RE: (erielack) Re: Walthers Bethlehem Flush-Deck Cars: First Impression

["Paul Brezicki" <doctorpb_@_bellsouth.net>]

Here's part two of the much-condensed "flush-deck primer" dealing with the related subjects of cushioning, hitches and end-aprons, also known as bridge plates. I was thinking that if you model this equipment, you may want to print these posts for future reference (don't wait for my article because I may never get around to it!).

Since it's impossible to cushion container brackets, cars with container-handling equipment must have end-of -car cushioning (the center sill of long flats prevents application of cushion-underframe). This includes the TTAX and TTCX cars. TTX cars generally have friction draft gear and cushioned hitches; the others have rigid (ie non-cushioned) hitches because they have ECC. TTX cars have 48" bridge plates located on the left side of each end. TTAX cars have 60" BP's in the usual position plus short "auxilliary" BP's on the right side. This is because with circus loading, the slack is generally pulled out and then the brakes are set, so the cushion couplers allow a wider gap; the travel is 15" for cars in TOFC-COFC service (10" in autorack and other applications).

There were many styles and models of hitches used over the years, and a little history is in order. Prior to 1955, RR's used a variety of kingpin pedestals, combined with clamps and tie-down chains to secure the trailer, all of which made ramping and deramping a time-consuming, labor intensive activity. ACF revolutionized the process with the Model A hitch, which was raised and lowered with a pneumatic screw mechanism; a hand-operated screw clamped the hitch plate securely on the kingpin. This eliminated the need for the other hardware and the resulting efficiency boosted TOFC growth (many anxious mechanical dept folks insisted on continued use of "disaster chains", but this practice died out during the 60's). The Model A was replaced by the Model 2 in 1961; ACF hitches were used in all TOFC cars (except the G-85's and G-89's) until the late 60's.

The "All-Purpose" car of 1968 necessitated new hitch designs that sat lower on the deck when retracted to clear containers secured to deck pedestals. ACF introduced the Model 5, and Pullman-Standard entered the hitch market with the LP-3 (rigid) and LP-6 (cushioned) hitches. At this time TT began to color-code hitches as an aid to ramp personnel: black for screw-operated top plates (all ACF's) and orange for top plates that automatically lock on the kingpin (P-S).

The final installment will deal specifically with the new Walthers cars. Stay tuned!

Paul B

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