A new signal to me.

[big jim]

oh yeah, while im still ranting, another concern with the type of signal in the o/p (which is actually a crop of one of my pics at warrington) is the lack of visor on it, my concern is should there be driving snow the piddly little holes the LEDs shine out of have the possibility of filling up with snow, an of course with them being led's there is no heat to melt the snow!

[russ p]

We call the crossing radars tic tacs or paracetamol's

[pitbull1845]

They may be too bright for the train drivers but are really useful at night as a navigation aid in a helicopter!  #JustSaying

[russ p]

They may be too bright for the train drivers but are really useful at night as a navigation aid in a helicopter! #JustSaying

So are laser pens :-)

[Horsetan]

An accident waiting to happen?

Is it that some Accountant has sat with his calculator and found that by installing these types of signals it could save Network Rail (ie Government Transport Dept) so many pounds a year? I`m sorry to say in many cases money savings outweigh any practical problems that are highlighted and these just fall on deaf ears, that is, until things go horribly wrong. Then guess where the blame ends up - on the poor driver who misread the signal.     

Who manufactures them? Is a British or EU Company?

Are they being installed on any of the EU railways?

I think the French, Germans and Dutch have LED signal heads, as well as the Austrians. The Swiss, I'm not sure - difficult to tell because of the lenses they use.

[russ p]

If they have lenses they aren't quite as bad, indeed there are conventional colour lights fitted with LED 'bulb' clusters that are much better but not as good as filament bulbs

[big jim]

on the plus side the best LED signals ive seen recently are the new ones they have replaced the oil lamps with in the shrewsbury semaphore signals, they are fantastic, you used to have to crawl down from coton hill to crewe jn's home signal and you couldnt see it until about 300m away, the new lamps mean you can see them as you first round the curve at the top of the bank, a good mile and a half away, makes the approach to shrewsbury so much better and quicker, especially as they are upping the linespeed down there, which is why they have probably had to change them

[russ p]

I much preferred Norwich to Ely with semaphores and the odd colour lights to the horrible LED tic-tac crossing line it is now

[Mark Saunders]

If you aren't impressed with these just wait till you see the new "Playcraft" style ones!

 

Mark Saunders

[Horsetan]

If they have lenses they aren't quite as bad, indeed there are conventional colour lights fitted with LED 'bulb' clusters that are much better but not as good as filament bulbs

That sounds like a Westinghouse product.

 

If you aren't impressed with these just wait till you see the new "Playcraft" style ones!

Already installed in Reading area, and some at Ealing Broadway.

[stewartingram]

Speaking as one who works in electronics, and not a signal engineer or a driver, can I add a few points about LEDs?

 

Compared to a filament bulb, the LED has a narrow "beam" pattern. Just look at the rear lightrs of a modern car; basically you can only see them from more or less straight ahead. If the "beam" angle is increased, the power of the light emitted is dispersed over a greater angle, so it does not appear as bright. (There is no real beam as such but I am using the term to keep it simple). With a filament bulb, the light is emitted in all directions (except of course through the base and contacts), then is concentrated into a beam by the reflector, and can be further improved by the glass optics in front of the bulb. The LED is basically a flat piece of silicon which glows; with no reflector, and limited optics moulded on it to disperse the light within a specified angle.

A bulb emits light over a wide frequency spectrum, the LED emits light only over a very narrow frequency band. Hence the light from an LED appears very bright though it doesn't have the penetrating power over distance. Again compare with those awful DRLs on the front of modern cars. Absolutely blinding to look at but little real useful illumination power to see with.

The filament bulb is basically (impure) white, any colour has to be added through optics placed in front of it. The LED emits light at a defined frequency ( ie a specified colour). They can be constructed with more than one piece of silicon within the actual LED, each piece will emit a different colour. (ie dual red and green). Just think of them as multiple bulbs within the same housing, and separate wiring to each.

Advantages of the LED include much longer life; bulbs are prone to failure as they run very hot and are fragile. LEDs consume much less current, so the cables to an LED can be thinner and cheaper, and power supply needed will be much less. Therefore installation, running costs, and maintenance costrs are much reduced.

 

Having seen the introduction of LEDs into  electronics, I used to think they were a fantastic invention. I think I still do provided they are used in the right place! At one time I was in favour of using them on my car, but having seen the widespread use of them I am actually now firmly opposed to them. Most newish cars have bright LEDs, but visible only within a narrow field of view, making them less visible. (Car styling also adds to the problem). The use of bright DRLs on the front is a particular contention for me; my left eye is defective, not closing down in bright light. Hence these DRLs are very painful, indeed dangerous to me.

 

Stewart

 

Just to add a story that is true. Near home their is a typical fen road running alongside a straight man-made river. A frequent occurrence of motorists falling into the river has led to the installation of average speed cameras with a speed limit of 50mph to enforce, where it used to be 60mph. Shortly after an accident there, which caused the cameras to be installed, I came home fron Doncaster in the dark, and entered this stretch of road. Distracted when joining the road, I forgot to set my cruise control and was driving along without it, but genuinely no more than 55mph. About 1/2 way along, there is a left turn, and at this junction my headlights picked up the Battenburg markings of a Police car . I slowed, then when just about upon the vehicle, saw a PC waving a torch which I took as an indication to turn left (thinking the road was blocked by another accident). It was at this point I saw the 2 flashing leds on his jacket (1 red, 1 blue). I drove off quite sedately, to be followed by the Police car with his Blues on! He was actually pulling me over. Turns out that he accused me of excessive speed (but wouldn't disclose the figure, which makes me think it wasn't too much, and I know I read my speedo at about 55mph). He then proceeded to read the riot act about his flashing leds being visible over 2 miles away! I calmly suggested that he made a formal safety complaint to his Sergeant, as they certainly were not visible.at more than 50 yards. He was quite shocked at that, but took heed, especially when I mentioned that until recently I worked at their HQ as a radio tech!

 

Stewart

[Suzie]

Traditional filament lamp signals (especially searchlights which have reflectors as well as lenses for focusing) have a very narrow beam, which is so narrow that as you approach the signal you get further out of the beam, and the apparent brightness goes down.

 

LED signals on the other hand (as shown in the original post) are built to a price rather than a spec, and they have completely omitted the beam forming optics, instead relying on the cheap plastic lenses on the individual LEDs. I don't know what the beam angle is on these LEDs, but it will be a lot wider than a Searchlight, and not have anything like the same sharpness of cuttoff such that you are likely to see the full brightness of the signal at a few tens of feet rather than two miles away. Because of this the brightness will have to be a compromise between being seen at distance (and be bright enough to penetrate fog) and blinding the driver at close range resulting in not meeting either requirement effectively.

 

The beam on a searchlight is so tight that tiny adjustments in its position will make a lot of difference to how it is seen, but turning an LED signal will not make any significant difference at all.

 

I can understand replacing filament lamps with LEDs, but not replacing the optics. Most of the reasoning behind the original 100 year old searchlight design still applies.

[jim.snowdon]

LED signals for use on Network Rail are most definitely built to a specification and although I can't speak from personal experience on every type, incorporate optical lenses so as to control the beam angle. The great benefit over traditional signals, and particularly the old-fashioned searchlight types, is that they require far less maintenance, as well as putting out significantly more light. The latter is why, at least in theory, the standards require that if there are several signal heads side by side, when one is replaced by an LED the others must also be replaced so that the relative brightness of the LED head does not swamp the other aspects.

 

Jim

[St. Simon]

If, as rumoured, the Cornwall job is being pushed back to the late twenties, it might go straight from lower quadrant semaphores to in-cab signalling.

When Cornwall is resignalled (temporarily) soon, it will retain semaphores with some new colour lights.

 

Simon

[BoD]

i may get passed out on the ertms next week, the crazy thing about that is you can pretty much drive a route without looking out of the window

How long before Google and others with their intelligent driverless car technologies become involved across the rail network? I'm guessing the algorithms involved would be much simpler and the technology is already capable of doing it.

[royaloak]

They said they would look into it....

Apparently it is a known problem but network rail probably have a lower electric bill so will be happy with them

No cheaper because they have to have a resistor in circuit so the LED draws the same current as the filament lamp so the lamp proving circuit still operates correctly.

 

The LED heads should be more reliable though!

[uax6]

If the accountants would actually realise that the railway need s&t teams to go round and do maintanance, and not just run around fixing faults, we would have two things:

More s&t staff, instead of lots of middle managers. After all it's the men on the ballast that keep the railway running.

Less failures, which would mean less money handed out to tocs. In the last eight years the it has become noticeable that the only maintanance that gets done is on AHBCs...

 

Andy g

['CHARD]

This signal is new to me, while I understand the meaning of the two bottom signs the "Dahlia" flower has no meaning. Perhaps someone could enlighten me please. Thanks

 

I hate this piece of crap.  From a purely 'railway landscape through which trains run' perspective, this is post-modern charmless dross.  

 

Which is why my perception of the railway for which I work is basically of an accountunt-led meal-ticket.  It has no bearing on my railway modelling hobby other than to consolidate me ever more firmly in 'the good old days.,'  An era that I never knew personally (other than toddling about on reins), but that was full of well-crafted artisan stage props, like semaphores and box-attended gated crossings.

[28XX]

What does the IRSE say about the new signal designs? They were once an independent body who rigorously tested any new developments, for just the sort of drawbacks mentioned above.

[FelixM]

I think the French, Germans and Dutch have LED signal heads, as well as the Austrians.

There are certainly no LED colour light signals in operation in Germany.

[phil-b259]

It appears that there is a purge on Semaphores, as the resignallings that seem to be pressing ahead appear to be aimed at semaphore areas. Which probably means that yet more of these 'things' will be installed.

 

Andy G

With resignallings, it's a simple fact that you make grater wage savings by closing mechanical boxes than existing power signalling installations. For example when NR resignalled the Coastway East lines in Sussex they closed 5 signal boxes 4 of which were open 24/7 with a single ROC workstation.

 

Thus resignalling Cornwall makes financial sense given the amount of boxes (and signalmen) you could get rid of - the same was true of the ex LSWR route via Yeovil.

 

By contrast replacing a single NX Panel at somewhere like Three Bridges ASC actually requires more staff, not less as the H&S rules around people who work with VDU based equipment mean they require more frequent breaks so as to prevent eye strain.

[Grovenor]

What does the IRSE say about the new signal designs? They were once an independent body who rigorously tested any new developments, for just the sort of drawbacks mentioned above.

I don't think the IRSE has ever been any sort of testing house.

Regards

[phil-b259]

We call the crossing radars tic tacs or paracetamol's

I have also heard them referred to as a lady's sanitary product or a Minion

[phil-b259]

No cheaper because they have to have a resistor in circuit so the LED draws the same current as the filament lamp so the lamp proving circuit still operates correctly.

 

The LED heads should be more reliable though!

Indeed - which means they require less frequent visits from the maintence gangs who can be reduced / redeployed on other things.

[phil-b259]

What does the IRSE say about the new signal designs? They were once an independent body who rigorously tested any new developments, for just the sort of drawbacks mentioned above.

The IRSE are not a regulatory body , nor do they do "Which" style testing on different manufacturers products.

 

The IRSE instead focus on supporting designers (as in designing a scheme, not individual components) and maintainers of signalling equipment to obtain professional accreditation for those roles, plus bringing the latest developments in signalling equipment / principles to their members. Thus when they do discuss new equipment it's very much in the vein of 'news' rather than 'review' plus they do regularly look at developments in overseas signalling.