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PapersEffect of station design on death in the London Underground: observational study
T J Coats a St Bartholomew's and the
Royal London School of Medicine, Royal London Hospital, London E1 1BB, b London Helicopter Emergency Medical Service, Royal London
Hospital
Correspondence to: Mr Coats
t.j.coats{at}mds.qmw.ac.uk
Injury and death after a fall or jump under a train (known
colloquially as a "one under") are common on the London
Underground.1 Emergency teams noticed that both severity
of injury and survival seemed to be related to the design of the
station, with a drainage pit (often called the "suicide pit")
giving a protective effect. This pit is located under the railway
tracks for the length of the platform in about half of underground
stations. It is usually about a metre deep and was originally intended
to drain water away from the platform.
We carried out this study to assess mortality in patients hit by London
Underground trains at platforms with and without a drainage pit.
For each incident from January 1996 to March 1997 the "record of
incident" made in compliance with the Railway Regulations Act of 1893 was retrospectively examined. The platform of each incident and the
outcome (lived or died) were recorded. The presence of a drainage pit
was ascertained from the station manager or by personal inspection. The
outcome with and without a drainage pit was compared with Fisher's
exact test.
Fifty eight cases occurred over the 15 months, but the exact platform
concerned could not be ascertained for five incidents. Thirty three
patients died (overall mortality 57%). The table shows that the
mortality was 44% for platforms with a pit compared with 76% for
platforms without a pit. This difference was significant (P=0.026).
This study shows that the presence of a pit halves the number of
deaths in patients who are hit by a train. The overall mortality (at
57%) was similar to the previously reported figures of
55%2 and 45%.1 Many attempts have been made
to reduce the number of deaths on the London
Underground.3-5 The association between the pit and
increased survival2 is purely fortuitous as pits were
introduced for engineering reasons. The pit increases the clearance
between the train and the ground, probably allowing a casualty to fall
away from the train's wheels. Even when a pit is present, if the
casualty has not fallen into it then he or she is unlikely to survive.
In the design of rolling stock little attention is paid to the
interaction between a human body and the train. New carriages at
present being introduced on the Jubilee line have less ground clearance, and therefore there is even less room for a body to escape
the wheels. The ultimate method of preventing death under trains is the
complete separation of moving trains and passengers by the introduction
of sliding doors along the platform edge that open only when the train
has come to a halt. This feature has been incorporated into some new
stations but would probably be prohibitively expensive to introduce at
existing stations.
Being hit by a train is an important cause of death from trauma in
London, but the presence of a pit under the rails halves the mortality.
The mechanics of the interaction of the human body with the train are
poorly studied, and so present rolling stock and stations are not
designed to maximise survival.
Contributors: TJC initiated the study, helped develop the method, analysed the data, and cowrote the paper. He is the guarantor of the paper. DPW helped develop the method, collected the data, and cowrote the paper.
Funding: None.
Competing interests: None declared.
(Accepted 29 July 1999)
© BMJ 1999 Related Article
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