Tanker trucks, also known as tenders, are used by more than 65% of all fire departments across America. Early tankers were converted from oil, fuel, milk, or chemical tank trucks. Some of these converted units were semi or tractor-trailer trucks, others were smaller, local oil or milk delivery trucks. Large fire apparatus manufacturers started to manufacture water tanker fire trucks in the late 1950s, but it wasn't until the 1970s that custom-made water tankers became popular. Shown are tankers by all the major and minor fire apparatus manufacturers and regional builders, among conversions built by local shops. Included are tankers from Mack, Ford, GMC, Chevy, International, White, Brockway, Diamond T & Reo, Autocar, Kenworth, Peterbuilt, Freightliner, Volvo, UD, Marmom, Western Star, Crane Carrier Corp., FWD, Oshkosh, AMC, and others.