The Slough rail accident happened on 16 June 1900 at Slough railway station on the Great Western Main Line when an express train from London Paddington to Falmouth Docks ran through two sets of signals at danger, and collided with a local train heading for Windsor & Eton Central.

It was held there for longer than usual; tickets for Windsor trains had to be collected at Slough[5] and there were many more passengers than normal.

The driver of the 13:15 Falmouth express passed Dolphin box at full speed, ignoring the distant and home signals.

The two rear carriages were "completely destroyed", "the last but one being thrown up to the roof of the station and falling back on to the engine of the second train".

The death toll would have been far higher had most of the 450 passengers on board not managed to jump clear in response to the shouted warnings.

In addition the brakes of the standing train had been released in preparation for its imminent departure, so the shock of the collision was lessened.

The enquiry ruled that a primary cause of the accident was the poor physical condition of the driver, due to his age (59 years) and fatigue; he had started duty at 05:00 that morning.

The guard claimed that he was too busy attending to luggage and mailbags to look out for signals; his priorities were supported by the officers of the company but the enquiry pointed out that according to the regulations the "safe working of the train" should have been his first consideration.

As a result of this accident the Great Western Railway worked to introduce by 1908 a system of Automatic Train Control in which a horn was sounded on the footplate when a Distant signal was passed at caution.

However, the findings of the accident enquiry dented this pride and the company immediately started experiments into improved vacuum braking systems.