It’s worse than that - he wasn’t being lazy, he was convinced that if he came out of the tunnel, the rain would ruin his paint. Even after it stopped raining, he still wouldn’t come out just in case it started raining again.

Basically he had a mental illness, and his punishment was to be bricked up and forced to watch the other trains going past. One is friendly, one says it serves him right. Because he has no steam, he’s unable to communicate. And all the time his paint is slowly getting ruined anyway because he’s stuck in the tunnel.

As someone who’s had a breakdown, it really resonates in a different way than it did when I was a kid.