Up or down the line briefcase

Travelling Post Office (TPO) was a series of one or more rail carriages in which the manual sorting of letters took place. These carriages were invented to save time sorting mail while it was being transported to its destination. This brown leather TPO briefcase has handwritten on the reverse of the case in white 'DN/UP/ SPL TPO/ TPO NO/ 2 SIDE'. Routes were marked as either 'up' or 'down' depending on their direction of travel. The 'up' line headed towards London while the 'down' line headed away.