Division 4.2.2.6.1 Minimum requirements of the braking systemF1
United Kingdom
All vehicles in a train must be connected to the continuous automatic braking system as defined in the RST TSI.
The first and last vehicles (including any traction units) in any train must have the automatic brake operative.
In the case of a train becoming accidentally divided into two parts, both sets of detached vehicles must come automatically to a stand as a result of a maximum application of the brake.