'Ran through points'

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wilric

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Does the expression 'ran through points' mean that the points were set wrong and a train has ran through them or is it a generally used expression to say that a train has passed over correctly set points?
 
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swt_passenger

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Does the expression 'ran through points' mean that the points were set wrong and a train has ran through them or is it a generally used expression to say that a train has passed over correctly set points?

The former, I'd say.

Because points on passenger routes are generally locked in either the normal or reverse position, 'running through' them usually implies damage to the equipment. There are some exceptions to locking points in position, eg on certain passing loops, I believe.
 

wilric

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Also...when the points are locked and not set in favour of the train, I then assume that the trains weight and momentum will break the lock and force the points into position in favour of the train...is that correct?
 

driver9000

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A run through is when a train passes through trailing points that are set against it. This can cause considerable damage to the motors/point locks.
 

Sir_Clagalot

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Unless they are 'Run through points' as found in many sidings, whereby the force of the train moves them across if set in the other direction when coming from a set of sidings.
As a footnote, the points round TATA Scunthorpe are powered and they are changed using a plunger when heading towards the toe end and they motor across when detecting a train coming the other way if set for the other road.
 

KA4C

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Does the expression 'ran through points' mean that the points were set wrong and a train has ran through them

Yes, trailing points set against the movement being made and run through, causing damage
 

Railsigns

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Also...when the points are locked and not set in favour of the train, I then assume that the trains weight and momentum will break the lock and force the points into position in favour of the train...is that correct?

Usually, although running through HPSS type points can present a derailment risk to some trains.
 

wilric

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Will a computerised Automatic Routing System [ARS], that controls motorised points, detect that a train is about to enter wrongly set points [due to driver error] and so then change the points?
 

Railsigns

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Will a computerised Automatic Routing System [ARS], that controls motorised points, detect that a train is about to enter wrongly set points [due to driver error] and so then change the points?

No, never.
 

driver9000

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No, because a route needs to be locked and proved before a route can be cleared. Once the route is set points can't be moved unless the route is cancelled. An indication that points may have been run through would be the points indication in the signal box "flashing out of correspondence".

Edit - Railsigns has a faster web connection than I :D
 

jopsuk

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Some single-track lines (such as the West Highland, Kyle and Far North lines) use spring loaded points on the passing loops- so that trains can only ever enter the "correct" side of the loop.
 

wilric

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So it is not necessary for the computer to change the points because a run through will change them in favour of the train...which then leaves the problem that the driver is unable to telephone in the SPAD if he unaware of the SPAD
 

ralphchadkirk

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So it is not necessary for the computer to change the points because a run through will change them in favour of the train...which then leaves the problem that the driver is unable to telephone in the SPAD if he unaware of the SPAD

No, a run through will only change the direction of the points in the favour of the train if those points have been specifically designed to do so. They are quite rare. If a train runs through the commonest electrically driven motor points then it will break them, the motor, and quite a lot of ancillary equipment as well as a possible derailment.

ARS will not change the position of any points once the route has been selected and proved.
 

wilric

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So the weight and momentum of a train will force a run through upon motorised points that are not designed for a run through. The ARS will also not prevent such an occurrence.
 

Railsigns

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ARS means "Automatic Route Setting" and it has absolutely nothing to do with SPAD detection or mitigation. The presence or absence of ARS is completely irrelevant to this discussion.
 

wilric

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Yes ARS is irrelevant to this discussion other than to have established that it cannot prevent a run through.
 

O L Leigh

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Points run throughs do not tend to happen out on the mainline for the reasons stated, so forget about ARS and interlocking. On the mainline a route has to be set and proved before the protecting signals can be cleared, and once that happens that route is locked-in and cannot be altered except by cancelling the route, waiting for the system to time-out and resetting it.

Where points get run through is where they are not interlocked with the signalling, such as in yards, depots and sidings or where worked locally from a ground frame. These events are often caused by either poor communication between the shunter and driver or insufficient vigilance when setting the route or when taking it.

We've had one or two at Orient Way where either the shunter has set the road incorrectly or the driver has made a mistake and taken a train off the wrong road. Even though the points are power operated they are set locally by the shunter. It is the responsibility of both the shunter and the driver to ensure that the route is set correctly for the movement in order to prevent any incidents.

O L Leigh
 

KA4C

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NO doubt closely followed by the driver calling in to report a SPAD!

No. most point run through incidents occur either due to an error before authorising a driver to make a move within a T3 or a failure to check point settings prior to a driver being authorised to pass a signal at danger

Run through incidents following a SPAD are quite rare
 
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