Dual Mode: 3rd Rail + Catenary locomotive

Does anyone know what it would take to engineer an ALP46a or an ACS64-class locomotive to be able to use either 3rd rail or catenary power?

a new railroad, as the engine would be severely over weight.

Dutch,

That was the essence of my question. Thank you. Please forgive my ignorance on these matters, but what about the DC version of the AEM7's. Could they have operated with a 3rd rail without adding too much weight?

DutchRailnut wrote:a new railroad, as the engine would be severely over weight.

it still would have added a lot of weight , not only shoe beams and shoe mechs but heavy cables, a DC circuit breaker a huge transfer switch a reactance coil , and all control circuitry.
And then still it has to short a wheel base to be usefull.

It's difficult for non-railroaders like myself to grasp things like this sometimes (why cat and third rail can be packaged in an M8 set but not a locomotive). Among other issues, the continued need to support 25Hz AC in the New York area (but which M8 don't) means transformer cores are heavier than they might otherwise be.

Came across this interesting (to me) article about 25 kV 50Hz AC and 750V DC operations in the UK while googling on this.
http://www.railengineer.uk/2013/04/10/h ... d-its-day/" onclick="window.open(this.href);return false;

So is the real problem not having to support two methods of power delivery but two different types of electricity?

After I posted the question, I remembered that the Eurostar supports both 3rd rail and Catenary.

http://en.wikipedia.org/wiki/British_Rail_Class_373

Cool but original poster asked for diesel with both 3th rail and catenary, all other has been off topic.

Dutch, I'm not a railroader, but I have gotten the impression you think you are. Please tell me where the original post mentioned anything that someone with railroad knowledge would think had anything to do with diesel?

you got me, I misread

FRN9 wrote:After I posted the question, I remembered that the Eurostar supports both 3rd rail and Catenary.

http://en.wikipedia.org/wiki/British_Rail_Class_373

Eurostar is EMU though, and they removed the shoes after the High Speed 1 alignment opened.

dowlingm wrote:

FRN9 wrote:After I posted the question, I remembered that the Eurostar supports both 3rd rail and Catenary.

http://en.wikipedia.org/wiki/British_Rail_Class_373

Eurostar is EMU though, and they removed the shoes after the High Speed 1 alignment opened.

Actually it isn't an EMU, it's more like the TGV or Acela with leading and trailing unoccupied (except for the engineer) power cars.

And as far as I know it was successful; the only reason for removing the third-rail equipment was that it no longer operates in third-rail territory.

MBTA blue line subway cars have or had catenary + 3rd rail

How big is a transformer for these electric locomotives, and how much do they weigh? I can't wrap my head around why electric locos aren't much smaller than diesel-electric which has to carry a big diesel + generator

http://www.marthinusen.co.za/uploads/im ... rticle.jpg" onclick="window.open(this.href);return false; for locomotive transformer a unit for a EMU is about 1/7th of that size and still weighs around 20 000 lbs