Theatre Indicators, On all the time or just when Signal is Off

[Edwin_m]

Yes indeed - basically the same suggestion I offered somewhere back up the thread. Glad to see we are in violent agreement at last!

[beast66606]

Yes indeed - basically the same suggestion I offered somewhere back up the thread. Glad to see we are in violent agreement at last!

 

[Tigger]

Here is a quick video of my microprocessor controlled signal. Following all you advice I hope this is now prototypical

 

http://www.youtube.com/watch?v=ixQ6qN_QoRk

 

Plaese let me know if there are any other improvements needed

signal_0002.wmv

[beast66606]

Looks good to me

[Horsetan]

Here is a quick video of my microprocessor controlled signal. Following all you advice I hope this is now prototypical.....

 

Looks alright in terms of phasing.

 

Is that a distant signal? The bottom aspect looks yellow rather than red. If it is, I didn't know distant signals could come with theatre indicators.

[royaloak]

 

Looks alright in terms of phasing.

 

Is that a distant signal? The bottom aspect looks yellow rather than red. If it is, I didn't know distant signals could come with theatre indicators.

They cant, you can only get a route off a stop signal.

 

Timing looks (very) good.

[beast66606]

 

Looks alright in terms of phasing.

 

Is that a distant signal? The bottom aspect looks yellow rather than red. If it is, I didn't know distant signals could come with theatre indicators.

 

LED Red is often rendered as yellow(ish) by modern digital cameras, happens if you video the prototype too

[Tigger]

It is yellow I will change it to red. Thanks for that

[Edwin_m]

Both colours looked the same on my screen. If the signal reads into a terminus then the "proceed" aspect should be yellow not green (if it isn't already). The indicator looks good to me.

[Tigger]

There are some better pictures of the Signal with the Teatre Indicator here Tiggers SWAG Module

[Coach bogie]

I was at Northallerton, last night, seeing of my good lady on the London train. She travelled Grand Central which is always signalled to the relief line to York. As I have been following this thread, I watched the signal. The feather was illuminated with the signal on red for 4 seconds before the aspect changed to Green. The same count applied to the following trans Pennine service signalled to the same route so it was not a one off.

 

Thanks for the new game for my nine year old, now checking all junction signals he sees.

 

Regards

 

MIke Wiltshire

[Horsetan]

As an exception to the usual practice, I was observing the last approach signal to London Bridge station, yesterday evening on the north side (Tooley Street side). This is a standard 4-aspect head with a theatre indicator.

 

When the signal cleared, both the green aspect and the theatre indicator illuminated simultaneously, the latter displaying the number "1". I take it this is not a common occurrence? Or was it possibly because the route was already correctly set to no.1 line / platform?

[beast66606]

As an exception to the usual practice, I was observing the last approach signal to London Bridge station, yesterday evening on the north side (Tooley Street side). This is a standard 4-aspect head with a theatre indicator.

 

When the signal cleared, both the green aspect and the theatre indicator illuminated simultaneously, the latter displaying the number "1". I take it this is not a common occurrence? Or was it possibly because the route was already correctly set to no.1 line / platform?

 

Probably the interlocking used is different, I'm guessing relays in this instance, as mentioned by me (and possibly others) above (and it's not an exception)

[phil-b259]

As an exception to the usual practice, I was observing the last approach signal to London Bridge station, yesterday evening on the north side (Tooley Street side). This is a standard 4-aspect head with a theatre indicator.

 

When the signal cleared, both the green aspect and the theatre indicator illuminated simultaneously, the latter displaying the number "1". I take it this is not a common occurrence? Or was it possibly because the route was already correctly set to no.1 line / platform?

 

Two things spring to mind, firstly different types of interlockings have different response times. London Bridge is a mid 1970s installation and will therefore use indavidual relays in the interlocking, which will be faster than a computer based system (SSI) whose response times have been discussed on another thread. The second thing is that where line speeds are low route indicators, particularly theatre types will not be lamp proved. The reasoning being that should a driver be unable to determine what indication is being given, they will have time to stop before going past the signal and be able to query the route with the signaller. For example the theatre indicators on the Three Bridges scheme are all utalise a matrix of pigmy lamps to display a letter / number and these are not lamp proved in the sense that the driver will still get a proceed, even with all lamps in the theatre blank. Back at the box however the signal will show a blank aspect thus indicating there is a problem. Also the ammount of lamps that have to be out to trigger this will vary depending on what letter / number is being displayed and how 'readable' it is with various lamps out

[The Stationmaster]

As an exception to the usual practice, I was observing the last approach signal to London Bridge station, yesterday evening on the north side (Tooley Street side). This is a standard 4-aspect head with a theatre indicator.

 

When the signal cleared, both the green aspect and the theatre indicator illuminated simultaneously, the latter displaying the number "1". I take it this is not a common occurrence? Or was it possibly because the route was already correctly set to no.1 line / platform?

Relay interlocking so therefore quicker than SSI - in practice there would be a delay but so slight in some installations as to appear virtually instantaneous whilst others are a lot slower (e.g. R79 Up Main at Reading - used to be very slow for some reason).

[Grovenor]

There is not always lamp proving on theatres, especially if all routes are the same speed and length as into a terminus. See post 10.

Keith

[Coach bogie]

Was at Northallerton in daylight for the first time this year. The south bound signal is well known for the feather lighting before the clear aspect is shown. After seeing my wife off on the London train the points changed to the slow for the following Trans Pennine service. The feather lit and we counted 3 seconds before the green showed. I had the camera set to power wind and I now have 16 shots of illuminated feather with a red aspect showing. It has become a new hobby for my nine year old. The northbound feather for Tees from the ECML usually clears at the same time. Low Gates box is only a few hundred yards away so I assume this may contribute to the simultaneous illumination.

 

Mike Wiltshire

[beast66606]

The feather lit and we counted 3 seconds before the green showed. I had the camera set to power wind and I now have 16 shots of illuminated feather with a red aspect showing. It has become a new hobby for my nine year old.

 

Try catching the main aspect as it clears, so you have a red and a green lit (with no Photoshop trickery to assist)

[coachmann]

Oldham Clegg Street Station had indicators on the signal brackets that showed M or B. In our childs simplistic minds these letters stood for Manchester and Blackpool....! No doubt they indicated Main or Branch, but quite where the Main was puzzles me. I wonder if Main referred to the L&Y Oldham Loop line to Rochdale and Branch the line to Greenfield and Delph?

[Edwin_m]

The Thirsk-Northallerton area was re-signalled with a hybrid of SSI and relays, which could well mean that the delays between route indicator and aspect clearing are longer here than on a pure SSI scheme.

[Coach bogie]

Try catching the main aspect as it clears, so you have a red and a green lit (with no Photoshop trickery to assist)

 

You are spot on. I had a shot of this without realising it.

 

Mike Wiltshire

[ZippyHG]

As an exception to the usual practice, I was observing the last approach signal to London Bridge station, yesterday evening on the north side (Tooley Street side). This is a standard 4-aspect head with a theatre indicator.

 

When the signal cleared, both the green aspect and the theatre indicator illuminated simultaneously, the latter displaying the number "1". I take it this is not a common occurrence? Or was it possibly because the route was already correctly set to no.1 line / platform?

 

Hi, the cannon street station, P1,2 and 3 and the cannon street reversibles are SSI based interlocking. The reason the theater indicator comes off at the same time as the signal is because it is not proved alight.