“Railroad Facts” published by the Association of American Railroads (AAR) show that fuel burned by North American Class 1 railroads in diesel-electric freight service exceeded 18.45 litres, accounting for 13% of overall operations expense at 2007 fuel prices. While the current hiatus in fuel prices has provided some operating cost relief, long-term trends in fuel prices will almost certainly cause the expense and percentages to rise. To improve efficiency, performance of locomotive components such as the diesel prime-mover and electrical power conversion in the traction system have made an incremental impact over the past 20 years. Even hybrid technologies to recover braking energy have been developed, but this option awaits improvements in cost and life expectancy of batteries before wide penetration in a locomotive fleet can be realised. In this context, GE and other suppliers have set out to develop system level control strategies to reduce energy consumption, focusing on how the train can be driven for fuel (and emissions) use reduction while satisfying operating constraints of schedule, the rolling stock and track infrastructure.

GE’s Trip Optimiser is a locomotive control system enhancement applicable to diesel-electric hauled freight that can achieve double-digit fuel savings. Energy savings derive from managing train momentum, with anticipation of its effects, to reduce the net energy outlay by the train as it completes a trip. GE’s system has two major components: the first is a planning system that derives an optimal way to drive the train (throttle together with a corresponding speed trajectory versus distance) subject to speed restrictions along the route and locomotive operating constraints; the second is a dynamic control system that executes the plan closed-loop, correcting for modelling errors from various sources and assuring proper train handling consistent with railway requirements. To compute a plan, information about the track to be traversed (grade and curvature versus distance marker), the power consist make-up (number and type of operational locomotives) and load (tonnage, train length etc) is required together with updated speed restrictions, work crew locations, and other constraints that vary from day-to-day. The Trip Optimiser system has been implemented on GE Evolution series locomotives.

Related posts:

1. GE’s Trip Optimizer product – IHHA – Best Paper
2. GE’S EVOLUTION SERIES LOCO: 6% FUEL ADVANTAGE
3. NEW GE DIESELS FOR SOUTH AFRICA
4. THE MODAL DEBATE
5. UK GOVT TO SELL £16BN’S WORTH INCLUDING HS RAIL
6. GE’S EVOLUTION® V12 DIESELS CERTIFIED BY UIC
7. MTU 4000 SERIES ENGINE
8. A TRIP ON SHOSHOLOZA MEYL