1.- I went for a walk along the railroad tracks, but then I suddenly felt run down.

2.- I used to be a railway engineer but I kept losing my train of thought and going down the wrong track.

3.- A young man has just told me about a great offer on railway buffers.  Apparently, it's an end of line sale.

4.- I like to share a train pun or one-liner.  I've always been driven by the joy of monorails.

5.- Well, one thing I'll say about ticket inspectors is that you've certainly got to hand it to them.

One bonus joke ;)

6.- Anyone who steals a train would definitely have a locomotive.