BNSF Railway announced this week that the years-long effort to install Positive Train Control along the former Montana Rail Link is nearly complete. Activation of PTC, which could happen as soon as this week, is expected to bring about several significant changes along the route. 

Long before BNSF took back control of the former Northern Pacific across southern Montana, MRL was working to install Positive Train Control on the route. The regional railroad announced its plans to install PTC in 2018, making it one of the first railroads in the country to voluntarily implement this collision-prevention technology. That effort has only advanced with the BNSF takeover in 2024, and for a time, the most obvious “victims” of the modernization were the steam-era NP searchlight signals. But now, as BNSF prepares to activate the system, it seems there will be another casualty — blue MRL locomotives leading trains. 

Once PTC is turned on, none of the MRL units will be able to lead trains at track speed on the former MRL main line. This means the remaining MRL units will likely be relegated to trailing status or to yard and helper service. 

As of early fall, blue units could still often be found on locals and switch jobs, but that was likely to change. It was also unclear how much work the blue units would find in the yards. In Missoula, for example, switch jobs often venture beyond yard limits to switch industries in Bonner and DeSmet, both of which require main line running. 

While MRL’s “blue pullers” were likely to be relegated to trailing status on home rails, many of the railroad’s SD70ACe locomotives are still putting on the miles across the BNSF system, from California to Chicago, albeit usually behind BNSF power. In mid-October, at least four units were spotted in the Denver area.

—Justin Franz