Hi Stewart,
I wanted to favor the color shot although I have been delighted with other B&W shots that you have posted before, but the color version has come out a bit too dark and lost some of the detail in the process. Maybe if the exposure was kicked up a bit, not only would the lost detail be revealed but also the bluish tint might be reduced. And since you are taking critiques, both the B&W and the color shots would be even better if you could have caught the loco before the trees blocked off the front of the loco - making the composition a bit less appealing than it would otherwise be. But since you have such a great set of subjects, it is hard to be so critical. And you are obviously having a great deal of fun!
Ross Schlabach