Re: Boxcar #3132 Question....

The best place to get the answers about this type of system is in Dr. Sloan's book Century plus 10 of D&RGW freight Cars. He has the 1903 blueprints showing the piping used on the KD system.

Another possibility is in the Prospector magazine. Bill Merideth(sp) did an article on 4000 series box cars, and one of the plans sheets included the layout of the KD brake system.

In 1903 the 3000s were indeed delivered with KD brakes, and the system included a bypass pipe that alowed use of either straight air or automatic air. The prints I've seen show the branch pipe with a T in it. One line goes to the triple valve, then the reservoir, and the other goes to the bypass line around the res, and into a T located between the res and cylinder. Three valves used. One valve at each end of the res, and the other in the middle of the bypass pipe.

For straight air, you open the one in the bypass, and close the two aruond the res. For automatic, it is the opposite.

I've often wondered why the railroad went to the expense of changing to the KC, especially considering it required them to jack up the two queenposts for the truss rod that goes over the combined cylinder. It must have eliminated some periodic maintenance and/or leaks, is the only thing I can figure.

There are still a number of 4000 series boxes, and 6000 flats that had KD systems to the end. However, most of these were in company service in those later years.