Tuesday, June 19, 2012

The science of train handling

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Norfolk Southern and New York Air Brake have taken LEADER® from concept to test to proven technology.

Norfolk Southern locomotives certainly look distinctive in their striking black livery with the familiar gleaming white Thoroughbred logo, but for all intents and purposes, at least 1,000 of them could be painted metallic gold. That’s because those 1,000 units have the most potential for their locomotive engineers to achieve the Holy Grail of train handling, the much-desired “Golden Run,” a combination of optimal fuel economy, well-managed in-train forces, and schedule compliance within the parameters of operating rules.

The technology that’s making Golden Runs possible is New York Air Brake’s LEADER® (Locomotive Engineer Assist/Display & Event Recorder), described by NYAB as “the energy management technology of choice for several railroads in the AAR market, providing a complete solution to optimized train handling. LEADER complements the locomotive engineer’s skills by providing a comprehensive view of a train’s behavior with real-time prompts to optimize train movement. ”

Norfolk Southern took the lead with LEADER about six years ago with a test deployment on the “Pumpkin Vine,” a twisty, 105-mile coal route out of Roanoke in the Blue Ridge Mountains on the Winston-Salem District (RA, July 2007, p. 23). Director Operations and Locomotive Coleman Lawrence tells Railway Age NS “is pleased with the results of our deployment of energy management technology to our road locomotive fleet. As we continue to equip our road fleet with the hardware required to support Positive Train Control (LEADER is integrated with the Class I-preferred Wabtec ETMS onboard PTC platform), we plan to apply energy management capability to substantially more than half of our road fleet. Ultimately, we expect to be running energy management software across our entire network. As we expand LEADER coverage, our deployment strategy is guided generally by the gross ton-mile density of the particular corridor, obviously targeting the highest density corridors first.”

To date, NS has seen post-LEADER implementation fuel consumption savings in the mid-single digits range across a variety of train types and territories operating with LEADER. “More specifically, our analysis of post-LEADER implementation train operation indicates just over 6% savings, on a gallons per thousand gross ton-miles basis, compared to the same train types on the same territory before LEADER implementation,” Lawrence says. “These measured savings have been observed with no apparent negative impacts on train speed or schedule adherence. Given the length of the cycles over which benefits in equipment maintenance costs are measured, it is too early in this process to judge what those impacts will ultimately be, but we fully anticipate benefits to materialize over time as variation in train train-handling practices is reduced and general improvement in train handling is realized.”

Train handling in general has improved tremendously in the past 40-odd years. “The reliability of components—wheels, roller bearings, air brakes—has improved,” says NYAB Senior Vice President Marshall Beck. “These are fundamental improvements, but the leaps in train handling have occurred because of three technologies.”

The first of these technologies was DP (distributed power), introduced in the 1970s. DP allows longer and heavier trains to be operated safely. “Over the years, DP has improved,” says Beck. “NYAB began working with Harris (now part of GE) to integrate their Locotrol DP system with our electronic brake. NYAB’s second version of the computer-controlled brake, CCBII, eliminated a manifold, extended COT&S (Clean, Oil, Test & Stencil) to eight years, and improved reliability.”

DP has not been adopted by all Class I’s. “The thing to keep in mind here is that DP is most useful for long trains in hilly territory,” notes Beck. “The railroads decide what length trains produce maximum productivity based on many factors. Length of sidings, type of freight, schedules, terrain, location, and many other factors come into play.”

The second train handling technology is LEADER, where an onboard computer containing consist information (weight, length, and other data); a track profile showing curves, grades, and other data; GPS; and sophisticated algorithms “make real-time decisions on how best to handle a train,” says Beck. The three basics of train handling are to avoid overspeed, run using as little fuel as possible, and limit slack run-in and run-out. LEADER does these things very well. We do a very careful baseline of how the train is handled before LEADER is introduced.”

The third train handling technology is ECP (electronically controlled pneumatic) brakes, with which slack action virtually disappears. NYAB and Wabtec are the suppliers of this technology; both systems are interoperable. Wabtec describes ECP’s benefits as “improved train handling, reduced in-train forces and trip time, and decreased braking distance, service disruptions, and maintenance. Unlike traditional pneumatic brakes, which are initiated from the locomotive and applied to one freight car at a time in a domino-like sequence, ECP uses microprocessor and networking technologies to apply the brakes to each car in the train simultaneously. In this way, ECP eliminates the pushing and pulling of cars against each other during the braking process, which ultimately causes equipment wear and failures, and derailments.”

NYAB’s ECP brake system is EP-60, which is available in a dual-mode overlay version that operates using either radio or wire communication and under standard pneumatic command. “EP-60 provides precise braking, onboard diagnostics, and train status reports on many of the world’s mining companies,” says Beck. “ECP is a remarkable improvement in managing in-train forces, but North American railroads have not adopted the technology in large measure.”

Why are some railroads adopting new training handling technologies and others are not?

“The answer to that question is different for each technology, and every railroad,” says Beck. “However, there are broad themes. One important fact is that North American railroads are working well and are concerned that ECP could have a negative impact on velocity. The issue here is not reliability, but rather, availability of power and shops. ECP is preferred by mining customers around the world in large part because its train handling improves mission reliability.”

ECP “may have stalled out in North America,” observes Beck. Both NYAB and Wabtec have invested many resources in ECP, and have successfully deployed systems overseas—most notably in South Africa at Transnet on iron ore unit trains—but there hasn’t been a whole lot of progress in North America. “PTC has taken over, even though locomotive engineers prefer ECP technology,” says Beck. “Conventional air brake systems must be able to meet the safety and operational criteria of PTC. It’s really just a case of bad timing [for ECP].”

As for LEADER’s future, Beck points out that the technology “is capable of safely controlling a heavy-haul freight train. By that I mean it calculates the throttle, dynamic brake, and air brake needed for a consist. It provides the information necessary to control trains equipped with standard pneumatics, with and without DP, or ECP equipped trains. Later this year, LEADER will add AutoThrottle, where the computer controls the throttle with split-second accuracy. When PTC arrives, a train’s throttle and dynamic brake could be controlled by LEADER-AutoThrottle. Becoming smart, and sensing overspeed andother faults, will be able to hand control back to the engineer.”

Beck reports that UP has placed an order for more than 500 LEADER systems; BNSF for about 200 units.

In Marshall Beck’s estimation, the “perfect train”—one that will make a Golden Run consistently and safely—is one equipped with LEADER and ECP brakes, operating in PTC territory, and employing DP if it consists of at least 120-160 cars.