Roger and all,
Regarding wind, I had an encounter with another video company in 1991 while doing the Rotary. This cameraman had a sound guy with him, and had one of those big busy windcovers, that are called Zeppelin Windscreens I think. Anyway the cameraman told me those things were incredible and really knocked out all the wind. Well I saw their video, and it did knock out all the wind. The problem was it knocked out a lot of the steam sounds as well. For example when the engines plowed out Cumbres they were not working hard, but there were a lot of neat steamy sounds as they passed the cameras, but in the other guys video you heard Nothing!!! So there are sometimes trade-offs. I decent medium windscreen is the answer.
Cheers,
Greg
PS No wind is the best scenario, and it makes the cold morning steam and smoke hang there which is nice.