Slam-door train

A slam-door train or slammer is a set of diesel multiple units (DMUs) or electric multiple units (EMUs) that were made before the creation of automatic doors on railway carriages in the United Kingdom and other countries, which have manually operated doors. The name came about because of the noise made by the passengers slamming the doors closed when the train was about to depart.
Some slam-door trains had doors that could only be opened from the outside, so passengers had to lean out of the window to reach the outside door handle.
In 2005, all slam-door trains were replaced with trains with automatic operated doors.