How many?

Cor blimey Chris you don't half pose 'em don't yer?

That is a question that will take time to answer as the guys will have to look at the operations books to tally them up. Maybe Mr Harsig or Citysig can answer a bit quicker but I doubt it.

But to give you an idea. Take as an average (average mind) 3 home signal, one starter and one advance starter for each station and you'll have a very rough estimate. Then double it.

Lightbulbs can be estimated by saying three for each signal and each bulb is double filamented. (not counting pigs ears)

That is only colour light signals. Disk signals NOT included. At a very rough geuss I would say over 5000

some have one per aspect but the tunnel signals two per aspect not all signal bulbs have 2 filaments , theres only 1 bulb which has 2 filaments and that is a 100v 33 1/2 W .

they may get round and put LED type lenses in

Parts of the Jubilee line extension have had LED signals for some time now, as are most train tail lights.

IN my area of California all the trafic signals are led now. They changed over Red first and the did the green and yellow. They have a very long life and many of the leds can go out before the signal fails

If you count the *Block Section Markers (part of the Central Line signalling, see www.davros.org/rail/signalling/articles/central.html for more info) as Signals, there's more.


* = AFAIK Block Section Markers are really called Block Marker Boards...? But the Central Line Signalling page suggests different...

They seem to be all the rage in Devon. Saw lots of sets of them when I was down there (lots of blooming roadworks as well!)

There's a new crossing they are putting in round my way and that appears to be LEDs. The lens looks flatter and more streamlined than "older" lights.

You are correct, they are block marker boards. While Clive Feather may know a fair bit, it isn't the first time he's made (large) innacuracies with centrall line signalling matters.

I don't want to be over-scaremongering, but there is a health and safety issue here. All LEDs are lasers, i.e. they emit narrow-band ('coherent') light. Whilst most common visible LEDs are classed as 'class 0' lasers, I'm not sure I'd be too chuffed if I was a driver at the prospect of having laser beams pointing directly at me all day long, particularly in tunnel environments. The occasional LED ground disk is one thing, but a wholescale change for main beam signals is quite another.
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I should think the answer to that is to angle the lens slightly downward. O r am I being naive?

I should think many people, like me, are staring a few in the face as they post here. I have a couple on my monitor, a couple on my keyboard, one on the stereo next to me, one flashes each time I change the TV channel.

I am sure by now that those people more technical than me have worked out which lasers to stick where. Give the cutting-type lasers to people like James Bond, and give the little twinkly ones to people who make things that light up.

Used in the wrong way, everything is dangerous.

The Piccadilly Line has quite a lot of LED signals, that have been Incorporated into the existing Signal Heads, I must admit, the are much better, as they are brighter and much stronger.