UP’s Big Boy Stand Alone PTC

[JBaxter]

https://railfan.com/big-boy-4014-runs-o ... tc-system/

It looks like the test run of the big boy the other day was to test out the new ptc system installed. Possibly allowing for the big boy to run without a trailing diesel if UP allows it

[SD80MAC]

It can, but I would bet it won't, other than on short runs. The UP Steam Crew has stated numerous times that the diesel (in this case, the usual SD70M #4015) will always be tagging along. The diesel helps stretch out the Big Boy's fuel and water supply by helping out with the load. They also use it for dynamic braking, which saves wear on the expensive brake shoes that the UP passenger fleet uses. But yes, 4014 will now no longer need to use Leap PTC via the trailing diesel.