Integrated Railmotive Systems Inc.

Excellence in Engineering


    There are two different, though compatible, coupler and draft systems used by the North American railroads today. These are the AAR standard type E and the alternate standard type F.  The F is a more modern design with better slack control and better behavior in train action, but the E is simpler and less expensive.  The F is a tightlock design, so when the couplers are mated, they lock together to support one another more or less as a single drawbar.
    This means that the relative vertical motion of one type F coupler relative to its mate as the cars themselves bounce up and down when in motion, is restricted to about a half inch. By comparison, the same car motion, were the cars to be connected by type E couplers, would be as much as five inches. This makes it tough to design an automatic Brake pipe connector to properly operate with the large vertical and lateral motions allowed by the design of the E. Such a connector would be desirable to get rid of the need for manually connecting this vital conduit, but attempts to provide one always run into high cost and complexity. 

Railmotive designed the combined air and electric connector shown in Exhibit 18-1 for application to the high capacity gondola discussed elsewhere on this site, because we had found that a significant improvement in train turn-around time could be made if ECP braking was used on the cars.
    Most cars intended for unloading in rotary dumpers use the F coupler. This is because the F, with its above mentioned drawbar like behavior, makes it relatively simple to design a rotary coupling which will permit rolling a car over in such a dumper, without requiring uncoupling of the car from its train. Given this inherent advantage of the F type arrangement in this service, Railmotive designed the illustrated attachment even though it could only be used with F couplers, because in unit train operation it is not too difficult to arrange for all cars in the service to be equipped with specialties, such as the subject connector.  With an entire fleet of cars able to automatically connect and disconnect trainlines without manual intervention, there is a big economic payoff.  This is because not requiring a man to enter the space between cars to couple them both speeds operations and reduces injuries to trainmen.
    Of course it is desirable to be able to use the cars in non-ECP equipped trains, so it would be necessary to provide an adapter which would allow the use of either conventional air hoses or the full automation illustrated here. There are several ways in which this can be done, depending on the particulars of the desired service.  The concept is presented to show the possibilities and the capability of Railmotive in dealing with them to provide better performance and dollar returns for our customer.