Provision of SPAD Indicators

[St. Simon]

Hi,

 

I'm struggling to find any official material on the provision (and control) of SPAD Indicators. Obviously I'm not in the office today and with the fact that we don't install them any more means that all of the documents I can find just say "we don't install the anymore"

 

So, do any of you out there have information on any of the following:

 

1) How was the provision of a SPAD Indicator decided?

2) How was the position and direction of use decided (I assume it was always the same as the signal it applied to)?

3) How is a SPAD Indicator controlled? I know it's controlled by a train occupying the first track circuit in the route when the signal is at danger (I assume that it is the same for a delayed or last wheel replacement?), but how is it reset?

 

I'm thinking about putting one on the next layout, just for fun, but would like to do it in a prototypical fashion.

 

Simon

[big jim]

I think they were installed in either multi spad areas or areas with potential for conflict should a train have a spad, the only 2 I know of are hest bank on the wcml and grand jn in Birmingham

 

Regards the signal it applies to i think that’s irrelevant as there will be one on more than one line in a location if one is lit you have to stop immediately regardless of whether you have a spadded or not as if you don’t stop you may be heading towards a collision where someone else has spadded

 

I suppose it’s reset when various trains have had authority to continue and track circuits are clear?

[St. Simon]

I think they were installed in either multi spad areas or areas with potential for conflict should a train have a spad, the only 2 I know of are hest bank on the wcml and grand jn in Birmingham

 

Regards the signal it applies to i think that’s irrelevant as there will be one on more than one line in a location if one is lit you have to stop immediately regardless of whether you have a spadded or not as if you don’t stop you may be heading towards a collision where someone else has spadded

 

I suppose it’s reset when various trains have had authority to continue and track circuits are clear?

 

There's quite a few around Eastleigh which I have photographed, but I'm not sure where else they are. The ones at Eastleigh are suffixed by 'U' and 'D' which I assume for 'Up' and 'Down', but I don't know why that is.

 

Simon

[Dagworth]

There's quite a few around Eastleigh which I have photographed, but I'm not sure where else they are. The ones at Eastleigh are suffixed by 'U' and 'D' which I assume for 'Up' and 'Down', but I don't know why that is.

 

Simon

There was one at London Bridge at the up end of platform 6, probably all swept away now though

 

http://www.geograph.org.uk/photo/1019657

 

Andi

[russ p]

I think they are positioned where the consequences of a spad could lead to a serious accident.

All recently resignalled single lines have them , they are in other places but four pints and some wine stops me remembering at the moment!

Hopefully simon if your driving of model trains is good you can save making it operational

[Mark Saunders]

The first one was provided at Wincobank  junction at the end of the platform at Meadowhall Station coming from Barnsley as it was related to the number of SPAD at the protecting signal!

 

Platforms at the West end of Leeds were provided with these but were removed when resignalled and TPWS replaced these!

 

The provision was based on a risk of collision if there was a conflicting movement over a junction, an additional AWS magnet was provided at the signal and the SPAD indicator 200 yards in advance!

 

If a signal was passed at Danger on an adjacent line with the potential for conflicting movement it would be activated!

 

The SPAD indicator was activated as soon as the overlap was exceeded by the occupation of the track circuit.

 

All this was about 20 years ago!

 

Mark Saunders

[St. Simon]

Hopefully simon if your driving of model trains is good you can save making it operational

Hi Russ,

 

Whilst I’m fairly good at driving to signals (only fairly), some of my operating crew (Dad mainly!) aren’t that good!

 

So an operational SPAD Indicator enforces the ‘most SPADs buys the drinks’ rule

 

Simon

[St. Simon]

If a signal was passed at Danger on an adjacent line with the potential for conflicting movement it would be activated!

 

The SPAD indicator was activated as soon as the overlap was exceeded by the occupation of the track circuit.

 

All this was about 20 years ago!

 

Mark Saunders

Interesting, thanks Mark, would the activation be dependent on the position of points (I.e. Only if the points allowed a conflict to happen?)

 

Simon

[Mark Saunders]

An instructional video was produced by SPA films for safety briefs!

 

Copies must exist somewhere?

 

Mark Saunders

[beast66606]

Interesting, thanks Mark, would the activation be dependent on the position of points (I.e. Only if the points allowed a conflict to happen?)

 

Simon

 

I think one of the key risks is a head-on collision could occur if there was an over-run.

[Mark Saunders]

Interesting, thanks Mark, would the activation be dependent on the position of points (I.e. Only if the points allowed a conflict to happen?)

 

Simon

 

I do not recall if this was so but I seem to recall the instruction was even if the indicator on a adjacent line was activated you must stop!

 

Mark Saunders

[Mark Saunders]

I think one of the key risks is a head-on collision could occur if there was an over-run.

 

It seemed to me more aimed at converging/side swipes rather than head on!

 

Mark Saunders

[big jim]

I think one of the key risks is a head-on collision could occur if there was an over-run.

Don’t you have a working one on your layout Dave?

[PM47079]

There is one at Derby road at the start of the single line to trimley and one at trimley at the start of the single line to derby road. If one gets triggered they all start flashing. The first spad indicator I came across was in 1996 at Maryland when the great eastern mainline was resignalled

[beast66606]

Don’t you have a working one on your layout Dave?

 

On the now defunct Widnes, yes we had a working one, operated by the TC being occupied when the signal was at danger, it was provided because a SPAD could cause a head on collision and was positioned by a senior member of NR signal design hence my comment above ^ ^

[St. Simon]

On the now defunct Widnes, yes we had a working one, operated by the TC being occupied when the signal was at danger, it was provided because a SPAD could cause a head on collision and was positioned by a senior member of NR signal design hence my comment above ^ ^

Yes, I’ll have a chat with Mr Turner on Tuesday!

 

Simon

[PaulRhB]

Yes I was told it was by individual sites risk assessment. Tisbury had one at the station for the Tisbury to Wilton single line tokenless block but there wasn't one in the down direction into the loop. I was told it was because of the risk of start away SPADs when the guard gave the tip on Red, i.e. Where an outside influence might distract the driver. I assume the same might be true for the station starters at Eastleigh that had them as they were protecting junctions.

[Dagworth]

Yes I was told it was by individual sites risk assessment. Tisbury had one at the station for the Tisbury to Wilton single line tokenless block but there wasn't one in the down direction into the loop. I was told it was because of the risk of start away SPADs when the guard gave the tip on Red, i.e. Where an outside influence might distract the driver. I assume the same might be true for the station starters at Eastleigh that had them as they were protecting junctions.

Exactly the same as the one I posted at London Bridge, the risk of starting away against the red and coming together with something coming up the loop alongside.

 

Andi

[Supaned]

There's still one at Cheadle Hulme in the down direction where the Stoke line joins the Crewe line as there is potential for a head-on collision .

 

The indicator on the Aston line protecting Proof House Junction is due to be removed during Phase 6 of Birmingham Resignalling this coming May (which effectively reduces New St panel's area of control to the station itself). I was told that the indicator was being removed as TPWS means it is no longer necessary.

[beast66606]

Here's one I took last Friday (30 March 2018) at Magdalen Road (Watlington) - an SI for MR3, protecting the single line to Kings Lynn.

 

[Dye]

Interesting video called 'SPAD Indicators' on YouTube  https://www.youtube.com/watch?v=xje3coP9-IM

[RailWest]

Yes I was told it was by individual sites risk assessment. Tisbury had one at the station for the Tisbury to Wilton single line tokenless block but there wasn't one in the down direction into the loop. I was told it was because of the risk of start away SPADs when the guard gave the tip on Red, i.e. Where an outside influence might distract the driver. I assume the same might be true for the station starters at Eastleigh that had them as they were protecting junctions.

IIRC there also used to be one (not sure if still here) at the Salisbury end of the Up Main at Gillingham, but not any equivalent at the Yeovil end as far as I could see. Possibly provided because of the proximity to the platform and potential for distraction as suggested for Tisbury?

[timbowilts]

There are some still at Dartford Junction where there is a very messy layout of three reversible lines becoming two double track routes, all on a curved formation with a multi-arched over-bridge over the top of it! All the SPAD indicators are double suded so any train in either direction can see that someone has missed the peg.

 

Tim T

[PaulRhB]

IIRC there also used to be one (not sure if still here) at the Salisbury end of the Up Main at Gillingham, but not any equivalent at the Yeovil end as far as I could see. Possibly provided because of the proximity to the platform and potential for distraction as suggested for Tisbury?

The loop also extends way beyond the platform at the country end so the chance for the driver to realise and stop before the signal is longer. At the Tisbury end the platforms are right by points.

They are all out of use now on the WoE.

Edited April 2, 2018 by PaulRhB

[The Stationmaster]

Simon it might be worth asking in the office if there are still any copies of past issues of the Signalling Principles about although I suspect that those past 'residents' who had made personal copies took them with them when they left.