RAIB: Overspeed at Queen's Park

[GB]

If you have a signal conveniently located near the ESR then why not use it?

Signals are not used to control a specific speed of a train. Passing a single yellow, depending on location a train could be doing 60mph+.

 

[SpacePhoenix]

Do TPWS overspeed grids ever get used in conjunction with TSRs and ESRs when there is a great difference between the normal line speed and the temporary line speed?

 

[najaB]

Do TPWS overspeed grids ever get used in conjunction with TSRs and ESRs when there is a great difference between the normal line speed and the temporary line speed?

I know AWS magnets are, but I don't think TPWS grids are.

 

[tsr]

Signals are not used to control a specific speed of a train. Passing a single yellow, depending on location a train could be doing 60mph+.

I have actually known it to happen, but never experienced it with double/single yellows, only reds. There was one very recent case when there was a concern that speed restriction boards may not have been properly visible from a reasonable distance, so all trains were checked down to red at a certain signal, then when the driver alerted the signaller on the GSM-R, the signal was cleared. The speed at which a train could reasonably travel whilst still accelerating would have been easily sufficient to see the subsequent boards in place. The boards were still there but if passed at the usual permissible speed, reaction time may have been hindered. After a while the signaller actually started to get drivers to contact them, which might have been helpful in the first place... oh well, down to workload or some other routine reason, probably.

 

[Sunset route]

If you have a signal conveniently located near the ESR then why not use it?

There must be a good dozen TSR and ESRs in the location where I work all listed in miles and chains as that's what the engineers use. I have signal numbers and point numbers on my diagram. The two are not compatible systems and I've got not idea as to what exact signal or signals immediately protect the emergency speed board indicators (if required), warning boards or the commencement boards.

Ever wondered why you seem to run at caution over a quite a large area say station to station or junction to junction or a combination of the two, that is because we have to broaden our caution to ensure we cover any ESR or TSR with missing missing boards or not boarded at that moment in time.

Technology is creeping into the railway world but in someways we are still in the 19c.

The reason why it's takes the best part of two years to recruit and train a train driver is that we the passengers rely on their precise knowledge of the route, traction and rules to keep us safe when they are up front in that cab.

Stopping and cautioning a train every 3 to 4 minutes because a speed is being imposed but not boaded but can't be boarded straight will significantly increase a signallers workload sometimes to dangerous levels, especially if your controlling a multi track railway with a major station and multiple junctions as well. That's when the call demand comes out for control to tell the TOC/s to thin th service out. As a signaller you only really earn your money when things go wrong. There is a fine line from having a failure that increases your workload to point of taxing your abilities to totally degraded working that's becoming dangerous.

The railway does things the way it does because it's learnt the hard way to what happens when things go wrong. That's not to say that the boffins should look at better way of doing things with the ne technology as it comes online.

For me it's a good day if I've got you to and from the big city safely even better if it's somewhere near to the published times.

 

[GB]

I have actually known it to happen, but never experienced it with double/single yellows, only reds. There was one very recent case when there was a concern that speed restriction boards may not have been properly visible from a reasonable distance, so all trains were checked down to red at a certain signal, then when the driver alerted the signaller on the GSM-R, the signal was cleared. The speed at which a train could reasonably travel whilst still accelerating would have been easily sufficient to see the subsequent boards in place. The boards were still there but if passed at the usual permissible speed, reaction time may have been hindered. After a while the signaller actually started to get drivers to contact them, which might have been helpful in the first place... oh well, down to workload or some other routine reason, probably.

Reds are fair enough and is the proper way to do it when either the boards are not yet out or as you say, a board is missing, can't be deployed or in some way obscured etc.

But as said above, cautioning each train significantly adds to the workload and increases delay.

 

[cossie4i]

Years ago you was stopped and advised of such a ESR, if I remember correctly it was for any speed under 20mph.

 

[carriageline]

If you have a signal conveniently located near the ESR then why not use it?

Because a yellow signal doesn't mean anything in relation to speed maybe? A driver can speed over the ESR still, albeit not as severely.

Plus it creates extra workload for signallers, and also creates a SPAD risk.


Sent from my iPhone using Tapatalk

 

[SpacePhoenix]

Would there be any risk if TPWS overspeed grids were to be used with TSRs (would the use of TPWS overspeed grids be viable for ESRs?)

 

[edwin_m]

Would there be any risk if TPWS overspeed grids were to be used with TSRs (would the use of TPWS overspeed grids be viable for ESRs?)

No risk but quite a lot of hassle. The calculations for TPWS are more tricky than those for positioning a TSR board, and the loops would need their own power supply.

 

[DY444]

If you have a signal conveniently located near the ESR then why not use it?

The simple answer is because you can't do it at every signal on the network.

Signallers in MAS areas do not set individual aspects on signal. They set routes and the interlocking sorts out what the aspects displayed are.

An automatic signal reading to a controlled signal at danger will show a yellow aspect. An automatic reading to another automatic will not. The signaller might have the ability to set a specific automatic signal to danger or he may not depending on the technology employed in the box. For instance the NX schemes of the 60s and 70s tended to give this capability on every fifth signal in a sequence of automatic signals.

Attempting to use the signalling system for something when you cannot consistently apply it is a recipe for trouble.

 

[Railsigns]

Do TPWS overspeed grids ever get used in conjunction with TSRs and ESRs when there is a great difference between the normal line speed and the temporary line speed?

TSRs are only considered for TPWS fitment if they're planned to be in place for more than six months.