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WNY&P AC6000CW units

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WNY&P AC6000CW units
Posted by JOHN DE CAROLIS on Saturday, September 7, 2019 5:04 PM

Just got the new Trains magazine, and was reading the caption to WNY&P 6002 as a "5,800-hp Gevo-equipped unit". Apologies in advance, as I know nothing about modern diesels, so here's my question. Some years back, during the horsepower race, GE and EMD got to the 5,000-6000 hp mark. Then, if I remember correctly, railroads weren't enthralled, and thus have now standardized around 4,400 hp. So what is 'Gevo', and is 5,800 hp 'too much', reliability (or other)-wise, given the 4,400 benchmark?

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Posted by Overmod on Sunday, September 8, 2019 2:23 PM

JOHN DE CAROLIS
So what is 'Gevo', and is 5,800 hp 'too much', reliability (or other)-wise, given the 4,400 benchmark?

Think of GEVO as shorthand for "GE Evolution".  This is the engine family (similar in some details to the "HDL" that was developed out of the Deutz MWM632) that is in the Evolution Series and later locomotives.  Most of the engines built were 12-cylinder engines that were virtual drop-in replacements for the famed 7FDL engines in the first round of 4400hp GE locomotives.  But a few were 16-cylinder twin-turbocharged engines, and CSX opted to derate some of its 16s (to ~4600hp) instead of replacing the engines as most other users of AC6000s and the like seem to have done.  

It would be relatively simple to 're-rate' a 16-cylinder GEVO back to its 5800hp, and that would appear to have been done if the picture captions are correct.  (Note that this is the same nominal horsepower as the SD80MAC which uses four more cylinders to produce it.)

The initial 6000hp engines from both EMD (that is, the 16-265H and not the 20-cylinder 710 in the SD80MACs) and GE suffered from cavitation issues, which you can think of as ultrasonic frequency vibrations due to concentration of engine force in portions of the crankcase and engine structure which form microbubbles in the coolant that selectively erode away the casting 'from within'.  Apparently there were also issues with the main bearings on the HDL-16s, an issue that was addressed by lengthening the main bearings slightly on the GEVO-16 which also made the engine slightly longer overall.  There are several people on this list who have read the papers on the detail design of this engine family who can comment in much more exact detail (please have them e-mail me the papers if they have them scanned!)

4400hp was a sort of 'sweet spot' in that two locomotives 'cabs out' were just the right power for an average-length train in the late 1990s, but two 6000hp even with adequate wheelslip control were too much capacity, but one was not quite enough.  In addition any kind of failure taking 6000hp out of service would cause delay to the associated train, probably no matter what its length, with more impact than a comparable unit failure of 4400hp.  

Even with the advent of monster PSR consists there doesn't seem to be much interest so far among Class Is in locomotives with the GEVO-16 installed.  That makes this WNY&P locomotive, if it is actually re-rated, particularly interesting.  Note that typical power on this road is large six-motor Alcos, but 6002 is nearly equal to two C-630s at the re-rated horsepower, implying considerable savings in both consist 'wear and tear' and fuel consumption, and of course has much more modern and sophisticated drive electrics.  

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Posted by JOHN DE CAROLIS on Sunday, September 8, 2019 3:56 PM

Overmod-thanks so much for enlightening me! 

WNY&P, in going down this path, is departing from conventional (Class 1) thinking, perhaps because of their typical motive power preference, road profile, and possibly 'the price is right'...wonder how well these new units will co, especially since the Class 1s don't seem interested.

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Posted by Leo_Ames on Sunday, September 8, 2019 5:14 PM

Overmod
But a few were 16-cylinder twin-turbocharged engines, and CSX opted to derate some of its 16s (to ~4600hp) instead of replacing the engines as most other users of AC6000s and the like seem to have done.  

It's worth pointing out for others even though I know you know this, that the engine you're talking about here originally was a replacement engine. CSX replaced the engines in their AC6000CW fleet like the other two operators also did.

CSX repowered their production fleet of AC6000CW's with 16 cylinder GEVO's (As did BHP, I believe) to replace the disastrous 7HDL16 they had been constructed with, while the three preproduction prototypes were repowered with 16 cylinder FDL's just like Union Pacific had installed in their fleet.

The 16 cylinder GEVO isn't a bad engine, but the problem came about a short time after getting repowered back around when that recession in 2008 hit. CSX suddenly decided a small fleet of ~6000 hp locomotives was a luxury that they couldn't afford, so derated them to save on fuel.

So CSX ended up with small fleet of what in most regards performed no better than an ES44AC and which utilized ES44AC components, yet it had the added cost of 4 more cylinders to maintain than an ES44AC, slightly worse fuel economy, and some unique components that weren't shared with any other members of their fleet of GE power.

That decision to derate them and move them into general service was the beginning of the end and they became some of the first units to be parked whenever there was a downturn in traffic and mechanically they ended up neglected over the past decade, leaving them in the sorry shape they're in today. 

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Posted by Overmod on Sunday, September 8, 2019 8:05 PM

Leo_Ames
It's worth pointing out for others even though I know you know this, that the engine you're talking about here originally was a replacement engine.

Thank you. 

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Posted by M636C on Sunday, September 8, 2019 8:12 PM

CSX repowered their production fleet of AC6000CW's with 16 cylinder GEVO's (As did BHP, I believe) to replace the disastrous 7HDL16 they had been constructed with...

BHP (at the time BHP Billiton) rebuilt their AC6000CWs in 2006.

The HDL had a distinctive "hollow" exhaust note, such that you could tell a train with a an AC6000CW leading before it came into view. Whether this sound was linked to the problems with the HDL, which from GE's publicity concerning the GEVO included insufficiently rigid crankcases, and I think cavitation, just as in the 265H I can't say.

The GEVO-16 sounded more or less like an FDL and this gave an indication of what engine was fitted. If you caught a rebuilt AC 6000CW shortly after the rebuild, the silver paint on the twin stacks hadn't burn't off and gave an indication if the locomotive was idling of what engine was fitted.

The BHP locomotives were a special low clearance version with angled cab sides at window level, and even larger radiators that projected over the rear walkway.

They were all scrapped in 2014-5, within sight of the Fortescue Metals line who were importing SD90MAC-H locomotives at the time. BHP didn't wan't to sell locomotives to a competitor, and preferred to scrap the units.

Peter

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