The Clayton Tunnel rail crash, which took place on Sunday 25 August 1861, five miles from Brighton on the south coast of England, was the worst accident of the British railway system to that time. Two trains collided inside the tunnel, killing 23 and injuring 176 passengers.
The disaster scenario actually involved three successive northbound trains on the same track, which all left Brighton station within a few minutes of one another. The signalman at the south end of the tunnel tried to stop the second train from entering the tunnel before the first one had left it, but wrongly thought his red flag had not been seen, and then misinterpreted a telegraph signal from the north end of the tunnel as referring to the second train instead of the first. Assuming that both trains had cleared the tunnel, he signalled the third one to proceed, but in fact the second train was trying to reverse out of the tunnel.
Signalman Henry Killick had an alarm bell linked to a signal, a needle telegraph and a clock in his cabin, close to the south entrance of the tunnel. He could control the signal by a wheel in the cabin, but it would normally be at "danger" unless he approved a train to enter the tunnel. When a train passed, the signal returned automatically to "danger", but if it did not, the alarm bell would ring. The telegraph was linked to the north signal box, and would show there was a train in the tunnel if the signalman at the other box activated it by pressing and holding down a switch. Otherwise the needle would hang vertically.
Except for the Clayton Tunnel, the line was worked on the time-interval system, requiring trains on the same track to be separated by 5 minutes. Despite this, the three trains actually left Brighton within 7 minutes:Portsmouth Excursion left at 8.28 am
Brighton Excursion left at 8.31 am
Brighton to Victoria left at 8.35 am
At the tunnel mouth, the first train passed the signal at "clear", but the alarm bell rang to warn Killick that it had not returned to "danger". He sent a "train in tunnel" message to Brown in the north cabin, but did not return the signal to "danger" in time to stop the second train from passing the signal and travelling to the tunnel. It was only 3 minutes behind, and may well have caught up with the first train. Realising that the first train was still in the tunnel, he rushed out of the cabin waving his red flag to stop the second train just as it was passing. He could not be sure that the driver had seen the flag, however. He telegraphed Brown "is tunnel clear?"
At that moment, the first train cleared the tunnel, so Brown signalled back "tunnel clear" to Killick. But unfortunately, Killick thought that Brown was referring to the second train and not the first. In fact the second train's driver had seen the red flag and stopped about half a mile into the tunnel, and was reversing back to return to the south end. Meanwhile, Killick saw the third train approaching and stopping at his signal; thinking that the tunnel was clear, he waved his white flag for it to proceed. The second and third trains then collided in the tunnel with great force. The second train was pushed forward, and the locomotive obliterated the guard's van at the rear before smashing into the last carriage. It then rode up over the carriage roof and smashed its chimney against the tunnel roof before stopping. Many of the 23 deaths were in this last carriage, where passengers were burnt or scalded to death by the broken engine. The bodies of a number of the victims were stored temporarily in the cellar of The Hassocks Hotel.
A nine-day inquest was held at Brighton town hall into the deaths of the 23 victims. It concluded with the jury giving a verdict of manslaughter against Charles Legg, the assistant stationmaster of Brighton station, finding him negligent by starting three trains so close together (against the rules of the company). The jury did not find any negligence by either signalmen Killick or Brown. Legg was committed for trial for manslaughter, but found not guilty.
The catastrophe publicised the problem of trains travelling too close together, with signalmen having to appraise the situation too quickly for safety's sake. A simple communication mistake between the two signal boxes caused havoc that Sunday, but the telegraph was also blamed for the tragedy because it did not register without continual pressure on the switch. The signal, too, was also at fault for not returning to "danger" immediately after the train had passed. The accident encouraged the use of the block system (rather than the time interval system) for the remainder of the railway system.
One other aspect of this accident was that Signalman Killick was working a continuous 24-hour shift that day, rather than the regulation 18 hours to gain a complete day off duty. In his report on the accident Captain Tyler stated that "it was disgraceful that a man in so responsible a position as Signalman Killick should be compelled to work for twenty-four hours at a stretch in order to earn one day of rest a week."
Charles Dickens may have partly based his story "The Signal-Man" on this accident, dramatising the events (especially the bells and the telegraph needle), as well as adding other incidents. His own experience at the Staplehurst rail crash may have inspired him to write this ghost story. Readers of the story in December 1866 would likely have still remembered the Clayton accident.
Other accidents in which the signalman forgot, or got confused about, the presence of a train include:Welwyn Tunnel rail crash – 1866
Thirsk rail crash – 1892
Hawes Junction train disaster – signalman forgets about light engines on line – 1910
Quintinshill rail crash – signalman forgets about train on line – 1915
Winwick rail crash – 1934