The Seer Green rail crash occurred on the morning of 11 December 1981 near Seer Green,

Buckinghamshire Buckinghamshire (), abbreviated Bucks, is a ceremonial county in South East England that borders Greater London to the south-east, Berkshire to the south, Oxfordshire to the west, Northamptonshire to the north, Bedfordshire to the north-e ...

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe ...

between two four-car Class 115

diesel multiple unit A diesel multiple unit or DMU is a multiple-unit train powered by on-board diesel engines. A DMU requires no separate locomotive, as the engines are incorporated into one or more of the carriages. Diesel-powered single-unit railcars are also ...

s, killing one driver and three passengers.

Events

In the

winter Winter is the coldest season of the year in polar and temperate climates. It occurs after autumn and before spring. The tilt of Earth's axis causes seasons; winter occurs when a hemisphere is oriented away from the Sun. Different cultur ...

of 1981, the

weather Weather is the state of the atmosphere, describing for example the degree to which it is hot or cold, wet or dry, calm or stormy, clear or cloudy. On Earth, most weather phenomena occur in the lowest layer of the planet's atmosphere, the ...

in Southern England turned cold and there were frequent heavy falls of

snow Snow comprises individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes. It consists of frozen crystalline water throughou ...

. On the

Chiltern Main Line The Chiltern Main Line is a railway line which links London () and Birmingham ( Moor Street and Snow Hill), the United Kingdom's two largest cities, by a route via High Wycombe, Bicester, Banbury, Leamington Spa and Solihull. It is one of ...

, the snow caused tree branches in the cutting at Seer Green to be weighed down and some of them were brushed by passing trains. On 11 December, the driver of an empty train from

Marylebone Marylebone (usually , also , ) is a district in the West End of London, in the City of Westminster. Oxford Street, Europe's busiest shopping street, forms its southern boundary. An ancient parish and latterly a metropolitan borough, it ...

Princes Risborough Princes Risborough () is a market town in Buckinghamshire, England, about south of Aylesbury and north west of High Wycombe. It lies at the foot of the Chiltern Hills, at the north end of a gap or pass through the Chilterns, the south end o ...

came across a fallen branch lying across the track. He telephoned the

signalman A signalman is a person who historically made signals using flags and light. In modern times, the role of signalmen has evolved and now usually uses electronic communication equipment. Signalmen usually work in rail transport networks, armed for ...

High Wycombe High Wycombe, often referred to as Wycombe ( ), is a market town in Buckinghamshire, England. Lying in the valley of the River Wye, Buckinghamshire, River Wye surrounded by the Chiltern Hills, it is west-northwest of Charing Cross in London, ...

to tell him that he was going to clear the obstruction and would be delayed by a few minutes. Meanwhile, at Gerrards Cross, behind the stationary train, the driver of the 07:31 from Marylebone to

Banbury Banbury is a historic market town on the River Cherwell in Oxfordshire, South East England. It had a population of 54,335 at the 2021 Census. Banbury is a significant commercial and retail centre for the surrounding area of north Oxfordshir ...

was being cautioned by the signalman about the overhanging branches. The signalman then attempted to clear the starting signal for the train to proceed but the lever was locked. Unaware that the empty train had stopped, he looked at his

signal box In signal processing, a signal is a function that conveys information about a phenomenon. Any quantity that can vary over space or time can be used as a signal to share messages between observers. The '' IEEE Transactions on Signal Processing' ...

diagram and thought that the indications showed that the empty train was running towards

Beaconsfield Beaconsfield ( ) is a market town and civil parish within the unitary authority of Buckinghamshire, England, west-northwest of central London and south-southeast of Aylesbury. Three other towns are within : Gerrards Cross, Amersham and High W ...

. Assuming that the signal lever had frozen (when in fact it was electrically locked by the stationary train), he authorised the driver to pass the signal at danger, and the train set off into the still-falling snow. Glancing again at his diagram, he saw that the lights towards Beaconsfield were not in fact lit, and realised that the empty train was still in the section near Seer Green. He quickly went to the window and tried to attract the driver's attention by shouting, but nobody heard him. The driver of the Banbury train drove too fast for the conditions and ran into the back of the empty train at about 30 mph. The front coach of the Banbury train partly telescoped underneath the rear coach of the empty train, and the driver and three passengers were killed. Five others were also injured.

Investigation

At the

public inquiry A tribunal of inquiry is an official review of events or actions ordered by a government body. In many common law countries, such as the United Kingdom, Ireland, Australia and Canada, such a public inquiry differs from a royal commission in that ...

, Inspecting Officer

Major Major ( commandant in certain jurisdictions) is a military rank of commissioned officer status, with corresponding ranks existing in many military forces throughout the world. When used unhyphenated and in conjunction with no other indicato ...

C.F. Rose held the signalman at Gerrards Cross chiefly to blame, although he did note that the signalman had only been qualified for a month and had been appointed through a job centre because nobody could be recruited internally. In addition to his inexperience, the signalling between Gerrards Cross and High Wycombe was unusually complex, with several

track circuit A track circuit is an electrical device used to prove the absence of a train on rail tracks to signallers and control relevant signals. An alternative to track circuits are axle counters. Principles and operation The basic principle behind ...

block sections and intermediate block sections. The signal box diagram was subsequently altered to make its indications less ambiguous. The driver of the Banbury train also shared some responsibility, because he drove too fast to be able to stop short of the stationary train. Although

British Rail British Railways (BR), which from 1965 traded as British Rail, was a state-owned company that operated most of the overground rail transport in Great Britain from 1948 to 1997. It was formed from the nationalisation of the Big Four (British ra ...

's rules stated that the guard of the empty train should have applied

detonator A detonator, frequently a blasting cap, is a device used to trigger an explosive device. Detonators can be chemically, mechanically, or electrically initiated, the last two being the most common. The commercial use of explosives uses electr ...

protection, this would have been unreasonable given that the obstruction would have been cleared in a few minutes.

References

* {{Transport in Buckinghamshire Railway accidents and incidents in Buckinghamshire History of Buckinghamshire 1981 in England Railway accidents in 1981 20th century in Buckinghamshire Train collisions in England Railway accidents caused by signaller's error 1981 disasters in the United Kingdom