Lewisham, London, UK, 1957 – a simple collision escalates into a serious disaster. The combination of a dark winter evening, signals missed, thick fog, trains running out of timetable and the collapse of a heavy girder bridge resulted in the worst ever accident on the Southern Region of British railways.

Fog Disrupts Service

Wednesday, 4 December, 1957: the fog had been hanging round the Thames basin. By dusk it had thickened and visibility extended to no more than 10 to 15 yards.

The eastern section of the Southern Region was badly affected by the weather and trains running from Cannon Street and Charing Cross were running late and out of order. The lines from both of these stations combined into a complex track layout as they approached London Bridge and by New Cross Station there were only four lines.

• The 5.05pm Cannon Street to Hastings train hauled by a Schools Class 4-4-0 steam engine had left Cannon Street 38 minutes late. As the train passed the signals, the driver was having trouble finding the colour lights of the signals, due to the dense fog. The fireman of the 5.05 commented that the lights of the signals could barely be seen from 20 yards. The signals were on the right hand side of the track and the driving side of steam trains in the Southern Region was on the left, so drivers' views of signals were obscured by the boilers of the engine they were driving.

• Three minutes behind the 5.05 was the 5.16pm Cannon Street to Orpington electric train. The driver of the electric train had an unobscured view of the signals, but still had difficulty seeing the lights of the signals as the fog was so thick.

• A few minutes behind was the 5.25pm Charing Cross to Hastings train, pulled by a diesel-electric unit with the driver right at the front as with the electric. The train was stopped by a red light at Parks Bridge.

This set the scene for the drama which followed.

The Signalling System

The signals at St John's were controlled from the signal box near the station, although a lever could not be pulled if a train was on the section of the line beyond that signal.

Many of the signals not controlling junctions were automatic and not worked by levers. The next signal box was Parks Bridge Junction which controlled the local and through trains and also a connection to the Mid Kent branch to Hayes.

Trains were not offered and accepted, as in manual block working, but were simply described on the train describer¹. These clockwork instruments consisted of a clock face with a pointer towards up to 12 descriptions around the face and levers operated by the signalman to identify trains to the next signal box down the line. There were two describers for each track, one to say what type of train was coming and one to say where it was going.

The Signalman's Confusion

The signalman at Parks Bridge could not identify the Charing Cross-Hastings train, nor could he determine where it was going; he thought that the train was an electric train for the Mid Kent line which branched off to the right.

The signalman could not clear the signals to the Mid Kent line because he already had a train coming on the up through line from Bromley North and also another heading down the Mid Kent line from Lewisham Station. The driver of the Charing Cross-Hastings train telephoned the signalman to identify his train, but the signalman did not know which signal the driver was phoning from.

In the meantime, the 5.18pm Charing Cross to Hayes, which had left Charing Cross 30 minutes late, three minutes behind the diesel, approached St John's. This was the electric train the signalman at Parks Bridge had mistaken the diesel for. The driver of the electric drew to a halt at a signal showing red behind the diesel. The back of the 5.18 was on the curve just beyond the Nunhead to Lewisham overbridge.

The 4.56pm steam train from Cannon Street to Ramsgate, hauled by a Battle of Britain class 4-6-2 No 34066 Spitfire, had been badly delayed on the empty run from the sidings to Rotherhithe Road. It did not leave Cannon Street until 6.08pm and had green signals as far as New Cross. The next three signals, all on the right of the line, were at double yellow², single yellow and red, the red being at the country end of St John's Station.

The driver of the delayed 4.56 was on the left hand side of the cab and the fireman was on the right hand side calling out the colour of the signals. After the green at New Cross, the fireman went back to his duties, assuming that the driver would see the next two signals. Though the driver was on the left hand side, they were on a left hand curve and in clear weather the signals could be seen in spite of the restricted view caused by the boiler. Neither the driver nor fireman thought that the fog would be as thick as it was. It was never established whether the driver saw the next two signals or not.

Disaster Strikes

The next thing the driver saw was the station lights at St John's. The driver called out to the fireman to watch for the signal, and just at that moment the fireman saw the red glow of the signal at the end of the platform. The fireman called out to the driver who applied the brakes, but it was too late because 138 yards ahead of the signal was the 5.18 train with its brakes hard on. The 4.56 was travelling at around 30mph; the brakes had barely had the chance to move when the 4.56 ploughed into the back of the 5.18.

The force of the collision forced the rear two coaches forward and on top of the coach third from the back, destroying it. The sudden stop of the 4.56 caused the first coach to jump to the left, forcing the tender up into the supports of the flyover above. Within seconds, 350 tons of steel bridge collapsed onto the leading coaches of the 4.56. What remained of the first coach was crushed by the bridge, as was the entire second coach and the leading part of the third. The death toll was 90 and another 100 people were injured.

The disaster could have been worse as a few minutes later another train, the 5.22pm Holborn Viaduct to Dartford train, approached the flyover; fortunately it was travelling slowly and stopped in time.

The Driver's Shock

The driver and fireman of the 4.56 survived, but the driver was in a severe state of shock. What signals he saw will never be known. At first he said he had seen the yellow signals; he then denied having seen the signals at all. The fireman had not looked for the signals, since he thought the driver had seen them and had not realised that the fog would be so thick.

The driver was tried on a charge of manslaughter, but the jury could not agree a verdict. A second trial was ordered and he was found not guilty.

The Investigation

What Went Wrong?

The inspecting officer who chaired the inquiry placed the blame solely on the driver of the 4.56. He concluded that the driver did not see the two signals at caution and the red at St John's and did not apply the brake until the fireman called out that the signal was red.

The fireman's actions were not criticised.

The signalman at Parks Bridge, who stopped the 5.25 train thinking it was the train for the Mid Kent line, was not criticised for his actions.

Action taken

As with many inquiries at this period into accidents caused by drivers passing signals at danger, the inspecting officer recommended the adoption of the warning type of automatic train control, today called Automatic Warning System (AWS).