The slow journey to electronically-controlled pneumatic braking should pick up speed with pending AAR specs. Suppliers are ready. Are the railroads?

By Marybeth Luczak, Associate Editor

	Western Fuels Association, New Mexico, is the most recent company to begin using ECP brakes. WFA is testing ZefTron's cable-based ECP system, which employs the Chameleon� control valve and a Head End Unit cab display (pictured above).

Improved train handling. Reduction of braking distance from 30% to 70%. Instantaneous response from all cars in a train. Graduated brake release. Increased operating speed for reduced trip times. Reduced draft gear, coupler, wheel, and brake shoe wear. Reduced slack action, breakaways, and derailments. Continuous updates of brake system status. Greater fuel efficiency. What more could a freight railroad want from a brake system?

Only a handful are experiencing these benefits of ECP (electronically-controlled pneumatic) brakes first-hand, while the majority are undecided whether to make the switch from conventional pneumatic systems. Why?

"They're waiting for economic justification," explains Fred Carlson, principal investigator at Association of American Railroads affiliate Transportation Technology Center, Inc. "And I can't blame them." Retrofitting existing equipment is not an inexpensive undertaking. Often, too, with new technology, railroads "don't believe it until they see it," adds Bryan McLaughlin, New York Air Brake's EP-60 product manager.

The process of conversion is a slow one. However, as AAR publishes standards providing for open interchange of ECP-equipped railcars, support will likely follow. After six years of development, TTCI issued cable-based ECP specifications in November (S-4200 series) covering system performance, communications protocol, cables and connectors, and head-end power requirements. It expects to finish radio-based specs by spring (S-4300 series) outlining system performance, intra-train communications, onboard power generation, cables and connectors, and radio and antenna performance.

The specs will ensure that all ECP brake components, regardless of manufacturer, operate together in the same train safely and reliably. They also "help ensure the viability of products," says TTCI Senior Engineer Brian Smith, who adds that equipment from cable- and radio-based systems are not intended to be compatible.

Among those that are making the leap to ECP are Burlington Northern and Santa Fe (cable-based), Florida East Coast (radio-based), Canadian Pacific (cable-based), BHP Iron Ore in Western Australia (radio-based), Spoornet, South Africa (cable-based), Quebec Cartier Mining, Canada (cable-based), and, most recently, Western Fuels Association, Inc., Prewitt, N.M. (cable-based).

In December, Western Fuels commenced revenue service operation of a 52-car unit coal train equipped with ZefTron's cable-based ECP system. Three EMD SD40-2 locomotives power the train over a 1.8% grade on an 86.6-mile trip between a power plant and coal mine. The private-car owner has recorded a braking distance of approximately 2.5 miles using conventional pneumatic brakes. So far with ECP, that distance has been cut to just one mile, says Western Fuels New Mexico Operations Supervisor Karl Benz.

"Engineers love it [ECP braking]," says ZefTron General Manager John D. Anderson. "Comments have been, 'I'm getting a whole new perspective on how to operate a train-more versatility.'" During the two-year equipment test, Western Fuels and ZefTron expect to see a decrease in brake shoe wear as well as fuel savings.

The New Mexico project employs ZefTron's lightweight Chameleon� control valve, which may be set in emulation mode, allowing engineers to retain conventional pneumatic brake operation, or pure ECP mode. Both use existing retainer valves and release rods. Railcars equipped with this valve may run in any consist, ECP-equipped or not, easing fleet migration to ECP technology. "Emulation would be a backup in case of irreconcilable loss of communication and would revert to conventional braking," says ZefTron president and CEO Richard F. Murphy. An overlay system-trains equipped with conventional pneumatic brakes plus ECP-is therefore unnecessary.

"ZefTron's Chameleon blends two methods of possible communication, either radio frequency or trainline," says Murphy. Soon, he adds, ZefTron will introduce an onboard generator "powering either the radio frequency/ECP or emulation mode for extended periods of time without detrimentally bleeding the brake pipe."

GE Harris' radio-based EPx� Direct Brake system, whose universal control valve operates conventionally or in ECP mode, is in use on BHP Iron Ore. Each year, the railroad hauls more than 50 million tons of iron ore over its 375-mile Port Hedland-Yandi Mine main line. A 240-car, 37,500-ton iron ore train powered by four GE Dash-8, 4,000-hp diesel-electric locomotives began revenue service in August 1999 with EPx� and LOCOTROL� Distributed Power. Communications are maintained throughout the train with GE Harris' TrainTalk� wireless communications protocol even as it passes though an 1,800-foot iron ore loading tunnel. No onboard repeaters are required.

With EPx�, BHP has cut braking distance by more than 50% compared to LOCOTROL�-only-equipped trains, says GE Harris Product Manager-Railcar Systems Bryan A. Dougherty. (LOCOTROL�-equipped trains provide a 20% improvement over conventional trains). The braking distance for a loaded 220-car ECP-equipped train (BHP's current train length) traveling at 43 mph is approximately 2,000 feet; a loaded 220-car conventional train equipped only with LOCOTROL� requires more than 4,000 feet. Presently, GE Harris is collecting further BHP data using Six Sigma statistical techniques to determine precise fuel savings, trip time, brake shoe wear, and wheel wear.

To maximize ECP braking benefits, developmental testing is under way at GE Harris for a proportional load-way sensor device. The device, which connects directly to the EPx� universal control valve, senses car weight and relays that information to the control valve to adjust braking percentages accordingly, Dougherty explains.

Planned for test on TTCI's 150-car brake rack early this year is the EPx� pneumatically-powered, reduced-weight control valve. "It is a cost-effective solution that allows for seamless and efficient migration to ECP braking," says Dougherty. This next generation control valve "replaces the axle generator and battery with a high-efficiency, air-powered system," says GE Harris. It uses "a negligible amount of brake pipe air, which is converted to electrical energy and stored in long-life, high-efficiency ultra capacitors." The valve will be available by mid-year.

New York Air Brake's cable-based EP-60 ECP brake system is in service on Quebec Cartier Mining. EP-60's stand-alone configuration eliminates pneumatic service and emergency portions, and is lighter weight than an overlay system, according to NYAB. With EP-60, QCM has increased train length from 156 cars to 190 cars without adding extra power. Since the system was installed in January 1998, QCM has seen an increase in ton-miles and up to an 8% savings in fuel, says NYAB's McLaughlin. Presently, 200 of QCM's 1,000-car fleet are equipped with EP-60, with more to be retrofitted.

BNSF also uses NYAB's ECP brake system. In March 1999, the railroad equipped an iron ore taconite train in Superior, Wis., with an overlay EP-60 system. BNSF is now installing EP-60 on another five coal trains that run from the Powder River Basin to northern Minnesota.

The WABCO Railway Electronics Division of Wabtec Corporation began work with South Africa's state-owned railway Spoornet in April 1999 to implement cable-based ECP brakes and distributed power. The equipment will operate over the 248.4-mile Ermelo-Richards Bay Line, a high-density, heavy-haul railroad that transports about 70 million tons of export coal each year. This application "is an extension of WABCO's first cable-based ECP/DPC test train, which was successfully operated on Canadian Pacific Rail in 1999," says WABCO Railway Electronics Director-Freight Car Systems Robert C. Kull.

Testing will begin this month on Spoornet's overlay system-among whose components are an ECP-4201 hardware package, EPIC-II Electronic Air Brake System with an Auxiliary Pneumatic Manifold, PowerLink® Processor for integrated ECP and DPC control, PowerLink Trainline Interface Module, TrainLink EOT, and ECP 230 VDC Power Supply. WABCO will replace the existing pneumatic system "to allow electronic control of all functions as needed for distributed power control, as well as for integration of ECP controls to a common brake handle," says Kull.

Full train commissioning will start in March on a 200-car, 20,000-ton (loaded) train powered by four Hitachi 7E locomotives. According to Kull, among Spoornet's overall objectives are reducing derailments and train break-in-two events, reducing wheel wear, growing line capacity by increasing average trip speed and turn-around, and saving energy.

The overlay configuration of the ECP system "will allow continued use in conventional pneumatic mode when ECP-equipped locomotives are not available," Kull says, and "provides fallback to conventional operation in event of an ECP trainline cable connector break." Additionally, with ECP braking and distributed power, Spoornet will be able mix different generations of locomotives with varying MU specifications within the same consist.

Where ECP technology will appear next is unclear, but "the real push toward implementation will be determined by the benefits in terms of operating efficiencies and reduced costs," TTCI's Smith says.

Hopefully it won't be a long wait.