Later on, in my life as a BR goods guard, tea and butties were often as not taken on the hoof. An enamel brew can essential to any movable feast. Though the mess room, brew hut and brake van, provided some rude shelter, heat and hot water.
These images from the Museum of Transport - Greater Manchester http://www.gmts.co.uk mark and record that great institution the bus canteen and the lives of working people.
Never leave home without the makings of a brew, what's in your brew can?