Twin Span Turntables (Railroad): Description, Specifications and Advantages produced by the Bethlehem Steel Bridge Corporation, Bethlehem, PA dated 1921. Publication is in reverse blueprint blue color pages with a linen type front/rear cover. Pages are numbered 1D - 5D for Description section; 1S - 5S for Specification section; 1A - 4A for Advantages section; and 1C - 5C for Costing section. Publication includes two fold out plans: one depicting a comparison of turntables Twin Span vs. Balanced; and the second fold-out is a plan and profile of a standard 100Ft. Turntable - Twin Span Type. Publication is 8 1/2" x 11" in size. Excellent general overall condition. $30.00 cash payment at local pick-up only in Blairstown, NJ