What is the difference between the KC Brakes and the AB Brakes. What time period would you find these braking systems in?
Tom Makofski
Menasha, Wisconsin
Hi Tom, The simplest explanation is that the KC brake is an all-in-one device incorporating the brake cylinder, air reservoir, and triple valve in one unit. It gets more complicated because it was contemporary with the KD system, which had a separate brake cylinder and a reservoir/triple valve unit. K brakes were widely used from the early 1900s until 1953, when they were finally banned from interchange service. The AB came later than the K system, worked better, and is the basis for brake systems still in use today (ABD, ABDW, and ABDX). The AB brake is a three-part system comprising a brake cylinder, a two-part reservoir with separate compartments for service and emergency applications, and an AB (NOT “triple”) brake valve which also had separate sections for service and emergency applications mounted together on a central pipe bracket. AB brakes were introduced in 1930 and adopted as the standard for new construction in 1932 – no cars were built with K brakes after 1931. There were several earlier deadlines for the elimination of K brakes from interchange service, but they kept being postponed because of a) the Depression, b) WWII, and c) postwar equipment shortages and manufacturing delays. Even after 1953, K brakes could still be found on non-interchange equipment which wasn’t used in interline service, such as work equipment and many cabooses. Happy New Year, Andy
Thanks Andy. That’s the info I wanted.
Merry Christmas!
Tom