The E-signal (

Swedish Swedish or ' may refer to: Anything from or related to Sweden, a country in Northern Europe. Or, specifically: * Swedish language, a North Germanic language spoken primarily in Sweden and Finland ** Swedish alphabet, the official alphabet used by ...

: ''Ägovägssignal'', lit. "owner's road signal") is a type of

level crossing signals Level crossing signals are the electronic warning devices for road vehicles at railroad level crossings. The basic signal consists of flashing red lights, a crossbuck and a bell (either a real bell or a speaker that mimics a bell sound), attach ...

used in

Sweden Sweden, formally the Kingdom of Sweden,The United Nations Group of Experts on Geographical Names states that the country's formal name is the Kingdom of SwedenUNGEGN World Geographical Names, Sweden./ref> is a Nordic country located on ...

on very low-traffic roads crossing a

railroad track A railway track (British English and UIC terminology) or railroad track (American English), also known as permanent way or simply track, is the structure on a railway or railroad consisting of the rails, fasteners, railroad ties (sleepers, ...

, when the same landowner owns the property on both sides of the railway track and only a few residential buildings and no facility of public interest can be reached from the road. An e-signal operates in the opposite fashion of a conventional grade crossing signal: it is lit when no train is approaching the crossing, and when a train approaches, it extinguishes approximately 30-60 seconds before the train's arrival. This is intended to provide a 'fail safe' function, in the event the power has failed or the signal bulb has blown; e-signal mountings are always supplemented with an information plate indicating the function of the signal. It is supplied from the

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 t ...

which supply a voltage to one rail in order to detect trains. When there is a train there can be no voltage difference between the rails. This means that no external

uninterruptible power supply An uninterruptible power supply or uninterruptible power source (UPS) is an electrical apparatus that provides emergency power to a load when the input power source or mains power fails. A UPS differs from an auxiliary or emergency power system ...

is needed and the installation cost is greatly reduced, allowing many more to be installed within limited budgets. Due to its method of function, the e-signal is considered to be potentially confusing to drivers and is being phased out of service; however, in Sweden there are still approximately 170 E-signals in operation (value from 2010). Also gateless crossings are not allowed to be installed. Full gate installations are now needed when new crossings are built or existing crossings get signalling.

United States

The

Monon Railroad The Monon Railroad , also known as the Chicago, Indianapolis, and Louisville Railway from 1897 to 1971, was an American railroad that operated almost entirely within the state of Indiana. The Monon was merged into the Louisville and Nashville Ra ...

used a similar signal on its lines throughout the state of

Indiana Indiana () is a U.S. state in the Midwestern United States. It is the 38th-largest by area and the 17th-most populous of the 50 States. Its capital and largest city is Indianapolis. Indiana was admitted to the United States as the 19th s ...

. The device used a green light, usually made from a standard

traffic signal Traffic lights, traffic signals, or stoplights – known also as robots in South Africa are signalling devices positioned at road intersections, pedestrian crossings, and other locations in order to control flows of traffic. Traffic light ...

, which always remained lit except when a train was present. The green light would then go dark, telling motorists to stop. A sign below or to the side of the signal read, "STOP When Signal Is Out" or "DANGER when light is out cross at your own risk".http://www.ikemeyer.com/phmtc/monon "Monon Grade Crossing Signal" This design was

fail-safe In engineering, a fail-safe is a design feature or practice that in the event of a specific type of failure, inherently responds in a way that will cause minimal or no harm to other equipment, to the environment or to people. Unlike inherent safe ...

, in that when the signal bulb was burned out, an approaching vehicle driver would assume a train was coming — until they eventually realized there was no train and just a burned-out signal.

References

{{Railway signalling Railway safety Railway signalling in Sweden Level crossings