SPAD indicators

[swt_passenger]

Are these signals now becoming generally obsolescent?

I remember them being removed from the Southampton station area a couple of years back, now at least three of the SPADIs visible from the platform at Eastleigh have been bagged up during the course of this week.

Is there a systematic plan to take them out?

 

[455driver]

Yes they are obsolete, being replaced by TPWS loops which stop the train.

 

[swt_passenger]

Yes they are obsolete, being replaced by TPWS loops which stop the train.

I realised that the TPWS stops would probably make them almost redundant, but what I suppose I'm getting at is that the SPAD indicators have been present alongside TPWS for quite a few years now, has a recent decision been taken to finally and proactively remove them?

Last time this was discussed I think most people thought they'd probably be left until the next major work on the signalling in the relevant area; in the case of Southampton the interlockings were being replaced at the same time.

 

[Pacerpilot]

A brand spanking new LED one went in at Margam when Port Talbot East was resignalled. It protects the start of Bi-Di working over the Down line.

 

[455driver]

I realised that the TPWS stops would probably make them almost redundant, but what I suppose I'm getting at is that the SPAD indicators have been present alongside TPWS for quite a few years now, has a recent decision been taken to finally and proactively remove them?

Last time this was discussed I think most people thought they'd probably be left until the next major work on the signalling in the relevant area; in the case of Southampton the interlockings were being replaced at the same time.

Just because the SPAD indicator is there doesnt mean it is connected up!

 

[carriageline]

I would be surprised if it was there but not connected up. Surely that constitutes a 'bag over the head' (quit your sniggering) with a X over it jobby if it was OOU.

Never say never I suppose


Sent from my iPhone using Tapatalk

 

[Aictos]

I wouldn't know what one was in any case, no idea what they look like

 

[causton]

I wouldn't know what one was in any case, no idea what they look like

http://lmgtfy.com/?q=spad+indicator+images

 

[swt_passenger]

I would be surprised if it was there but not connected up. Surely that constitutes a 'bag over the head' (quit your sniggering) with a X over it jobby if it was OOU.

When I wrote 'bagged up' in the first post I did mean in the normal railway manner, with the big white cross. So the normal practice when something goes out of use, rather than 455driver's suggestion that they could be visible but disconnected...

 

[ComUtoR]

Yes they are obsolete, being replaced by TPWS loops which stop the train.

Do they pre-date TPWS ?

I know couple but they have been there for as long as I can remember but I have only known TPWS

 

[Railsigns]

Do they pre-date TPWS ?

Yes, by about five years.

 

[ComUtoR]

Cheers

I've only ever seen one flashing once and the one I pass on a regular basis is so covered with grime if it was activated you probably wouldn't see it.

 

[CockneySparrow]

Yes they are obsolete, being replaced by TPWS loops which stop the train.

Is every train "now" fitted with this gear, I think not!

 

[swt_passenger]

Is every train "now" fitted with this gear, I think not!

You think wrongly, I can only assume you must be thinking of some other technology.

NR announced that the "entire train fleet" was TPWS fitted way back in 2003:

http://www.networkrailmediacentre.c...newsareaid=2&releaseid=318&searchcategoryid=2

 

[ainsworth74]

And isn't it a requirement to run on the network these day as well? Even for steam locomotives I believe.

 

[455driver]

Is every train "now" fitted with this gear, I think not!

Okay you know better than me so you can answer all the questions now smart arse!

Oh and you are wrong as well! :roll:

 

[carriageline]

Okay you know better than me so you can answer all the questions now smart arse!



Oh and you are wrong as well! :roll:

I would surely bloody hope so!! I don't know how you kept your cool tbf


Sent from my iPhone using Tapatalk

 

[cjmillsnun]

And isn't it a requirement to run on the network these day as well? Even for steam locomotives I believe.

It is indeed.

 

[ComUtoR]

On a semi related subject. TPWS is not fitted to every signal. Is there any reason why not ? For clarity I'm talking about Stop signals. I think there is a few automatic signals (4-aspects) on SE that do not have a grid fitted. Pretty sure they are on straight line with no conflicts.

 

[Llama]

There will be more than a few, most automatic signals (unless required as mitigation for a restricted overlap or other risk at the signal in advance) are not fitted. Quite a few GPLs are not fitted too. Have a look at the group standards.

 

[Railsigns]

There will be more than a few, most automatic signals (unless required as mitigation for a restricted overlap or other risk at the signal in advance) are not fitted. Quite a few GPLs are not fitted too. Have a look at the group standards.

It's a Network Rail company standard (NR/SP/SIG/10137) that outlines the selection criteria for fitting TPWS. Generally speaking, shunting signals and signals that only protect a rear-end collision don't require TPWS.

 

[ComUtoR]

Cheers as always

 

[edwin_m]

Any signal that was high-risk enough to get a SPAD indicator would certainly have qualified to get TPWS grids.

 

[CAF397]

Some stop signals that have a 'flank protection' to avoid collisions, that being points set To avoid a potential head on collision don't have TPWS. The one I am thinking of here is PN56 on the Up Slow protecting Farington Curve Jn near Preston. If a train is to SPAD the signal, it will either go straight on (no danger of collision), or if the points are set for the diverging route, then the signal protecting the Down Slow will be maintained at danger and that has TPWS fitted, his rendering TPWS at PN56 redundant.

Of course here I am referring to TPWS Train Stop. The signal will still have TPWS Over Speed fitted to detect if the train is approaching the signal too fast.

 

[Railsigns]

Some stop signals that have a 'flank protection' to avoid collisions, that being points set To avoid a potential head on collision don't have TPWS. The one I am thinking of here is PN56 on the Up Slow protecting Farington Curve Jn near Preston. If a train is to SPAD the signal, it will either go straight on (no danger of collision), or if the points are set for the diverging route, then the signal protecting the Down Slow will be maintained at danger and that has TPWS fitted, his rendering TPWS at PN56 redundant.

Of course here I am referring to TPWS Train Stop. The signal will still have TPWS Over Speed fitted to detect if the train is approaching the signal too fast.

That can't be right. It never happens that a signal is fitted with an Overspeed System but has no Train Stop System. I did check the latest available signalling plan for the area, which shows PN56 having neither TSS nor OSS.

 

[142094]

Tyne and Wear Metro doesn't use TPWS, however that is the only example that I know of.

 

[CAF397]

Thanks for the clarification Railsigns. I was hesitant whether it would be fitted with a OSS, but figured it must have. I shall go with my gut instinct next time!

 

[MarkyT]

Tyne and Wear Metro doesn't use TPWS, however that is the only example that I know of.

T&W Metro does have its own train-stop system based on German PZB (Indusi) though. On the joint running section to Sunderland all the signals are fitted with both PZB and TPWS.

 

[edwin_m]

T&W Metro does have its own train-stop system based on German PZB (Indusi) though. On the joint running section to Sunderland all the signals are fitted with both PZB and TPWS.

And it is all signals on this case. With Metrocars having less structural strength than trains, even a tail-end collision is considered unacceptable. The signal spacing and overlap lengths on this route allow the TPWS to stop any SPAD train before it reaches a point where a collision might happen, assuming the TPWS functions correctly and the train is not exceeding line speed.

 

[142094]

T&W Metro does have its own train-stop system based on German PZB (Indusi) though. On the joint running section to Sunderland all the signals are fitted with both PZB and TPWS.

It certainly does, but just to clarify for others, Metro units do not use TPWS.

In fact, apart from the signals, Indusi magnets are also at other 'strategic' locations on the line where TPWS isn't for heavy rail trains.