Trains on the Pokey today

NW Mailing List nw-mailing-list at
Fri Apr 10 06:26:00 EDT 2009

> Wow! I had no idea that they were achieving adhesion ratios in the

> mid 40s these days!


> pete groom

An AC traction motor has the ability to get much higher into the static curve than a DC motor does... however, you do need pretty good rail/wheel conditions... while the mid 40s and even higher is possible, I believe it's the exception rather than the rule... I'd say the average is more like .38-.4... which is better than a DC motor, but current DCs are no slouches either.

Given the average static coefficient of friction of steel on steel is around .65 - .7 or so dry, it may very well be possible to see adhesion ratios in the mid 50s in the coming years as motor control and the motors themselves get more and more refined... though the rail/wheel interface will become even more of an issue at that point.
Robb Fisher



> On Apr 9, 2009, at 12:20 AM, NW Mailing List wrote:


> > > what is the CTE software?

> > > Nathan Simmons

> >

> >

> > Controlled Tractive Effort... reduces the TE curve from 145,000pds

> > to 110,000pds when the unit is below 11mph. Normally used in DPU

> > operation on manifests on other roads... however, it would make

> > sense for it to be enabled even when manned, given that these units

> > are max axle load units (432,000lbs) and have the high-adhesion

> > software set to 36,000/200,000 (36,000lbs max TE per motor,

> > 200,000pds max TE for the unit)

> >

> > Robb Fisher

> > RFDI

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