I was on that train; and whatever was leading wasn't able to do more than about 69 m/h, explaining why we kept losing more and more time: It departed CHI 58 minutes late, arrived GBB 1 hour, 18 minutes late, OMA 2 hours, 9 minutes late, and DEN 3 hours, 26 minutes late (although I don't blame the engine for all of the latter)..
The Galesburg agent where I boarded said that the late departure from Chicago was due to adding the ski train cars. I assumed that “make them wait” Amtrak had waited until departure time to connect the extra cars. But watching the snafu in Denver from the rear of the last sleeper, I'm not sure that it didn't take an hour longer than planned to add the cars.
The procedure in Denver was to take the wye as usual and back into the station, except this time onto the ski train track next to the Zephyr's. Then disconnect the ski train, pull forward, then back onto the usual track. But they seemed to have trouble disconnecting the cars, until one of the employees was heard calling for a manual. Once the cars were finally disconnected, an employee came to the back of the now much shorter train with that hose apparatus. But he forgot to get the key to open the door and had to go back towards the front of the train to find the conductor, who eventually came with the key. But the conductor couldn't seem to get the key to work. Finally, they got the door open and let out a blast of air. But the conductor wasn't satisfied and went back toward the front of the train. Later, he came back, let out another blast of air, and we began backing up. But when we were on the CZ track and ready to pull into the station, there was a red light blocking our way. The conductor called someone mentioning a “restriction”; and after a while we pulled in.
I've said for a long time that switching cars is a combination of brain surgery and rocket science. Blue lights usually get blamed. But I couldn't see any blue lights.