What is Dash-3?

Question

Some locomotives have the designation of -3 (Dash 3), what is this, improved electronics?

Answer 1

I have not heard of "dash 3" but i know that there are "dash 7, 8, and 9"

where it comes from is the locomotive model.

For example GE locomotive C44-9W is:

C= six axle

44= hundreds of HP

-9 is the decade it was built in (in the 1990's).. this

    is where "dash 9" comes from

W is the wide bode style

Answer 2

"Dash-3" is not an official EMD designation, but they are used for rebuilds of EMD engines.

Norfolk & Southern for instance had been rebuilding their troublesome GP50s into "GP38-3's".  It involves de-rating the power plant to lower horsepower output, removing the turbocharger, adding a paper filter box, and rebuilding the radiator section to just 2 fans (vs. 3 on the GP50).

NS couldn't call the rebuilds GP38-2s even though they have similar power and running characteristics to GP38-2s, because under the hood there are too many differences (for instance, spare parts for GP38-2s might not be compatible with these).  So to avoid confusion, they call these GP50 rebuilds "GP38-3s".

Here are some nice photos of an NS former GP50 rebuilt to a GP38-3:  http://www.rrpicturearchives.net/locoPic...

Hope this helps.

Answer 3

My understanding is that the Dash 3 designation also qualified the unit differently under the EPA's Tier-1 (-2 & -3) Emission regulations.  Many of the older EMD 645's had some issues with meeting compliance so rebuilding them and performing modifications was a work around for this.

I've heard that UP is considering re-powering a number of their SD40-2 fleet with newer 12-710 series engines when they come due for rebuild.  This means they aren't true SD40-2's any more but the power from the 12-710's would be comparable to the older 16-645 prime movers.  I've heard they will be designated as SD40-3R's or similar.