I must confess I was thinking more in terms of maximizing 'reuse' of locomotives that are already built, and minimizing the expense of returning the engines to diesel service if that is ever undertaken.
I can easily see one of the 'objections' to LNG being that the price may get jacked up to historical levels if any one of a variety of things brings the current 'glut' to an end. There needs to be a clear, and imho as cost-effective as possible, return path from either any experimentation or any fleet conversion. I am not entirely sure that full second-sourcing engines and support for them is the 'best' alternative to make that possible.
On the other hand, if any conversions to genset engines are made, it would be completely logical to use ignition motors in them as the initial 'replacements', as I expect the cost of the gas motors to be considerably less than diesel equivalents (ceteris paribus) and there should be less required maintenance in a number of respects.
RME
Overmod CSSHEGEWISCH When you consider that many financial prognosticators believe that the low natural gas prices won't last, it will be interesting to see how far BNSF (or anyone else) will continue with this development. See also the post in General Discussion on this subject. One potential 'argument' is the relative ease with which engines can be converted to run on natural gas (and be converted back to diesel if required), and with which fuel 'tenders' of appropriate (large volumetric) capacity can be built -- with the assumption they can be either re-used for some cryo service or restored to 'ordinary' condition. I would say, imho, neither of those things poses particular difficulty. My introduction to this was that our college 'crew tank' was driven by a Cat diesel that had been converted/perverted to burn normal distributed 'house gas'. I did not take careful note of how the ignition was handled, but it's a simple matter to arrange a spark via a 'surface gap' igniter (as in turbojet engine practice) through the now-unused fuel-injection port in the head for each cylinder. (Laser ignition is now a low-cost technology although not yet commonly recognized as such). The lower compression ratio issue can be handled with deck-height increase or spacers, or at worst changing pistons/rods/crank to suit when the engine is overhauled. Presumably regenerative heating will be used to re-liquefy the gas and bring it up to ignition temperature, with some 'electric' or externally-fired assist when starting or in severe weather -- I doubt this would be too far removed from what something like a Hotstart now does for coolant. While tanks could be converted from 'conventional' tankers, or cryo cars, by re-insulating them and armoring the shell against derailment damage, it may be better to purpose-build the things -- with the understanding they will be serviceable as cryo cars themselves if not in use as fuel tenders. RME P.S. There are reasons I prefer LNG to CNG, and this in itself is an interesting topic that I'd like to add to this discusssion.
CSSHEGEWISCH When you consider that many financial prognosticators believe that the low natural gas prices won't last, it will be interesting to see how far BNSF (or anyone else) will continue with this development.
When you consider that many financial prognosticators believe that the low natural gas prices won't last, it will be interesting to see how far BNSF (or anyone else) will continue with this development.
See also the post in General Discussion on this subject.
One potential 'argument' is the relative ease with which engines can be converted to run on natural gas (and be converted back to diesel if required), and with which fuel 'tenders' of appropriate (large volumetric) capacity can be built -- with the assumption they can be either re-used for some cryo service or restored to 'ordinary' condition. I would say, imho, neither of those things poses particular difficulty.
My introduction to this was that our college 'crew tank' was driven by a Cat diesel that had been converted/perverted to burn normal distributed 'house gas'. I did not take careful note of how the ignition was handled, but it's a simple matter to arrange a spark via a 'surface gap' igniter (as in turbojet engine practice) through the now-unused fuel-injection port in the head for each cylinder. (Laser ignition is now a low-cost technology although not yet commonly recognized as such). The lower compression ratio issue can be handled with deck-height increase or spacers, or at worst changing pistons/rods/crank to suit when the engine is overhauled. Presumably regenerative heating will be used to re-liquefy the gas and bring it up to ignition temperature, with some 'electric' or externally-fired assist when starting or in severe weather -- I doubt this would be too far removed from what something like a Hotstart now does for coolant.
While tanks could be converted from 'conventional' tankers, or cryo cars, by re-insulating them and armoring the shell against derailment damage, it may be better to purpose-build the things -- with the understanding they will be serviceable as cryo cars themselves if not in use as fuel tenders.
P.S. There are reasons I prefer LNG to CNG, and this in itself is an interesting topic that I'd like to add to this discusssion.
Caterpillar already offers a range of Spark initiated Natural Gas engines so there is really no new tech needed. GE bought an Austrian Comapny called Jenbacher which makes both diesel and gas engines of appropriate sizes for locomotive use (in fact one of the diesel models powers GE's POWERHAUL series locomotives being built for the UK/European market.
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
P.S. There are reasons I prefer LNG to CNG, and this in itself is an interesting topic that I'd like to add to this discussion.
By Russell Gold, on page B-1, cols. 5 - 6, and B-2, cols. 1-2, in the March 6, 2013 print edition; on-line version last updated March 5, 2013:
Link: http://online.wsj.com/article/SB10001424127887324539404578342540494619344.html
Note also the 64 comments (as of this moment) to the article on another 'tab' at the top.
From the middle of the article (and I've posted this statistic over in the "General Discussion" Forum before) - emphasis added:
"A gallon of diesel fuel cost an average of $3.97 last year, according to federal statistics. The equivalent amount of energy in natural gas cost 48 cents at industrial prices."
For a diesel unit using 1,000 gallons of fuel per day, that could be a fuel cost saving of about $3,500 per day [1,000 x ($3.97 - $0.48) ]. For even just 1,000 units of that 6,900 unit BNSF fleet, that would be as much as $3.5 Million per day !
- Paul North.
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