Yesterday morning I got called for a Q train to Barstow. On duty time was 3:43 am. It started out as a good trip. I had a female engineer. Then they stopped us a few times. We were at the Barstow signal and they said they were going to "flip" us (send us back to Needles in a van) but we said that we had less than two hours left, so they scrubbed that idea. When I got to the hotel I had a big burrito and went to bed. I wok up after 4 hours and couldn't get back to sleep. I took some sleeping pills and slept until I got my call at 1:12 am. I was called for the "H BARGAL." My cell phone said that it was raining. I as glad that these days the yard crews put the H trains together. I went outside and it wasn't raining, but it was cold. I got down to the depot and the trainmaster told me that there were no yad crews and we would have to put the train together. I told my engineer that when he sowed up and he said something that I can't print. I found out that our cars were all in D5, and we would just have to hook the power on the head end. Our power was on Ready One, as close to the depot as it could be, so it was a short walk. We had 4 motors, and the leader was facing the right way. We were lined out so I didn't have to get down and line any switches. Also, a van had been assigned to help us. This was shaping up to be a good day- or so I thought. We used D1 as a runner. When we were over the switch I shoved my engineer back to a hook. I laced the hoses. There were no brakes on the head end. I got in the van and went to the rear of the train, checking my cars. We had 3 "strangers" (cars that we weren't supposed t have). I reported it to the Bowl Tower. I head somebody say, "Who put that train together?" Over the radio. The bowl tower said that two of the cars, both tankers, would have to be set out. I went to the rear of the train, hooked up the ETD (I had a hard time with it), did the Class III, and released three handbrakes at the rear of the train. I went to the "strangers, tied 3 brakes behind them and made the cut. The Bowel Tower told us to set the cars in the "South Track." i didn't know where that was but my van driver did. She took me here. There as a North Track and a South Track. There were two motors in the North Track. The derail was up. There was one hopper in the South Track. The van driver told me to drop the derail to the South Track. So did the Bowl Tower. But they didn't tell me anything else. I had my engineer pull the last car over the switch. The Bowl Tower threw the switch. I positioned myself near the hopper, and intended to make a hook there. I started my engineer back. After a few seconds I saw, to my horror, that the cars were going into the North Track. I told my engineer "stop" twice, but by the time he stopped the first car had gone over he derail and one truck went over the derail. I notified the Bowl Tower. I noticed that there was a hand throw switch that separated the North Track from the South Track. Nobody had told me that. I was unfamiliar with this part of the yard. A carman came out and said that it would be easy to get those tow cars back on the track. The superintendant. came out and talked to me. I had never met him before and he said he had never heard my name before and that was a good thing. I said, "The only cars that derailed are the ones that we were supposed to set out. The rest of our train is on the track. If it's okay I would like to make the cut, put our train back together, and leave." He asked me if I felt okay doing that and I said, "Sure." I got an "in between." closed the angel cock ,and made the cut. I had my engineer pull over the switch. When the Bowel Tower threw it I shoved him back to our train. I could not make the hook. The couplers were not aligned. I called for a carman. One of them showed up very quickly and lined one coupler for me. He gave me a tool to line the other one up. I lined it, then guided my engineer back to a hook. I laced the hoses, released the brakes, and had the van run me up to the head end. We were finally ready to go and departed after being on duty for 4 hours. As we got closer to Needles my IPAD said that we were to set out the 4th motor. When we were stopped outside of Needles my engineer got on the radio and said, "That motor had a bad air compressor. We will have to use another motor to set it out because the brakes don't work. Also, one of the motors had bad dynos, so if you set out one motor the outbound will only had 16 dynamic brakes. They highballed the set out. When we got we each had to write a statement about what happened. My engineer said, "All the times I put cars o the ground before I got a van ride home, but not today. " I found out that the cars that I had put on the ground were already yarded. When I got home I spoke to my union rep. He said that since they let us finish the job and didn't pull us from service and give us a drug test they were probably going to go easy on me. 7 years with the railroad and I have never put cars on the ground before. My union rep said that in 25 years he has put cars on the ground several times. It happens. So, I will see what happens. I'm not worried about it. I have included a picture of our leader, the 8073.