To facilitate more non-stop expresses between Paddington and Birmingham, while maintaining an equally fast service to the principle stations on route required the introduction of slip coaches. These coaches were positioned at the rear of the express and coupled with special apparatus that allowed a Slip Guard (who rode in the slip coach) to disconnect the coach from the main portion of the train.
This slipping operation took place just prior to the desired station and the slip coach then travelled under its own momentum with the Slip Guard regulating the speed with the coach’s modified vacuum brake gear until it finally was stopped at the station.
Slip coach operation broke the fundamental safety rule that there must never be more than one train in a block section. Special identification lamps were therefore carried on the rear of both the slip coach and the main train.
In Warwickshire slip coaches were detached at Leamington, Warwick, Knowle and Hatton Junction. The majority of these services were destined for Stratford-upon-Avon; on Birmingham to Paddington trains (up) the slip coaches were detached at Hatton, the Stratford branch junction, but on Paddington to Birmingham trains (down) the slip coaches for Stratford were detached at Leamington, prior to the steep climb up Hatton Bank. This had the advantage of reducing the number of coaches that the express train had to haul up the incline.
