No problem. :)
Also, while it is a somewhat rare thing for a horse to encounter, if there is somewhere near where you are that has regularly used train tracks and you can ride near them that's always good to desensitize them to. At an event I used to compete at in Texas they had consistently used train tracks right on the other side of the fence that ran along a good deal of the cross country course. I can't count the number of horses that were doing super on cross country until a train came by. While, like I said, it's not something you would necessarily encounter a lot, it's just one more thing to check off your list! StormyBlues can probably attest to the train thing, since I think she's competed at the same place I mentioned.