GPF39-3

[Anonymous]

For a freight railroad would reducing a F40PH's horsepower from 3,000 to 2,300 be economical? Three thousand horsepower is near the limit of a 4 axle locomotive and 2,300 horsepower would save some fuel. Also it would stop slipping caused by high horsepower or heavy tonnage.

keep asking, keep learning

[Anonymous]

Terry, you are going to get the same responces here as on Railroad.net. No, it isn't economical, 3000 hp is NOT near the limit of a 4 axle locomotive, the limit is more in the range of 3500-4000 hp. Sand and new computerized wheelslip control systems keep the wheels from slipping anyway. Also, turbocharging an engine actually helps to IMPROVE fuel efficiency. Plus full cowl locomotives are no good to a freight RR, as they can't be used for any type of local work, or yard switching, they are restricted from that type of work by federal law. Last, but not least, the spec. would be F39-3, or M-3, not GPF39-3

[Anonymous]

That was my next question.

Would it be possible to de turbo the reduced horsepower GPF39-3's E.M.D. 645 from 2,300 horsepower to 1,500 horsepower in a GPF38-3? Would it still need a roots blower? That way a freight railroad would be able to stop wheel slip, save fuel, and reduce maintenance if they could eliminate both the turbo and roots blower.

keep asking, keep learning

[Anonymous]

The roots blower is a natural part of and EMD. They won't run without them or the geared turbo. And as for your other senerio, If you derate a 645 that usually involves removing the turbo. When you do that you start out with a GP-40 or SD-40 at 3000hp and end up with a GP-38 or SD-38 at 2000hp.
The company called Speno ( now called Pandrol Jackson ) took some F-40PH's and de-turboed them to 2000hp for pulling their rail grinding trains.

[M636C]

To get a "39" from a "40", you need to replace the 16-645E3 with a 12-645E3.

This was done in the first MARC commuter engines, where GP40s were rebuilt into RP39-2H (or something like that) by replacing the sixteen cylinder by a twelve. This left enough room to install a HEP diesel generator, which was cooled by the third fan that wasn't needed for the smaller radiator for the smaller prime mover.

Later MARC units kept the 16-645E3, and had the frame lengthened to accommodate the HEP diesel generator.

I think VRE use the same two types of locomotive.

But these are both passenger units. There have not been many "medium power" units bought for freight use (except switchers) in recent years.

Peter

[CSSHEGEWISCH]

As mentioned above, a roots blower is absolutely necessary for any 2-cycle diesel engine, be it a 567, 645, or OP.

De-turbocharging a 12-645 engine would bring it down to 1500 HP, same as an SW1500 or GP15-1.