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railway. Any unauthorised and out of control vehicle running down the steep gradient in the single line section could collide with a train or derail itself at high speed, possibly having fatal consequences. Therefore, a set of sprung catch points are placed in the uphill side of the passing loop to
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turnout is used to prevent any unauthorised movement that may otherwise obstruct the main line. The trap points also prevent any damage that may be done by a vehicle passing over points not set for traffic joining the main line. In the
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Trap points should preferably be positioned to ensure that any unauthorised vehicle is stopped a safe distance from the main line. However, due to space limitations, it is not always possible to guarantee this.
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are double trap points where the tongues of rail are longer, so that the trap point rail nearest the main line continues over the siding rail with a common crossing or frog.
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is used to make sure that the signal cannot be set to allow passage onto the main line until the trap points have been aligned to ensure this movement can take place.
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derail runaway vehicles, whilst trap points and a sand drag are used to stop any traffic passing the starting signal at danger from entering the single line section.
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point blades are held in a position to derail any vehicle travelling downhill. However, any traffic travelling in the correct (uphill) direction can pass over the
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or other granular material, or a siding where the rails are within sand-filled troughs. This method of stopping a vehicle travelling at speed is preferred over a
258:. In these cases, a lever may be provided to temporarily override the catch points and allow safe passage down the gradient in certain controlled circumstances.
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safely, pushing the switch blades into the appropriate position. Once the wheels have passed, the trap points are forced back into the derailing position by
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consists of only one switch rail, leading away from the main line to a short tongue of rail. This is usually placed in the rail furthest from the main line.
337:. The station lies towards the top of a long steep climb (which runs uphill from left to right in this diagram), where two parallel tracks form a
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to the vehicle involved. Sand drags were often placed at the bottom of steep hills to catch wagons which had broken away from their train.
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from its train. In either case, the runaway vehicle could collide with a train further down the slope, causing a serious accident.
281:, which automatically stop any vehicles separated from their train, were widely adopted, making catch points largely obsolete.
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controlling passage onto a main line is set to "stop", the trap points are set to derail any vehicle passing that signal.
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will be fitted to one of the run-off rails in order to break the track circuit and set main line signals to 'danger'.
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Both catch points and trap points are used to prevent runaways and unauthorised movements at the north end of
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are a full turnout, leading to two tongues. Usually the tongue nearer the main line is longer than the other.
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is a short dead-end siding leading to some method of stopping a vehicle, such as a sand drag or
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277:. Catch points continued to be used in the UK until the mid-20th Century. At this time,
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Diagram showing the use of trap points to protect the main line at the exit of a siding.
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444:(4th edition (1971) ed.). The Permanent Way Institution. pp. pp. 150-152.
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376:"Glossary of Signalling Terms, Railway Group Guidance Note GK/GN0802, Issue One"
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is another device used for the same purposes as catch and trap points.
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runaway vehicles on steep slopes, and trap points are used to protect
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In some cases, catch points and trap points direct vehicles into a
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The type of trap points to be used depends on factors such as the
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There are several different ways of constructing trap points:
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An insulated track circuit interrupter fitted to trap points.
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British
Railway Track: Design, Construction and Maintenance
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Track diagram of the north end of
Goathland station.
76:. Either of these track arrangements may lead to a
261:The use of catch points became widespread in the
134:An unauthorised movement may be due to a runaway
68:from unauthorised vehicles moving onto them from
122:or where a secondary track joins a main line. A
242:or a single switch blade. In some cases, on a
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34:at the exit of Stoke Gifford Rail Yard near
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227:are used where track follows a rising
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238:Catch points may consist of a full
269:, where runaway wagons containing
60:devices. Catch points are used to
30:Double trap points protecting the
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383:Rail Safety and Standards Board
36:Bristol Parkway railway station
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335:North Yorkshire Moors Railway
305:simply leading to a mound of
118:are found at the exit from a
273:(kerosene) collided with an
297:, also sometimes called an
279:continuous automatic brakes
212:of the siding, and whether
191:Trap points with a crossing
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333:station, on the preserved
140:passing a signal at danger
163:track circuit interrupter
267:Abergele train disaster
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32:South Wales Main Line
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440:D. H. Coombs (ed.).
198:trap road with stops
169:Types of trap points
138:, or may be a train
216:enter the siding.
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185:Double trap points
179:single tongue trap
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66:main railway lines
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406:External link in
317:as there is less
157:If the lines are
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49:are types of
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387:. Retrieved
343:single track
339:passing loop
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299:arrestor bed
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271:paraffin oil
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225:Catch points
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148:Interlocking
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74:branch lines
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43:Catch points
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389:18 February
315:buffer stop
214:locomotives
202:buffer stop
116:Trap points
95:Trap points
47:trap points
358:References
265:after the
18:User:Ollie
450:cite book
331:Goathland
291:sand drag
285:Sand drag
233:decoupled
161:, then a
142:. When a
78:sand drag
399:cite web
248:trailing
229:gradient
210:gradient
325:Example
256:springs
252:turnout
240:turnout
70:sidings
55:railway
51:turnout
311:gravel
303:siding
144:signal
124:facing
120:siding
89:derail
62:derail
58:safety
379:(PDF)
319:Shock
244:track
136:wagon
16:<
462:help
414:help
391:2007
307:sand
45:and
293:or
80:or
72:or
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448:{{
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