the newly-restored SR Merchant Navy class locomotive proved that even after 84 years she can still turn heads.