The new LED signals, telling 2 & 3 aspects apart

[455driver]

Clueless. You need to go and sit down in a quiet room.

So can you explain to me why a 5 coach train sat at a red signal is in the overlap of the signal in rear meaning it is effectively double blocked?

Can you explain why there is a need for signals at the inbound end of the platform meaning you either get the double yellow with a platform number, then a single yellow at the platform end, or worse a single yellow with platform number followed by a red which may or may not clear on approach to a main aspect or calling on signal. If the train stops at this signal (if routed to platform 1) it will be across the junction blocking all other platforms?

Oh the linespeed is 15mph from the double yellow in, so not increasing the approach speed as alluded to earlier!

The signalling from Portsmouth Harbour to Fratton is a joke, ask anyone that has to drive over the bloody route!
I am glad I dont have to anymore.

 

[MarkyT]

Oh the linespeed is 15mph from the double yellow in, so not increasing the approach speed as alluded to earlier!

I suspected as much and I've just confirmed the same from the sectional appendix so you're right in this case the arrangement gives no advantage at all in this respect.

The problem is clause 3.1.3 in this document:

http://www.rgsonline.co.uk/Railway_...ng/Railway Group Standards/GKRT0044 Iss 2.pdf

which states:
"The distance between the protecting signal and the rear of the first train shall be minimised, as far as reasonably practicable, without compromising other requirements for signal positioning."

Now I would argue that providing an extra signal in this case is not a "reasonably practicable" way of ensuring the distance is minimised, taking all things into account, including the cost and subsequent maintenance of all that extra equipment. However as I explained before when the layout was designed all these requirements were being rushed in as a response to a string of permissive incidents in platforms so it's possible the designers went over the top, probably in an attempt to protect their individual and corporate butts. More recent designs probably wouldn't have those extra signals, at least approaching a terminal where they can provide no additional benefits.

PARS was not in my view amongst the most successful of signalling projects accomplished during that late Railtrack - early NR period for a number of reasons, although it did have some good modern features such as axle counters fitted throughout. Not long after, Siemens were removed from the contractors list for such major schemes, although they've since re-entered the UK market in a serious way by acquiring the rail signalling assets of Invensys, including the long established respected expertise and products of Westinghouse.

 

[455driver]

PARS was not in my view amongst the most successful of signalling projects accomplished during that late Railtrack - early NR period for a number of reasons,

Understatement of the year!

although it did have some good modern features such as axle counters fitted throughout.

I am no fan of axle counters due to them rendering TCOCs useless, but at least they seem to be working okay now instead of throwing a wobbly every 5 minutes.


Isnt it strange how, when they did Portsmouth, the 'standards' called for axle counters and conventional signal heads, but when they did Basingstoke (around the same time) the 'standards' called for track circuits and LED signal heads, 'standards' dont you just luv em!

 

[MarkyT]

Isnt it strange how, when they did Portsmouth, the 'standards' called for axle counters and conventional signal heads, but when they did Basingstoke (around the same time) the 'standards' called for track circuits and LED signal heads, 'standards' dont you just luv em!

I think it was as much about what the specific manufacturers could supply from their own product ranges. Axle Counters were an intrinsic part of the German style package Siemens proposed, whereas at Basingstoke the suppliers couldn't provide something similar with current approval status without buying it in from a third party and taking the resultant integration risk, even though axle counters would have been particularly suitable for the long 2 aspect sections on the Andover line, where very many short track circuit sections were provided instead, with power supplies and SSI cabinets every half mile or so which all have to be regularly tested and maintained. By contrast with axle counters there would have been almost no intermediate equipment between signals, as is the case with the long sections resignalled recently west of Salisbury using axle counters. Contracts are no longer managed the way Railtrack formulated for the BARS and PARS schemes with a lead supplier. The best mix of components are integrated today right from the initial design stage, from different manufacturers as neccessary.

 

[HarleyDavidson]

Clueless. You need to go and sit down in a quiet room.

Really? Perhaps if anyone consulted those of us who operate services and operate the signalling, they'd have a decent system. Even signalling staff think it's rubbish.

So now you have 4 signals between Southsea & Harbour, on the down at least two are superfluous and 1 in the wrong place and provide no benefits whatsoever. If they'd been installed on the up so that you had reversible working on that line it would be a different matter. But no.

Even Woking signalling doesn't work correctly either. Call yourselves engineers? I'd call you a bunch of amateurs compared to what BR engineers were.

 

[LowLevel]

To be fair the designers produce a scheme to Network Rail's spec.

Actual components and implementation seem to be rubbish. Recently resignalled areas of our routes are loathed by every level of the TOCs for unreliable equipment. Level crossings (especially the rubbish newly automated ones) and axle counters in particular, though points aren't far behind.

In the SWT lot's defence PARS broke ground for installation incompetence with huge delays and things like signals installed in (wrong) ridiculous locations. I remember it being a total humiliation for the infrastructure owner at the time.

 

[HSTEd]

The rot probably set in when signalling design and integration was outsourced.

In the old days it seems BR (and its predecessors) used to do far more in house - with resulting integration benefits.

But vertical integration is so old hat and socialist.

 

[The Planner]

But when things were outsourced, did experienced and competent staff not leave BR, and they still do from NR, to join the likes of Siemens etc.... with the lure of £££? It is much the same as people expecting a new franchise to be radically different, the staff are the same.

 

[edwin_m]

The rot probably set in when signalling design and integration was outsourced.

In the old days it seems BR (and its predecessors) used to do far more in house - with resulting integration benefits.

But vertical integration is so old hat and socialist.

Network Rail has brought most of this back in house.

 

[pompeyfan]

PARS was expected to take 2 months when it instead took 10 months? I still can't understand why fratton - PMH isn't fully reversible on all 3 lines and why there are feathers on the down in the up directions leaving fratton, surely the driver knows he's going to cross to the up eventually? And also why the down signal at St. Mary's protecting the diverging lines has feathers for both platforms in 2 and 3, or does that actually help the driver?

Is it me or does the PARS still seem incredibly unreliable, it seems like at least 3 times a week there will be an issue at some stage causing delays because of signalling. The only positive I've noticed is as a passenger when going Hilsea-cosham is not quite as much a crawl anymore!

 

[Jamesb1974]

Can't believe that no-one has commented on the ridiculous intensity levels of the LED signals.

It is all well and good to say that telling the difference between a single and double yellow is down to route knowledge, but when your following a shagged out Northern service that stops at every station, there is no guarantee that what 'should' be two yellows is two yellows. Obviously I drive according to the situation, but at a distance a LED two yellow aspect blends to one yellow extremely easily.

Or is it just me?

 

[CAF397]

I was at Leyland a few weeks back where signalling has been converted to LED. The signals on both up lines immediately to the south of the station have a flashing single yellow facility because the next set of up signals with feathers to the south control Euxton Junction where there is a 60mph turnout speed onto the Bolton line from the mainline where speed is 125mph.

Even from the platform end I was unable to tell if the flashing single yellow was from the lower red/yellow/green LED or from the higher single yellow spectacle. Assuming once again the previous up signal on the other side of Leyland station was displaying flashing double yellows.

The signals on the Euxton Jn end of Leyland station are still filament bulbs, not LEDs. Interestingly, on the Up Slow the speed is 30mph through the point work onto the Down Fast, then 50mph until onto the Up Bolton where it becomes 60 then 75.

 

[455driver]

Or is it just me?

No it isnt!

They are also stupidly bright as well!
--- old post above --- --- new post below ---

The signals on the Euxton Jn end of Leyland station are still filament bulbs, not LEDs. Interestingly, on the Up Slow the speed is 30mph through the point work onto the Down Fast, then 50mph until onto the Up Bolton where it becomes 60 then 75.

Are you sure?
A lot of normal heads are having the lamps replaced with LED packs!

 

[moggie]

Right, i've let some of you wibble on like spoilt kids throwing your teddies around so here's some facts.

Signalling schemes are specified by the infrastructure owner under their wonderful GRIP process. They will use either an in house of outsourced design group and yes the abilities vary but the whole point is that it meets a specification of requirements. These requirements are drawn up with the involvement of your TOC representatives.

They then get on with detailed design. The detailed design may or may not make use of new and novel equipment (i.e. LED signals etc). This will have been determined in the previous GRIP stage development process. The precise style / manufacturer of equipment may depend on the chosen supplier. These will all have been type approved for use by a formal testing and approval process. The signalling designer uses what is specified.

The position of signals will be proposed by a signalling scheme plan. This will have been through a detailed and protracted approval process by the infrastructure owner involving representatives of those companies which operate on the line, your TOC! There is ample opportunity for representation to me made for change. Anyone involved in signalling design will know how many times these plans are altered to accommodate these. All signalling layout plans (scheme Plans) design is scrutinised for compliance with standards, suitability for the purpose and justification of novel applications. I dare say the same people involved in this stage (G4) are the same involved with many of the southern based schemes.

The signals are then sighted / positioned for optimum performance. Guess who is represented on that exercise throughout the process? TOC's!

A final thought, when your spanking new and tired old rolling stock throws a wobbly is that the fault of the driver? Think about it?

One more thought, where did all those ex BR signal engineers go when BR was consigned to history? Well, those who had the sense and age took their retirement. The rest.........in those very companies now doing their level best to serve a backlog of demand and added design complexity (TPWS). Why the latter I ask?

One final thought. I've no practical knowledge of PARS other than I know it uses one of Railtrack's wished for systems that was to inject better competition into the UK signalling market! That ended up with the said company giving up on that in the UK and instead paying for Invensys RS.

 

[HSTEd]

Network Rail has brought most of this back in house.

I don't believe Network Rail is anywhere near as involved in the development of signalling equipment (such as SSI) as British Rail was.

 

[edwin_m]

I don't believe Network Rail is anywhere near as involved in the development of signalling equipment (such as SSI) as British Rail was.

Not in the development of the new equipment, but in scheme design.

 

[CAF397]

Are you sure?
A lot of normal heads are having the lamps replaced with LED packs!

yes, you can tell by the fading of the light when it extinguishes. It's not instantaneous like LED bulbs.

As for Leyland, the signal in rear of the station (the double yellow flasher) is a new LED Dorman signal head, but the ones at the station (the single yellow flasher) was definately the original signal head on Monday.

The mix between LED and traditional becomes apparent at night!

 

[MarkyT]

Not in the development of the new equipment, but in scheme design.

Network Rail is clearly heavily involved in the APPROVAL of new equipment however. Going back to HSTEd's SSI reference, that family of products and standards is still very much alive in the shape of 'forward compatible' offerings from the major manufacturers using more modern hardware. These modern processor-based interlockings can control much larger areas per system cubicle, yet accept bespoke geographical configuration data in the same format as developed for SSI, and they can interface with the same trackside data-link protocols for controlling points and signals in the field. In many cases they can, with a little work, be used as 'drop in replacements' for the original SSI signalbox equipment, with the entire trackside system of datalinks, power supplies and local TFMs (trackside function modules or 'object controllers') remaining entirely unchanged.

 

[brad465]

I would imagine if line speed is high enough there would still be repeater signals present in 2 aspect working, which can easily be made out by the distinct triangle above the signal number and control code

 

[carriageline]

I would imagine if line speed is high enough there would still be repeater signals present in 2 aspect working, which can easily be made out by the distinct triangle above the signal number and control code

2 aspect signalling required distants no matter what line speed. That's what I was taught anyway !


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[LowLevel]

I would imagine if line speed is high enough there would still be repeater signals present in 2 aspect working, which can easily be made out by the distinct triangle above the signal number and control code

All 2 aspect home signals have a distant signal related to them - one distant may relate to multiple signals (green distant in AB areas means all associated home signals are off) or be housed in a preceding 3 aspect signal, but you can't go from green to red without encountering a yellow (unless you're already running under a cautionary aspect in an AB area where say the semaphore outer home may be cleared on approach to drop you on to a red home/section signal).

 

[455driver]

yes, you can tell by the fading of the light when it extinguishes. It's not instantaneous like LED bulbs.

As for Leyland, the signal in rear of the station (the double yellow flasher) is a new LED Dorman signal head, but the ones at the station (the single yellow flasher) was definately the original signal head on Monday.

The mix between LED and traditional becomes apparent at night!

I wish they would change them all (for the LED packs) at the same time rather than piecemeal, but I much prefer the proper filament lamps as they are easier on the eye, especially at night.