Mark 1 rolling stock means a series of vehicle types, including both electric and diesel multiple units and locomotive-hauled vehicles, built mainly in the 1960s and 1970s, which share certain construction characteristics.
The operation of unmodified Mark 1 rolling stock was prohibited under the Railway Safety Regulations 1999 because of poor crashworthiness and other safety issues and the fleet was gradually withdrawn from use on the network by the end of November 2005.
Someone wanting to operate this rolling stock may apply for an exemption from the 1999 regulations which may be granted subject to certain modifications being made to reduce safety risks. A list of current exemptions and how to apply for one is available.
Issues with Mark 1 rolling stock
Mark 1 rolling stock is often referred to as 'slam-door trains'. These vehicles have a poor safety record and are likely to suffer far more damage in a collision with potentially harmful consequences for passengers because although they have a robust chassis, the body shell is relatively weak. Also over the years there were many fatalities and injuries connected with the slam doors, mainly due to the lack of central door locking and partly due to the pull down windows in doors.
When Mark1 rolling stock was more widely used before unmodified vehicles were completely withdrawn, safety risks were reduced by the Installation of train protection and warning systems (TPWS) on the railway and the fitting bars across windows. However in general, risks decreased as Mark 1 rolling stock was withdrawn from operation.
Current use of Mark 1 rolling stock
Heritage/charter train companies, and other operators of Mark I rolling stock, have applied for exemptions to allow them to continue to run stock without central door locking, subject to certain conditions. Most of these exemptions have been granted until 31 March 2023.
Although the provisions of the Railway Safety Regulations 1999 relating to Mark I have achieved the desired outcome, they have an ongoing effect while the exemptions made under the regulations are still in force.