Of the traditional ‘slam door’ fleets only a handful of vehicles are now operated under exemption by franchised passenger operators. These include the two Class 421 three-car electrical multiple units operated on the Lymington branch line by South West Trains, and the two single-car Class 121 diesel multiple units operated by Chiltern Railways and Arriva Trains Wales on the Aylesbury—Princess Risborough and Cardiff Queen Street—Cardiff Bay routes respectively. All are fitted with central door locking.
In addition, though not ‘slam door’ stock, there are currently around 1200 locomotive hauled coaches used in passenger service by franchised passenger operators. The majority of these coaches have hinged doors which are opened and closed manually at stops and central door locking operated by the guard. The exception is Mark 4 coaches which comprise around 260 of this total and have power operated sliding doors.