Freight car components: the innovators - includes related article on electro-pneumatic braking - Cover Story

Railway Age, Feb, 1996 by Gus Welty

From bearings to brake systems, from couplers to cushioning devices, the high-tech freight car continues to take shape as suppliers respond to customer demands.

"Explosion of new technology" is a phrase you might expect to see applied to cyber-stuff, telecommunications, probes out into the universe. But it's not out of line to use that same phrase to describe what's happening, and what's going to happen. in the things that really make freight cars perform--and we're talking trucks, bearings, couplers and draft gear, cushioning devices, brake systems, all those things that have to work as a system before the car and the train can perform to the optimum.

The new-tech, high-tech that's coming along is impressive.

* Improved trucks. Consider, first, freight car trucks. Conventional wisdom has it that the conventional three piece truck's time has come. and should be going. The key word maybe "conventional." because among major truck manufacturers there's a lot going on that's at least somewhat unconventional.

American Steel Foundries, for example, is ready to go to the marketplace with its SuperService RideMaster truck, designed for 286,000-pound weight on rail and combining what ASF regards as the best features of its SuperService and RideMaster designs. This is a variable-damped truck with the SuperService shoe design, which improves squaring of the truck. It's expected to reduce maintenance costs and to significantly add to wheel life, perhaps by as much as 30%.

The only price premium will involve a SuperService RideMaster with stress reducing design geometry that allows a reduction of about 10% in total truck weight. On a unit coal train, for example, ASF figures that the advantages of lower truck weight, increased payload capacity, increased wheel life, and other maintenance cost reductions will give a payback on the premium cost in less than a year.

And actually. ASF is looking at the new truck as a universal design for broad application, one that will make it possible for railroads and others to further standardize on truck design.

Standard Car Truck, meanwhile, went through a lot of developmental work and testing on radial trucks, with excellent results in terms of wheel wear reductions, fuel savings, and rollability. Weight and cost considerations, so it's said, weighed against the radial truck, and Standard Car Truck then began looking for a way to get similar results without the perceived penalties, and the frame-braced truck was the outcome.

This is a design that's become extremely popular in Canada and, after making ride quality evaluations at the Transportation Technology Center, TTX will be installing frame-braced trucks under a number of motor vehicle cars this year. One of TTX's main goals regarding ride quality is to improve vertical ride quality, and the manufacturer believes that improvements can be made in this area with use of frame-brace trucks.

* A role for composites? At the same time. Standard Car Truck has formed an alliance with Lockheed to develop a freight car truck using high strength composite materials. Composites have been used for truck components in Europe, in applications and an operating environment a lot different. But SCT and Lockheed will be working on a design, and presentations have been made to at least four railroads, one or more of which might decide to enter into a "strategic alliance" to help with the development.

As for the National Castings unit of NACO, Inc., it will be getting an assist in its concentration on high performance truck development from the newly formed NACO Technologies.

Over the years, while its designers have concentrated on structural designs to provide fatigue strength, they've also worked on ride quality improvements, including improved capabilities in curving and high speed operations. One important factor: Translation of the best features of passenger car trucks into freight car truck design. including rigid H-frame design, swing hanger suspension, and optimized vertical and lateral damping, with a steered-axle function incorporated in some designs.

National Castings' Swing Motion truck, one current design, got Canadian National's vote for use on its intermodal Laser trains, it's used in the RoadRailer Mark V system, and it's being installed under most new TTX autorack cars. TTX has also gone out on its own to improve truck performance, opening a truck machining center at its Draco Shop in Michigan. What TTX is seeking is more precise machining of sideframes and bolsters on three piece trucks to provide better ride quality for a longer period of time, and it believes that this facility (Cincinnati Milicron was the primary contractor) will provide the kind of consistent quality it's looking for.

The technology to improve truck side bearings has also been much improved.

Constant contact side bearings have been in use for many years, but as demands have changed so has the technology. W. H. Miner Division of Miner Enterprises, for instance, came out with its TCC side bearings, designed to eliminate truck hunting. But when articulated cars were introduced, it became clear that increased side bearing travel would be needed in order to allow for free torsional movement of the carbody. Miner then introduced its TCC-II line of long-travel side bearings that has the additional travel to permit freedom in torsional movement of the carbody units and improve performance during curving.