Amtrak RFP for new/rebuilt locomotives

frequentflyer said:

jis said:

Why do you believe Autotrain cannot be operated using SC-44s? could you provide a credible citation in support of your fears?

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I am sure the Chargers with 4K hp and AC traction motors could handle Autotrain, but doesn't the P40s have a modified braking system that makes handling a longer train easier? Using thoroughbreds as it were instead of quarter horses.

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There is nothing that prevents setting up a few Chargers with freight braking system, just a like a few P40s are probably set up that way.

So on the whole it is just a non issue IMHO.

Both P40s and Chargers have almost the same HP, the Chargers being nominally more powerful by 150HP (4400 vs. 4250). The Charger has a starting tractive effort of 290kN (vs. 280kN for P42), 275 kN Continuous (vs. 169 kN for P42). And to top it all, it loads way faster than a P42. On the whole the Charger is a much more capable locomotive than the P42.

RPC said:

jis said:

I was just wondering what the value of reusing the body shell and trucks is since apparently both the prime mover and the electric drive is projected to be replaced.

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I believe that a "rebuild" only has to meet the environmental regulations in effect at the time of original manufacture.

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The announcement said that the diesels acquired through this process will have better environmental performance. It did not say that this applies only to new engines AFAIR.

The Chargers, at least the ones Brightline have, does have the ability to switch to Passenger or Freight braking. There is a switch between the Electronic Brake Valve and the Independent Brake.

At least, that is what I observed when I was on one of the units last year.

IMHO

If Amtrak is ever to be on a "sustainable" basis it makes sense to have the locomotive (and rail car) fleets replaced on an incremental basis rather than try to come up with funding when everything is worn out and is becomes an emergency. Plus it allows a build up of a small fleet of "reserve" units for limited use that can fill in at peak times (aka available to be a third unit if needed for a PV move, and allow said PV moves).

cpotisch said:

Seems like this is already being discussed here.

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And, the topics have been merged.

chrsjrcj said:

The Chargers, at least the ones Brightline have, does have the ability to switch to Passenger or Freight braking. There is a switch between the Electronic Brake Valve and the Independent Brake.

At least, that is what I observed when I was on one of the units last year.

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To my knowledge, all Siemens locomotives built for the US market have the same brake stand.

jis said:

Both P40s and Chargers have almost the same HP, the Chargers being nominally more powerful by 150HP (4400 vs. 4250). The Charger has a starting tractive effort of 290kN (vs. 280kN for P42), 275 kN Continuous (vs. 169 kN for P42). And to top it all, it loads way faster than a P42. On the whole the Charger is a much more capable locomotive than the P42.

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The boilerplate power rating alone doesn't tell you everything. You would need to see the tractive effort curves of both types and compare them. I don't know if those are in the public domain.

With the improvements in software, power electronics and three-phase drives that have occured in the intermediate years, I would assume the Chargers to be superior in all regards. But assuming is not the same as knowing,

cirdan said:

jis said:

Both P40s and Chargers have almost the same HP, the Chargers being nominally more powerful by 150HP (4400 vs. 4250). The Charger has a starting tractive effort of 290kN (vs. 280kN for P42), 275 kN Continuous (vs. 169 kN for P42). And to top it all, it loads way faster than a P42. On the whole the Charger is a much more capable locomotive than the P42.

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The boilerplate power rating alone doesn't tell you everything. You would need to see the tractive effort curves of both types and compare them. I don't know if those are in the public domain.

With the improvements in software, power electronics and three-phase drives that have occured in the intermediate years, I would assume the Chargers to be superior in all regards. But assuming is not the same as knowing,

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That is why I gave the published tractive effort information. [emoji57]

jis said:

cirdan said:

jis said:

Both P40s and Chargers have almost the same HP, the Chargers being nominally more powerful by 150HP (4400 vs. 4250). The Charger has a starting tractive effort of 290kN (vs. 280kN for P42), 275 kN Continuous (vs. 169 kN for P42). And to top it all, it loads way faster than a P42. On the whole the Charger is a much more capable locomotive than the P42.

Click to expand...

The boilerplate power rating alone doesn't tell you everything. You would need to see the tractive effort curves of both types and compare them. I don't know if those are in the public domain.

With the improvements in software, power electronics and three-phase drives that have occured in the intermediate years, I would assume the Chargers to be superior in all regards. But assuming is not the same as knowing,

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That is why I gave the published tractive effort information. [emoji57]

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but still, seeing the full curve would tell us more than just knowing two points.

Also, such things as wheelslip recovery might limit a locomotives ability to apply full tractive effort.

All of that is true. But that does not mean one has to wait until every piece of information is available, to arrive at reasonable conclusions based on information that is available [emoji57]