This is my first service outside of training for the -8. First time I attempted it, I had the -8 lead and an SD40 trail. Not enough power to get up the grade. By the time I got to Hyndman and dropped to 25mph, I had a continual drop in speed while at max power. Decided to quite and try again. Second time, I got an AC4400 as my trail. Thinking....cool, this should work. Only slightly. As I slowed to 25mph past Hyndman, my speed continued to drop to about 17-18mph. Barely holding on. At max power. If I had to stop, I would not get the train moving again. Could this be due to Banking Comm not being functional? Should not matter if second engine is connected to first I thought. Could not imagine if this was real that a train would be setup that could not handle the load up the grade and have the power to stop if necessary and then continue on.