Sunday, March 28, 2010

436 mpg, and beyond

Written by  William C. Vantuono, Editor-in-Chief
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Can the industry’s much-touted fuel efficiency number be improved?
As locomotive fuel efficiency goes, “436”—the number of miles the industry says one ton of freight can be moved with one gallon of diesel fuel—is a figure that can be improved upon. Some have already bumped the number up to 457. Regardless of what number the industry picks as its poster child, few will dispute that, in terms of its ability to haul goods or people, the diesel-electric locomotive is, so far, the most fuel-efficient form of self-powered land transportation power ever devised.

High, unstable fuel prices are prompting railroads and suppliers to constantly seek ways to squeeze every available drop of fuel efficiency out of a locomotive. That, and the need to meet increasingly stringent emissions regulations, has prompted a virtual explosion of technology. The industry’s principal locomotive builders and engine manufacturers—EMD, GE Transportation, National Railway Equipment Company, MotivePower division of Wabtec. R.J. Corman RailPower, Brookville, Cummins, Caterpillar, Detroit Diesel—have introduced a new generation of power in recent years. A sizeable portion has been developed for the low- to medium-horsepower market, where an aging switcher fleet is gradually being replaced. Gensets and hybrids have entered the mainstream market, and battery- and fuel cell-powered units are being tested. Genset (or “engine-dominant hybrid”) locomotives offered by NREC, MotivePower, and Railpower, and rebuild/upgrade products like EMD’s 710ECO™ Repower, are reshaping the locomotive landscape.

Yet, within the industry’s fleet of roughly 25,000 units, new-tech or experimental power represents only a small fraction. The vast majority of locomotives in service are traditional line-of-road workhorses that travel thousands of miles and burn thousands of gallons of fuel in a given period. For these units, fuel efficiency improvements often depend upon the skilled hands and finely tuned instincts of a locomotive engineer. But even the best, most experienced engineers can use a little assistance. That’s where software-based tools come into play.

The newest of these tools is Locomotive Fuel Optimizer (LFO) from Invensys Rail, now being tested on several Class I and Class II railroads “with consistent results,” according to Vice President, PTC and Locomotive Equipment Rick Soldo. LFO, which works without engineer input, is designed to maximize fuel efficiency in a multiple-unit lashup by automatically making individual throttle notch adjustments to redistribute power among trailing units while the engineer is selecting notches on the lead unit. It continuously monitors and selects the most fuel-efficient notch settings on all trailing units, and, on a typical North American eight-notch throttle, minimizes middle-notch (N3-N7) fuel inefficiencies “without compromising total power, adhesion, or safety.”

Originally developed by Quantum Engineering (which was subsequently acquired by Safetran Systems, now Invensys Rail), LFO, according to Soldo, offers a return on investment within six months through average fuel savings of 2% to 4%. It’s compatible with EMD and GE power, older and newer alike, features automatic calibration, “and works seamlessly with dynamic brakes and Positive Train Control.” LFO will also complement driver-assist systems like New York Air Brake’s LEADER (Locomotive Engineer Assist/Display Event Recorder) and GE’s Trip Optimizer. Soldo calls this “chasing different gallons.”

LEADER, deployed on several dozen Norfolk Southern road locomotives and recently evaluated by BNSF, is an onboard computer/display and off-board data management system designed to improve train handling and yield significant fuel savings (RA, July 2007, p. 23). The onboard database contains a track profile (curves, grades, posted speeds, etc.) that’s merged before each run with a wheel report (number of empties and/or loads, tonnage, power, etc.). During operation, train location is continuously updated with an axle tachometer (for relative positioning) and GPS (for absolute positioning) while LEADER is crunching such data as traction motor current, air brake system pressure, brake propagation throughout the train, and buff and draft forces to determine optimal throttle, service brake, and dynamic brake settings. These settings are provided to the engineer as prompts.

A product of GE’s EcoimginationSM program, Trip Optimizer is described as “an advanced energy management system that optimizes fuel consumption based on a specific train’s makeup and route.” It uses GPS, a digital track database, and advanced track algorithms that automatically learn the train’s characteristics throughout the trip. It evaluates train length, weight, grade, track conditions, weather, and locomotive performance to calculate the most efficient means of operating the train while maintaining good handling. It calculates a fuel-optimal speed profile for a trip and then automatically controls the throttle to maintain that planned speed (cruise control, in effect). Train crews retain responsibility for safe train operation and can engage or disengage the system at any time. Trip Optimizer can be deployed on Evolution Series locomotives as a turnkey system, and can be combined with GE LOCOTROL® Distributed Power.

GE tested Trip Optimizer on 19 Canadian Pacific GE Evolution® Series locomotives in three subdivisions with significantly different geographical characteristics. Revenue-service tests showed fuel savings ranging from 6% to 10%, depending on territory. GE is now equipping 200 CP locomotives.

One of the best (indeed, most obvious) ways to conserve fuel is by shutting down a locomotive during long periods of inactivity, but restarting it before its prime-mover has cooled down to the point where a restart and warmup will actually waste fuel. Automatic Engine Stop Start (AESS) systems have been developed for this purpose. AESS technology is standard equipment on most new-build locomotives, and can be easily retrofitted to unequipped units.

ZTR Control Systems, Inc., has launched its new SAVER™ service for users of its SmartStart®II AESS technology. SmartStart II “is reducing fuel usage on North American railroads by millions of gallons every year,” says ZTR. “This typically results in a 125-ton greenhouse gas emissions reduction achieved by a SmartStart equipped locomotive every year.”

According to ZTR, SAVER-equipped SmartStart systems can automatically provide railroads with fleet performance reports, alerts, and the location of locomotives. The performance reports give a fleet view of fuel savings and reasons for lost fuel savings opportunities. The spreadsheet version of the SmartStart Detail Report is also now available on line if a user would like more information on any single locomotive. In addition, SAVER provides railroads with an online Maintenance Planner, which has scheduling, procedure links, work notes, and followup email capability.

“With SmartStart SAVER, you’ll amplify your payback on the best AESS on the market,” says David Fisher, general sales manager for ZTR’s Railway Division. “This solution uses ruggedized, proven technology to put powerful information at your fingertips.” SAVER is available on new SmartStart II systems and can be retrofitted on existing SmartStart IIs.

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