Thanks Derek that cleared it up for me. Re viaducts I supose you would not be able to build railways now but where i lived in Knaresborough in North Yorkshire there is a particularly good example of viaduct building which is constructed of stone with a castellated top and garaceful arches. Almoost any day of the week in the Summer you ,will see it being painted from many diferent anlgles and should the line become redundant I don't see it ever being pulled down.Oh and by the way I rather like wind farms to

Joe Nicholson.