Slow train on the Rideau Canal

We made it out on the ice yesterday. Henry enjoyed towing Dexter in his sled and pretending they were a train. You can't quite make out what he's saying in this video, but basically he's setting up the train scenario, then yelling "Biff! Biff! Biff!" because the cars are "biffing buffers", a term he picked up from Thomas the Tank Engine. Dexter, as usual, is going along with whatever is going on.

I have no idea why Tom is neighing.