Awesome vid, I've never seen a DPU in 'mid point' here in the Seattle area either, great catch! I wonder if the there in the middle because the train is breaking into two at some point?
Well, the general reason railroads use DPUs is they reduce stress on the couplers (less chance of breaking one) and I believe they also reduce fuel consumption compared to having all the locos at the head of the train. The Stevens Pass route is fairly steep, with some parts at a 2.2% grade. That's pretty steep for trains. I'm guessing that the mid-train DPUs are used here to lessen the change of coupler breakage. For those unfamiliar with the terminology, DPU stands for Distributed Power Unit and are the locos in the middle or reart of the train. The DPUs are radio controlled from the lead loco. Google "Distributed Power Unit" for more info. A "2.2% grade" means 2.2 feet of rise per 100 feet of track. Generally 1-1.5% is considered steep. 2.2% is close to the maximum a Class 1 railroad will want on a mainline track. Steep grades cost money to climb!
Appreciate the explanation for the covered gons. Keep up the great videos!
Great catch Sir!
Cheers Gregg
Mid DPUs are actually pretty common on some southbound CN manifest trains out of Winnipeg going towards Chicago.
Thanks Todd...
Awesome vid, I've never seen a DPU in 'mid point' here in the Seattle area either, great catch! I wonder if the there in the middle because the train is breaking into two at some point?
Well, the general reason railroads use DPUs is they reduce stress on the couplers (less chance of breaking one) and I believe they also reduce fuel consumption compared to having all the locos at the head of the train.
The Stevens Pass route is fairly steep, with some parts at a 2.2% grade. That's pretty steep for trains. I'm guessing that the mid-train DPUs are used here to lessen the change of coupler breakage.
For those unfamiliar with the terminology, DPU stands for Distributed Power Unit and are the locos in the middle or reart of the train. The DPUs are radio controlled from the lead loco. Google "Distributed Power Unit" for more info.
A "2.2% grade" means 2.2 feet of rise per 100 feet of track. Generally 1-1.5% is considered steep. 2.2% is close to the maximum a Class 1 railroad will want on a mainline track. Steep grades cost money to climb!
Is this train routed over Stevens pass?
Yes. It's traveling southbound past my location south of Delta Yard. Just south me of the tracks turn eastward towards the pass.
what day was this filmed?
July 11th
I thought so! I saw this train up in Skykomish that day. the UP engine surprised me, but then Mid Train DPUs surprised me even more!