Free-lance writer Kathy Bergstrom recently checked in with representatives from locomotive manufacturers that serve the U.S. power market. The aim: to provide something of a "state of the state" of the marketplace. Gauging order activity wasn't necessarily the goal — suppliers aren't always able to share such info — but a few undercurrents were pretty clear. One: Order activity has not returned to pre-recession levels. Two: There are some market bright spots — including international orders and the continuing popularity of more fuel-efficient, environmentally friendly generator-set (GenSet) locomotives. For a bit more detail and a few more marketplace threads, read Kathy's story.
I wonder whether genset technology would be appropriate for intercity and suburban service profiles? If so, there are issues of a head end power-compatible module, traction requirements, and the locomotive weight on axles.
Up to 800 kW is needed for head end power that results in a 1,130 hp genset module, roughly twice the size of current modules in switching applications.
Over 3,000 hp for traction is needed for long commuter and intercity trains up to 79 mph, and for short trains up to 110 mph. For speeds of 110 mph for longer trains and for up to 125 mph, two locomotives will be needed.
Four 1,130 hp gensets are needed for hep and traction. 3,390 hp would be available for traction and acceleration; and 2,260 hp still would be available in the event of an engine failure without stranding the train and tying up the railroad. Would four gensets fit in a single unit weighing little enough with axle loads suitable for up to 125 mph? Would 2-axle or 3-axle trucks be needed to achieve the desired axle load, or could that be an option for high speed service?
Thanks, HarveyK400. Thoughts, anyone?
I'd like to offer a follow-up on the genset concept and applicability for intercity commuter and passenger services with an example. Results will vary for train length, gradient, and season.
According to my calculations, a Bombardier TRAXX P160DE ME locomotive modified for Amtrak weighing 90 tons could accelerate a 588 ton, 6-car next-generation bi-level train with just 472 seats to 79 mph in 2.5 miles; but would take 10.3 miles to attain 110 mph. Head end power taken from a static inverter is subtracted from the total 2.4 mW for traction. Only 49% power including winter train heating hep demand, would be needed to maintain 79 mph on a nominal 0.1% grade allowing two gensets to shut down while cruising on nearly level track. The 86% power demand to maintain 110 mph would require all gensets. I assume 75 kW per car comparable to the Amfleet hep load, not having the actual bi-level specifications, but consistent with Amtrak Superliner trains.
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