Help with Location of Home Signal

[peach james]

OK, here goes:

 

I have a facing point, which will have a home signal located to its rear on the main line. How far back must the signal go? I know it must be before the fouling point, but how much before that would it be?

 

I'm assuming there was a BoT rule for how far it had to be- if it helps, Midland Railway/Settle & Carlisle/Long Marton, and no, the signal is NOT shown for location on the 25"/mile maps.

 

Thanks,

James Powell

[phil-b259]

I have a facing point, which will have a home signal located to its rear on the main line.

 

When you say home signal are you talking about the signal marking the end of the 'block' section between signals or home as opposed to a distant signal. I ask because many people incorrectly describe any red armed semaphore signal as a home signal when the proper designation of the red arm is a 'stop signal??™ and the designation 'home' has a specific meaning in signalling terms.

 

How far back must the signal go? I know it must be before the fouling point, but how much before that would it be?

 

The distance you are talking about (known as the overlap in professional terms) is, and has been for quite a while, 200yards. However as usual with the railway there are exceptions, usually where the maximum speed of an approaching train has been reduced to a low figure. This can be either by the use of a permanent speed restriction or by the signalman applying the approach control rule (number 39a in the rulebook) to trains required to stop at the signal. In both these situations overlaps of 50 yards or less can be provided although this is usually on the approach to large stations, etc. The thing is its perfectly feasible for points, including facing ones, to be included in the overlap of a signal. The only requirement is that any points within an overlap must be set correctly to provide the required overlap distance before the preceding signal can be cleared (which will lock the aforementioned points and protect the overlap). Hence the question about the signal type. If it is a true 'home' signal then there is no preceding signal and you must represent the full 200yard overlap to the fouling point as this will be the first stop signal a driver will encounter when entering the control of a signal box. If on the other hand it is merely a stop signal within the area controlled by a signal box you can get away with a reduced overlap and move the signal closer to the fouling point.

[Edwin_m]

You can have a stop signal as close to a facing point as you like. If it is the home signal then the overlap can continue over the point - obviously the point has to be correctly set and the line beyond it needs to be clear as far as the clearing point before a train can approach. If the point is very close to the signal then it will be locked as the train approaches, in case it overruns the signal.

 

Clearing point is traditionally 440 yards beyond the stop signal and remains so when the distant is a semaphore, but under current rules can be reduced to 200 yards with a colour light distant. I don't know when this relaxation came in though.

[beast66606]

As Edwin has (almost) said, a home 1 (the normal nomenclature for the first stop signal) can be as close to a facing set of points as you like, however the points must be set and locked for one of the routes before a line clear can be given if the points fall within the overlap (440 / 200 yards) - effectively before a train can approach from the previous signal box - and should not be moved (of course they never were ) again until the train has come to a stand.

 

Quite often an additional home signal was provided (this would be the home 1 and the one descibed above would be the home 2, sometimes called the outer and inner homes) on the approach to the facing junction, some 440 yards away, to facilitate working, this meant a train could be accepted from the box in rear, no matter which way the junction was set, and the junction could be swung for other traffic as required.

 

Even on power box controlled colour lights the same rules apply however the overlap is considered to be "swinging" - as in the points can be set either way until the train reaches the previous signal, and then they are held in whatever the final position was, until the train has come to a stand (normally meaning occupies a certain track circuit for a certain length of time).

 

 

Hope this all makes sense, if not ask again and I will do some of my wonderful sketches

[Guest stuartp]

"Stations and Structures of the Settle & Carlisle Railway" by Anderson and Fox shows the Up Home to be opposite the Newbiggin end of the trailing crossover on the main line, and the Down Home to be opposite the Settle end of the crossover in the goods yard. The diagram is dated 1961.

 

There aren't any facing points on the main line though, it's a classic MR 'everybody must set back through trailing points' layout.

 

Edit (my sketch after Anderson & Fox):

 

[flyingsignalman]

Just to muddy the waters a little

Facing points in the overlap could (and still can) be altered for another route provided the overlap was still available in that alternative route, unless obviously the signals had already been cleared for an approaching train. If the facing points required to be altered (for flank protection) and the overlap was not available in the alternate route then various signalling rules and regulations had to be applied before the points were moved.

 

Trailing points in the overlap, however, cannot be moved once a train has been accepted.

[The Stationmaster]

Just to muddy the waters a little

Facing points in the overlap could (and still can) be altered for another route provided the overlap was still available in that alternative route, unless obviously the signals had already been cleared for an approaching train.

 

(and even muddier) except under GWR Regs which absolutely forbade movement of facing points within the Clearing Point after a train had been accepted unless/until it had been brought to a stand at the Home Signal.

 

But the original query was not about the GWR of course

[beast66606]

Edit (my sketch after Anderson & Fox):

 

To be picky (and not connected to this thread!) Stuart - the distants have an auxilliary yellow (for failure) rather than a capability to show a double yellow aspect (which is what your diagram implies, this may have come from the book of course)

 

 

Facing points in the overlap could (and still can) be altered for another route provided the overlap was still available in that alternative route,

 

Known as swinging overlaps as I described (simplified granted) above

[micknich2003]

Rule 39a, you are going back a bit. The old "Black Book" was done away with close on 40 years ago. Best Wishes, Mick Nicholson.

[The Stationmaster]

Rule 39a, you are going back a bit. The old "Black Book" was done away with close on 40 years ago. Best Wishes, Mick Nicholson.

 

And some of us had to learn all the new blinkin' numbers and cross references

[Guest stuartp]

To be picky (and not connected to this thread!) Stuart - the distants have an auxilliary yellow (for failure) rather than a capability to show a double yellow aspect (which is what your diagram implies, this may have come from the book of course)

 

Sorry, I copied it down in a bit of a rush, the diagram does actually say 'AUX' next to each of the distants.

[beast66606]

Sorry, I copied it down in a bit of a rush, the diagram does actually say 'AUX' next to each of the distants.

 

Not being awkward but those who don't know better treat these things as gospel - hope you didn't mind

 

Sorry for the wandering

[Guest stuartp]

hope you didn't mind

 

Not at all. I'm slightly annoyed with myself that it didn't register as not quite right when I was drawing it - it should have registered that they couldn't be 3-aspects ! Mind you, I was being nattered at to go to the sales at the time ("Are you going to be much longer on that thing ?").

 

I'm curious as to which facing points the OP was referring to on this particular layout, unless the appearance of the No. 6/7 single slip on the 25" map is misleading.

[peach james]

This should teach me to post at 12 pm at night...

 

1. It's a trailing point, not facing. Doh!

 

2. I am aware that what modelers call a home signal may not be what the railway describes it as. (Turnout vs Track Switch...)

 

3. I really need to get a copy of "Stations & Structures of the S&C". Unfortuately, it isn't like in the UK, where I could order one up to-day and get it tomorrow . I've had it in my shopping basket a couple of times...but never bought it. Mostly, it is the shipping cost...

 

On the diagram, it is the stop signal protecting turnout 6b. I guessed wrong- and have it on the other side of the signalbox. The OS map shows some of the signals, I knew there were problems with the location of them from it...and it shows one about 10 yds from 6b on the 1916 map. I guessed wrong...now to dig out the Torti, and the signal.

 

Thank you all for you help.

 

James Powell