How and when has CN limited run through power from BNSF and UP?

Sometime in the past 3 years CN-GTW mainfest trains have stopped using run through power.

For years on the CN-GTW mainline from Chicago to Detroit or Port Huron there has been run through power on many of the mainfest trains from CNW, UP, CSX, NS, ATSF, BN, BNSF, SOO/CP, KCS.

Now the only run through diesel locomotives are on Auto Carrier and coal unit trains from the BNSF and UP.

How and when did the Management at CN come up with a program to limit run through of loco power from BNSF and UP to just unit trains?

Andrew Falconer

Without knowing any particulars - CN may be paying back a Horsepower Hour deficit with UP and BNSF … thus CN power working more on BNSF & UP than the foreign power working on CN.

I think that most carload trains are now running via Kirk Yd. (former EJ&E) when the western power is being changed out.

Then I have to find Kirk Yard on the map of Chicago area railyards.

The combined CN-IC-BC Rail-EJ&E fleet is now what is circulating on the CN-GTW mainline in Michigan.

The managment must really be getting a lot of pressure from somewhere to cut back on foreign power so abruptly. I guess the ecomomic slowdown of 2009 and the EJ&E merger helped swiften the change in motive power operations. There had to have been a cut-off date sometime between 2007-2010.

Andrew