Bi-directional running

[Pete the Elaner]

I am intending to use 3-aspect signalling for my new layout & would also like to provide the correct signalling for a trailing crossover. Maximum speeds when forward running will be no more than 40-50mph so I didn't think that would justify 4-aspect.

Would wrong-line running have to be 3-aspect too? It is only intended to allow access to a siding on one side of the layout & possibly also emergency single-line running so I could easily limit this to 25/30. I was thinking 2-aspect would be sufficient?

[Mark Saunders]

I am intending to use 3-aspect signalling for my new layout & would also like to provide the correct signalling for a trailing crossover. Maximum speeds when forward running will be no more than 40-50mph so I didn't think that would justify 4-aspect.

Would wrong-line running have to be 3-aspect too? It is only intended to allow access to a siding on one side of the layout & possibly also emergency single-line running so I could easily limit this to 25/30. I was thinking 2-aspect would be sufficient?

Depends if it is fully bi-di which is fully signalled as per normal running direction or simplified simbids which only has abot 1 in 5 signals which is a fixed distant to a two aspect R/G stop signal with rout indicator. AWS not provided but TPWS is for the juction signal.

 

Mark Saunders

[Pete the Elaner]

Thanks Mark. It's a double track line but West London so alternative routes are available, therefore fully bi would not be necessary.. at least that's my excuse!

 

Now to figure out how to automate them on the layout....

[The Stationmaster]

Thanks Mark. It's a double track line but West London so alternative routes are available, therefore fully bi would not be necessary.. at least that's my excuse!

 

Now to figure out how to automate them on the layout....

 

 

You will also need a junction indicator ('feathers') even tho' the signal reads through the one route onto the correct line.

[Pete the Elaner]

You will also need a junction indicator ('feathers') even tho' the signal reads through the one route onto the correct line.

 

I was already looking forward to modelling those.

[Glorious NSE]

Ref SIMBIDS, if it's a trailing crossover between running lines the signal on the right hand line would also have 3 aspects as the route over the crossover would feed to the same signal as the adjacent 3 aspect signal does.

[Pete the Elaner]

Ref SIMBIDS, if it's a trailing crossover between running lines the signal on the right hand line would also have 3 aspects as the route over the crossover would feed to the same signal as the adjacent 3 aspect signal does.

 

I had not considered that, but it does make sense.

 

Thanks.

[secretsquirrel]

What about the use of ground/shunting signals?

thinking that you would need a similar aspect signal to the starter on the line running 'right direction' as there is access to the main running line in the same direction, but with a ground position signal at your trailing crossover (between the running lines) and then at the access for your siding. Think your starting signal should show red but ground signal should show white (clear tho proceed- may need further clarification) Have seen this set up before without feathers for routing. If u have the space, add a shunt limit on the main lines

[Edwin_m]

If the wrong line running is truly for emergency use you might not have any main aspects at all for the crossover routes, just shunt signals or maybe nothing at all if it is on a ground frame. Pilotman working is used to ensure the security of the single line - the pilotman is effectively a human version of a single line staff.

 

SIMBIDS has been provided on certain double track routes re-signalled after about 1990, when there is no easy diversionary route available (eg ECML north of Northallerton). It allows single-line working at reduced frequency during engineering work. Full bi-directional signalling on double tracks is rarely provided and even more rarely used - in practice the difficulties of single line working reduce the service density so much there is usually no point in providing full signalling for the wrong direction.

[Pete the Elaner]

What about the use of ground/shunting signals?

thinking that you would need a similar aspect signal to the starter on the line running 'right direction' as there is access to the main running line in the same direction, but with a ground position signal at your trailing crossover (between the running lines) and then at the access for your siding. Think your starting signal should show red but ground signal should show white (clear tho proceed- may need further clarification) Have seen this set up before without feathers for routing. If u have the space, add a shunt limit on the main lines

 

Ground position signal?

Starting signal?

Shunt limit?

 

I have no idea what any of the above mean

 

Edit: If I knew what they meant, I would probably not need to ask how to signal my layout

[Pete the Elaner]

Just found out a little about shunt limits thanks to another thread...

 

I don't think I need any:

The only time trains will be running wrong-line is when they enter the siding or approach the crossover.

 

& I think I've just found ground position signal too.

Is starter signal just a technical term for standard 2/3/4 aspect signal?

[Grovenor]

The only time trains will be running wrong-line is when they enter the siding or approach the crossover.

What sort of distance is involved here? If this is all within the one small area then you would just use shunt signals for the reverse moves.

If you can provide a plan it will be a lot easier to explain.

And yes, a starter is just a normal signal and is a term only really applicable to block working between signal boxes, not to continuous colour light signalling.

Regards

[Pete the Elaner]

I suppose I should have attached this in the first place.

 

Ignore the red lines. This is a low level yard totally disconnected from the main running lines.

 

There is a scale 300'-400' between the siding & crossover.

[Edwin_m]

You need to tell us whether the siding is for freight, stabling multiple units, terminating trains in passenger service (bay platform) or some other purpose. This may lead to the crossover being replaced by a facing one or removed completely.

[The Stationmaster]

Just found out a little about shunt limits thanks to another thread...

 

 

Is starter signal just a technical term for standard 2/3/4 aspect signal?

 

 

'Starting Signal' is an old term which was used with semaphore signalling and block working and also used (and still used) in signal naming where there are a succession of signals applying to the same line controlled by the same signalbox where the older methods of block signalling are in use.

 

it is meaningless when used in relation to an area wholly controlled by colour light signalling working under Track Circuit Block Regulations (i.e what most people would refer to as 'colour light signalling' and what is relevant to your railway).

 

To get a greater understanding of what you're after could you amplify the reply to Edwin's question by explaining what moves would be made as well please?

[phil-b259]

 

SIMBIDS has been provided on certain double track routes re-signalled after about 1990, when there is no easy diversionary route available (eg ECML north of Northallerton).

 

It has been around for longer than that, both the two track bits of the Brighton main line and the South Western main line to Southamton were equiped when resignalled in the early 80s

[Pete the Elaner]

The track is laid, wired, running & tested. I've gone too far to lift it now.

The siding is not a bay platform. I was thinking of it just to dump the odd P-way wagon, snowplough etc so it would not see much traffic.

 

The station will be an AC/DC changeover with AC to the left, so un-shoed units could potentially reverse, although I have never seen this done at such a small station so do not think it would be realistic.

I was thinking of it more as an emergency changeover to allow wrong-line running in case of a problem & a way to get to the southbound line from the siding.

[Edwin_m]

OK.

 

Three-aspect colour lights for departures from the left hand end of both platforms. Thus a train can arrive from the left into the top platform and reverse out again via the crossover. It is a main signal so the train can make this move with passengers on board. This could be the AC-only unit or you could terminate some workings here to add operational interest.

 

Shunt signal on the bottom track near the point ends with routes left to right into both main lines and the siding (probably a stencil route indicator). If bi-directional working whether SIMBIDS or full signalling then instead of this there would be a three-aspect signal with a feather for the crossover and a sub aspect, possibly offset to the right, for the siding. This would be alongside the signal controlling approach from the left on the top track, so possibly off-scene on this layout. I think the West London Line itself is bi-di signalled but not sure whether your route would be.

 

For exit from the siding there would be either a main signal or a shunt signal, depending on detail of when the re-signalling was done and how important the siding was at the time. I'm not sure whether a ground frame is possible here as it is close to the crossover.

 

Sorry to say you need a trap point on the siding.

[Pete the Elaner]

Fantastic. That sounds quite comprehensive.

 

Catch point. Good call, I had not even considered this. I've not gone too far to slip one of these in, but would have done so very soon so that suggestion could not have been more timely.

 

Thank you.

[Edwin_m]

Woke up in a cold sweat last night (well not quite) having realised that the platform end signal for the upper platform needs a left hand feather, illuminated whenever the signal is showing a proceed aspect for the crossover route. This is needed whether there is also a wrong-direction straight route or not, because the principle is that a feather is provided if there is a track leading straight ahead, even if trains do not normally use it in that direction.

[The Stationmaster]

Woke up in a cold sweat last night (well not quite) having realised that the platform end signal for the upper platform needs a left hand feather, illuminated whenever the signal is showing a proceed aspect for the crossover route. This is needed whether there is also a wrong-direction straight route or not, because the principle is that a feather is provided if there is a track leading straight ahead, even if trains do not normally use it in that direction.

 

Looks like I've been using Beast's invisible ink again (sorry Edwin, perhaps I didn't make it clear enough above?)

[beast66606]

Looks like I've been using Beast's invisible ink again (sorry Edwin, perhaps I didn't make it clear enough above?)

 

W lc me to t e c b

 

Woke up in a cold sweat last night (well not quite) having realised that the platform end signal for the upper platform needs a left hand feather, illuminated whenever the signal is showing a proceed aspect for the crossover route. This is needed whether there is also a wrong-direction straight route or not, because the principle is that a feather is provided if there is a track leading straight ahead, even if trains do not normally use it in that direction.

 

It wasn't always a principle for all circumstances though - sleep easy tonight Edwin.

[Edwin_m]

Looks like I've been using Beast's invisible ink again (sorry Edwin, perhaps I didn't make it clear enough above?)

 

Indeed you did point this out back up the thread. However I felt it was worth adding to my own reply, which might have been interpreted as a fully comprehensive response to the track plan but without this correction was actually incomplete.

[Pete the Elaner]

No worries, I'm not rushing so I've not bought any signals yet.

 

Thanks to all for your help.