Even though Montana Rail Link EMD SD70ACe is just seven years old in this image, it is having its prime mover changed out with a new one from Electro-Motive Diesel. A new 4,300 horsepower EMD 16-710G3C is being installed inside MRL No. 4307 at MRL’s Livingston, Montana, shop on May 7, 2012. Hard use in helper service, in addition to extreme temperature differences during cold Montana winters and very hot Mullan Tunnel operating temperatures, surely exacerbated engine wear. Recent tunnel clearance rehabilitations have mostly eliminated the extreme temperature problems, so the SD70ACe locomotive fleet will likely get more milage on these new prime movers.
