Horseshoe curve - Upgrade Stack train with pushers 

I visited Horseshoe curve, and took a video looking "out" the horseshoe of this upgrade double-stack train.
Few things to note. At about 1:40 into the video, you can see a 2nd intermodal train, also heading upgrade, on track 2. That train is shorter and moving slightly faster. This second train is also visible at about 2:40, when the train in front has only single stacks. The 2nd train seems to end about 3:45 in.
Also, the double-stack has 2 pushers on the tail end. This is the first train I had ever seen with pusher units. 7 units total.