Catch point
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A catch point is a device installed at a rail siding to prevent unattended wagons and engines running away uncontrolled onto the main line and causing trouble. It may also be used where a secondary track joins a main line.
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[edit] Function
Catch points may also be used in order to "catch" runaway wagons that may have decoupled in an uphill segment of line which may collide with following trains.
Runaways may go unnoticed, especially before the days of track circuits, leading to a severe crash involving at worst, a passenger train. It is also better to trap the runaways at low speed before they build up speed on a long falling grade, and, occasionally catchpoints are expanded into a safety siding.
The catchpoints may consist of a full turnout with two switchblades (rails), or as little as a single switchblade.
[edit] Fail safe
The catchpoints should preferably be far enough away from the mainline to ensure that any runaway wagon stops clear of the mainline. It is not always possible to guarantee this, particularly if space is limited. If the line is track circuited, then a track circuit interrupter will be fitted to one of the run-off rails in order to break the track circuit and put main line signals to stop.
[edit] Accident
- April 1, 1987 – Burnham, Illinois - wagon in siding passes derail/catchpoint and lies foul of mainline, but due rusty rails, does not shunt track circuit or put signals to stop.
[edit] See also
[edit] External links
