Route indicator or Theatre box

[pendlerail]

It was asked during construction of a layout at the club about the rules regarding the above,

but the question has come to my mind again because of developments at Salford Crescent.

What are the rules about the above, but as recently Salford Crescent was resignalled for Bi directional running towards Ordsall Lane Jn with Route indicators.

however over the last week the same signals have been replaced with Theatre Boxes?

So is it just a whim?

At the time I assumed line speed was a reason, Higher speed Route indicator, low speed Theatre box,

Thanks Phil

[St. Simon]

It was asked during construction of a layout at the club about the rules regarding the above,

but the question has come to my mind again because of developments at Salford Crescent.

What are the rules about the above, but as recently Salford Crescent was resignalled for Bi directional running towards Ordsall Lane Jn with Route indicators.

however over the last week the same signals have been replaced with Theatre Boxes?

So is it just a whim?

At the time I assumed line speed was a reason, Higher speed Route indicator, low speed Theatre box,

Thanks Phil

Hi,

 

Technically Route Indicators and Threatre Boxes are exactly the same thing, I presume you mean Junction Indicators (Feathers).

 

Its never just a whim, it's designed and assessed by a sighting committee, it's probably one or more of the following reasons:

 

1) The signalling has been changed so there are now more than 7 routes from the signal

2) A main route has been added or altered so that it is now a route into a terminal platform or sidings

3) The layout has been altered so that an SI is needed to provide a more descriptive route indication (letters instead of a general direction)

4) Alternative routes are being provided

 

A change from an JI to an SI might require line speed alterations (60mph max on an SI) or a derogation against the Junction Signalling Standard.

 

Simon

[pendlerail]

Thanks, yes I did mean Junction indicators, the choice of routes at Salford Crescent have not changed but the signals have where previously there were feathers for routes, now we have Theatre Boxes, still 3 possible routes. It is possible that a 4th route could be added at Crescent, to create Bi Directional running into Salford Central, but that would require new pointwork in an already cramped junction layout.

Unless the next signals are to receive boards with the Letters given at the previous signal as in the west end of Manchester Victoria.

ie, the lines are named Up Salford Fast, Down Salford Fast, Up Salford Slow and Down Salford Slow If approaching Victoria but leaving Victoria they are E, D, C and B.

[TheSignalEngineer]

I'm not familiar with what is going on there at the moment but it may be that the combination of indications required if feathers were to be used would be prohibited under the current signal sighting rules.