Question re: low-density lines, shunting limits and advanced starters

[signalmaintainer]

There is a question or two lurking in here. But please let me set the scenario:

 

1) On Ettinsmoor, the distance between the signal box at Ettinsmoor station and the junction with the West Coast Main Line is about six miles, give or take a chain.

 

2) A starter signal governs movement from the Ettinsmoor station platform, with adjacent ground signals governing movement from the passing loop and the goods siding. A stopping signal at the signal box governs movement into the station platform. A subsidiary signal on the stopping signal's mast governs movement into the goods siding.

 

3) At the junction a signal box (of course) controls movement onto and off of the Ettinsmoor branch.

 

4) The only other location requiring authority to enter or exit is the quarry spur. Its ground frame is electrically unlocked from the Ettinsmoor signal box when a train crew surrenders their token at the ground frame hut.

 

OK, enough of the long wind up. Here's the pitch: Is an advanced starter signal required at the Etttinsmoor signal box? Caveat: the local goods uses the main track as a head shunt when working the good siding. So will a Limit of Shunt sign do just as well? And is an advanced starter really necessary when the next signal is nearly 6 miles away at teh WCML junction?

 

The JPEG below is actually a photo of the signal diagram. I apologize for the blotchiness. Oh, and the term "catch points" should be "trap points."

 

Thanks for your help.

 

[beast66606]

The answer is maybe.

 

In simple terms.

 

Having a starter

 

would allow shunt moves to take place without the token

 

not having one

 

would mean shunt moves would require the token

 

It is actually more complicated because if there was a starter then the home would need to be on the junction side of it, or an outer home would be needed otherwise a train could still depart from the junction and meet up with the shunt on the single line, without the protection of the (outer) home it is unlikely a starter would be provided.

 

A limit of shunt is not applicable on single lines - think of it as a signal fixed at danger, nothing can pass it, not even the normal trains ...

[The Stationmaster]

To go a bit further than Dave - firstly Company and BR Regional practice varied and also things changed over the years as well as depending on frequency of use etc. One school of thought was that an Advanced Starter should be provided in order to both limit shunt moves and indicate to the Driver that he didn't have permission to carry on through the section unless a running (Stop) signal was cleared for the movement. The other school of thought was that Drivers could be trusted not to charge off into the section so there was no need to waste money on an additional signal.

 

As to requiring a token in order to shunt there were again variations - for example on the Western (both Railway and Region) it was perfectly permissible to make shunts into a single line section from both ends at the same time so clearly a token could not be drawn to do that. Equally some other shunts didn't need a token depending on the Regulation under which they were made.

 

Equally there is no particular reason why an Outer Home would be needed 'on the other side' of the Advanced Starter - such situations were not uncommon and in reality are a consequence of the way Station Limits work at single line stations where they can be different in each direction and simply overlay each other depending on what is done in each direction. So if you provide an Advanced Start in one direction it isn't essential to provide an Outer Home in the other.

 

BTW the disc from the loop is in the wrong place - it should be at the toe of the point which leads to the coal siding as that point would act as a trap to stop errant moves out onto the running line. Also the signal for shunt moves below the Home Signal would likely be a ground disc but that depends very much on Company/Region and era.

 

Hope this lot helps a bit.

[signalmaintainer]

Beast and Stationmaster that helps very much. I was tempted to not go with the advance starter simply for the "it's how things were always done here" novelty. But modeling the commonly seen things is part of a good layout, and it will obviate awkward explanations later. So an advance starter will be implemented.

 

BTW the disc from the loop is in the wrong place - it should be at the toe of the point which leads to the coal siding as that point would act as a trap to stop errant moves out onto the running line. Also the signal for shunt moves below the Home Signal would likely be a ground disc but that depends very much on Company/Region and era.

 

You know, the placement of that loop disc signal has been bugging me for several months. I kept wanting to move it to the toe of the points, because that's where I'm used to seeing what we call "dwarf" signals here. But I was loathe to do so for fear it might be mistaken as a point indicator, not as it's intended purpose to authorize movement off of the passing loop.

 

Now I understand that not only should I move it, but why. Yet again, RMWeb serves to enlighten.

 

I like the idea of another ground disc for the goods siding. With Ettinsmoors' light railway roots, that gives me more latitude. Stop signal on, goods disc signal off, goods trains enters the siding!

[wagonman]

 

 

You know, the placement of that loop disc signal has been bugging me for several months. I kept wanting to move it to the toe of the points, because that's where I'm used to seeing what we call "dwarf" signals here. But I was loathe to do so for fear it might be mistaken as a point indicator, not as it's intended purpose to authorize movement off of the passing loop.

 

Now I understand that not only should I move it, but why. Yet again, RMWeb serves to enlighten.

 

I like the idea of another ground disc for the goods siding. With Ettinsmoors' light railway roots, that gives me more latitude. Stop signal on, goods disc signal off, goods trains enters the siding!

 

You could leave the disc where it is and insert an extra trap beyond it...

[signalmaintainer]

I see your point, and it's something to seriously consider. It might be simpler to move the signal, though. It's six of one, half-dozen of the other, as we say.

[Donw]

The answers make some sense but for a shunt move would the starter be plulled off because once that was off the driver could claim he had authority to proceed along the line. Alternatively the signalman could use a flag at the box to advise the driver. Obviously in practice everyone knew what was happening the goods would arrive and shunt probbaly leaving the van parked but once ready to go with the van on the end it would be clear this wasn't a shunt move. However I would have thought the BOT might not aprove of the arrangements? It would be nice to know as on a BLT pulling off the strater for propper departures only would make it clearer what was happening.

Don

[The Stationmaster]

The answers make some sense but for a shunt move would the starter be plulled off because once that was off the driver could claim he had authority to proceed along the line. Alternatively the signalman could use a flag at the box to advise the driver. Obviously in practice everyone knew what was happening the goods would arrive and shunt probbaly leaving the van parked but once ready to go with the van on the end it would be clear this wasn't a shunt move. However I would have thought the BOT might not aprove of the arrangements? It would be nice to know as on a BLT pulling off the strater for propper departures only would make it clearer what was happening.

Don

 

All depends on the authority under which the shunt move was to be made but if it was done as a Block Back (especially if there was already a train in the section (heading away from the terminus of course) then the Starter would not be cleared and the move would be carried out on the basis of 'a clear understanding' between Signalman and the person in charge of the movement and the latter would give the Driver a (shunting type of) handsignal to move.

 

But there were variations between Railways and BR Regions on this one although I 'm fairly sure without checking that none of them involved clearing the Starter. On a light railway of course things could be rather more 'relaxed' but I still doubt that the Starter would necessarily be cleared (but I think I've seen a pic where it was cleared on one light railway).

[Donw]

Thanks Mike. I would be grateful if you could clarify one other point. If there was an advanced starter would the starter be cleared for a shunt move or would it again be done by hand signal. I should really have paid more attention to all this but as a 14year old I never thought about these sort of things.

Don