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  • Marketed but never sold EMD types

  • Discussion of Electro-Motive locomotive products and technology, past and present. Official web site can be found here: http://www.emdiesels.com/.
Discussion of Electro-Motive locomotive products and technology, past and present. Official web site can be found here: http://www.emdiesels.com/.

Moderator: GOLDEN-ARM

 #608502  by Jtgshu
 
The problem with those higher HP numbers is adhesion -

While its can't be directly compared to a diesel, I frequently run ALP44s and ALP46s, with 7000 plus HP in passenger service. For those who don't know, they are 4 axle locos. While they are much lighter than a diesel loco, they still have tremendous wheel slip issues. The '46 has computer contolled wheel slip/slide systems, and are designed to put as much power as possible to the rail, however, as soon as the wheel hits a not so great spot in the rail heads condition, it slips.

Even the PL42AC, which is a diesel 4 axle loco manufactured by Alstom, but uses an EMD powerplant (V16 - 710) has wheel slip issues. There is much debate as to why the loco has wheel slip issues, and which system is at fault (if one at all) but the fact remains that its still there. Maybe its the gearing, maybe its the size of the wheels, whatver, I dunno, but its annoying, and it hurts the performance of the loco.

Im not familar with how the higher HP locos in the freight world work with traction, as I don't run them, but 6 axles im sure helps, and the heavier weight of them as well im sure helps with adhesion, But there is going to be a point at one time or another where the weight needed for good adhesion compared to the power being put out by the loco are gonna be at odds.

Maybe some new wheel slip/slide system is in the future adn will solve all our problems, but I dunno about that. You still have a polished steel wheel on polished steel rail, and not all laws of physics can be altered by a few grains of sand!