Ooops Though I was never driving the train, just a mere passenger. Though I can understand the restriction. I have the same when I drive. I want one full clear day before I drive again. If you know your hours you can drink around the restrictions and still be in the clear.

my uncle got kicked of the navy for that reason, couldnt stop drinking on his days off :S
I personally don't like drinking for the sake of it or for "mingling", but it seems that's how it's done in the companies I know at least, can enjoy your colleagues company outside work without being clattered.