Re: [SystemSafety] Lac-Megantic disaster

From: Matt Squair < >
Date: Thu, 11 Jul 2013 20:14:19 +1000

Ah, an excellent question.

There are locomotives which use APUs but it depends on a number of factors including a ROI question. If you're operating in very cold weather then the need to keep main engine coolant temperatures above freezing may make make an APU attractive because it can also heat the coolant circuit. Some operators go down this path.

However you have to find real estate and there's a maintenance cost etc etc. So if you're operating in warmer weather primarily then the option of up rating your battery banks and using the main engine is more attractive. In Oz, we universally work with battery based AESS rather than APUs for freight.

Which raises an interesting point that had this been mid winter all the locomotives would have been idling at some point or another and therefore available for charging the main reservoir. But it was summer, so only one needed to be available. Hmmm.

Matt Squair
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On Thursday, 11 July 2013 at 7:54 PM, Peter Bernard Ladkin wrote:

> On 7/11/13 11:48 AM, Matt Squair wrote:
> > The actual reason has to do with operational efficiency as it takes time to pump up a trains
> > reservoirs from ambient. Leave one loco on to run its air compressor and you can get away quickly in
> > the morning.
> >
> > Of course if all the needed park brakes aren't applied and then for some reason the online loco is
> > shutdown...
> >
> > As a side note, an increasing number of locomotives have what's called an Auto Engine Start Stop
> > function to save fuel. With AESS the locomotives control system will monitor air reservoir pressure
> > and only start the main engine if needed to run the air compressor. Modern freight trains are quite
> > sophisticated and complicated systems.
> >
> I dunno about sophistication. Why isn't there an APU for such functions?
> Prof. Peter Bernard Ladkin, Faculty of Technology, University of Bielefeld, 33594 Bielefeld, Germany
> Tel+msg +49 (0)521 880 7319
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Received on Thu Jul 11 2013 - 12:14:49 CEST

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