Turntables such as those mentioned by Bill were/are common in locomotive and car shops, where they are used to move trucks from one track to another where an overhead crane is not present. There is one in front of the wheel lathe in the East Broad Top's shop at Rockhill Furnace, Pa., for example. In previous times, such turntables, usually narrow gauge, were often used in lieu of switches in foundries, breweries, brickyards, planing mills, etc., where four-wheel pushcars were used to move materials around. There are several of these turntables in the old DL&W freighthouse in Scranton, Pa., now used as offices by Steamtown NHS. They look like oversize manhole covers with flangeways at 90 degrees from each other.