Point rodding and signal wires

[Compound2632]

26 minutes ago, Nick C said:

There would probably alos be locking bars on the FPLs, so, as I understand it, the FPL rods would go to the far end of the locking bar, and the near end would be linked to the FPL itself.

 

Thanks, that's a point (if you will pardon the expression) I hadn't appreciated. With Peco code 75, the locking bars will probably be imaginary, but there's no reason the rodding shouldn't be represented. There might need to be a bit of discreet foreshortening! 

 

Also, operators will have to be trained (again, pardon me) to draw sufficiently far back from the point to be clear of the imaginary locking bar. The rodding will serve as a marker.

[Michael Hodgson]

1 minute ago, Compound2632 said:

 

Thanks, that's a point (if you will pardon the expression) I hadn't appreciated. With Peco code 75, the locking bars will probably be imaginary, but there's no reason the rodding shouldn't be represented. There might need to be a bit of discreet foreshortening! 

 

Also, operators will have to be trained (again, pardon me) to draw sufficiently far back from the point to be clear of the imaginary locking bar. The rodding will serve as a marker.

That usually means far enough to clear the shunt signal to come back again.

A length of point rodding isn't far off as an approximation of a mechanical locking bar, glued in lowered position so as to clear flanges.

[Compound2632]

5 minutes ago, Michael Hodgson said:

That usually means far enough to clear the shunt signal to come back again.

 

That's alright, I'm just one step ahead of the signal-planter. Negotiations will take place!

[5BarVT]

4 hours ago, Michael Hodgson said:

That usually means far enough to clear the shunt signal to come back again.

Generally (covering my options!) shunt signals would be at a trailing Xover so no need for an FPL.

4 hours ago, Compound2632 said:

 

That's alright, I'm just one step ahead of the signal-planter. Negotiations will take place!

Main (running) signals would normally be set back to give room for the locking bar before the points, but if not then the locking bar(s) would be on the blades.  See photos of Helston for a single bar on point blades, if passenger routed both ways then one bar on each blade.

Paul.
 

[Compound2632]

1 hour ago, 5BarVT said:

Generally (covering my options!) shunt signals would be at a trailing Xover so no need for an FPL.

 

I described the layout above but will repeat that it's a goods loop off a single running line. Both crossovers are therefore facing for one direction of travel and trailing for one. Therefore both need FPLs. The intention is that moves from the running line into the loop are controlled by ground signals. (Which will be non-functional!) This is because the running line semaphores are the Dapol ones, which do not feature a running line-to-loop miniature arm. (Such could be added from the Ratio kit, for example, but a non-functioning ground signal is less obtrusive than a non-functioning semaphore.)

[5BarVT]

Apologies, hadn’t gone that far back.  As you can see, I was thinking double track.

I can understand your wanting to use shunt signals as there is no readily available RTR signal.  I was puzzled why I couldn’t think of any example of your layout of locking bar between shunt signal and points: now I can see it’s because it would never be done that way in real life - it adds an extra lever as there would need to be a shunt signal at the home signal the read up to the shunt at the points.  More expensive to install and more expensive to operate as more lever pulls equals higher grade.

So, going back to your layout: there is a modern semaphore solution that would work and that is with the home signal as you would expect near the loop points with a shunt signal at its base to read into the goods loop.  Having said that, somewhere at the back of my mind I think I might have seen a photo of a (G)WR signal with an elevated shunt signal on a small bracket off the main post.  If that is so, you could model that with a Dapol main arm (straight post) and a non working shunt signal on a ratio or similar small bracket attached to it.

If this is solving a problem you don’t have, feel free to ignore completely!

Paul.

[bécasse]

13 hours ago, 5BarVT said:

 

So, going back to your layout: there is a modern semaphore solution that would work and that is with the home signal as you would expect near the loop points with a shunt signal at its base to read into the goods loop.  Having said that, somewhere at the back of my mind I think I might have seen a photo of a (G)WR signal with an elevated shunt signal on a small bracket off the main post.  If that is so, you could model that with a Dapol main arm (straight post) and a non working shunt signal on a ratio or similar small bracket attached to it.

Uxbridge Vine Street had one (for "departing" trains) but it was a WR solution when a former GWR bracket signal was replaced, the bracket signal had used a "wrong road" arm (with two holes in it) for the same move.

[The Stationmaster]

Right - there are several ways to do teh signalling - depending on the period being modelled and the longevity of certain earlier ways of doing the job plus the way in which the goods loop is regarded.

 

But first in case it might help here is an official GWR sketch of the arrangement of the roffdding and drives at a facing point which doesn't have an economical FPL.

 

 

 

Now the signalling and this si something which changed over the years and depended on the category of the lines involved.  the main running line is the simplest bit as it of cpourse is a passenger line so would have ordinary semaphore signals with the arm length dependent on the height of the arm above rail level but basicall a 4 foot long arm in most cases in the era of timber posts because a tall signal was uncommon in such situations and inevitably a 4 ft arm with a tubular steel post (except the very early ones some of which had timber arms).

 

The next thing to address is teh category of the kine forming a loop.  If it is a Goods Loop and thus likely to be used to allow a freight to be looped for a passenger train to pass it then a semaphore signal would be used to read to it - in any era including right into and beyond BR WR days.  But the form/way in which this was done varied over the years.   The arrangement shown below, with a centre pivot arm on a small bracket off the main signal post was the standard arrangement to read to a goods Loop, or siding from the late 19th century until around the time WWI but was officially noted as 'the old method' in 1920.  Such signals survived in some places for many years the strangest of these being one at Slough Middle which lasted into the early 1960s with the arm/small bracket transferred at the time of a 1950s signal renewal to a new tubular steel post - probably unique?   But photos indicate that the arrangement was still to be seen well into the 1930s and in some cases in post WWII years

 

Ignore the Shunt Ahead arm on the signal in the photo below - nothing to do with anything you need.

 

 

This arrangement was supseded by an ordinary bracket signal with a 3 ft arm reading to the goods loop or siding.  Examples of this arrangement may well still be found and the situation of such an arrangement with the 3ft arm leading to a siding definitely survived into the early 1970s although it was very unusual by then.

 

The next change came - according to photos, from around the latter part of the 1930s and applied if the splitting signal read to a siding.  This was to use a disc - sometimes elevated in some way or another -  instead of the 3ft semaphore arm.  However if the disc was used solely for a propelled shunting movement back into the siding or loop it would be ground mounted - and this was by far the most common arrangemnt.

 

Of course if the loop is a Goods Loop used to cross the trains then a semaphore would be provided reading from it.  This would usually be a 3ft arm witha ring on it (see photo below) and these could still be seen well in to the 1960s anda few later although new installation ceased from January 1950.  A semaphore would also be used at the exit from a siding if trains started away from that siding.

 

 

 

[Compound2632]

18 hours ago, 5BarVT said:

So, going back to your layout: there is a modern semaphore solution that would work and that is with the home signal as you would expect near the loop points with a shunt signal at its base to read into the goods loop.  Having said that, somewhere at the back of my mind I think I might have seen a photo of a (G)WR signal with an elevated shunt signal on a small bracket off the main post.  If that is so, you could model that with a Dapol main arm (straight post) and a non working shunt signal on a ratio or similar small bracket attached to it.

 

4 hours ago, The Stationmaster said:

But first in case it might help here is an official GWR sketch of the arrangement of the roffdding and drives at a facing point which doesn't have an economical FPL.

 

The next change came - according to photos, from around the latter part of the 1930s and applied if the splitting signal read to a siding.  This was to use a disc - sometimes elevated in some way or another -  instead of the 3ft semaphore arm.  However if the disc was used solely for a propelled shunting movement back into the siding or loop it would be ground mounted - and this was by far the most common arrangemnt.

 

Thank you both; some very helpful stuff here. I shall report back to the Chief Engineer.

 

Although a block post, Erlegh Quay is not set up for passing trains. The loop is not intended to be set up to allow arrivals directly into it or departures from it. It serves a pair of exchange sidings with a private line. It also currently provides a run-round loop; this function will be less important once our fourth board is added, providing a fiddle yard at both ends of the layout. 

 

If I have understood you both correctly, for 1955 the ground-mounted disc at the foot of the home is an authentic solution. There is a problem with this at one end of the loop, where the home is mounted on the platform end (the passenger platform is beyond, not alongside, the loop); here a bracket-mounted disc appears to be the solution, again, if I have understood correctly. 

 

Mike, many thanks for the FPL drawing. I'll have a play around to see how this can be represented using Peco code 75 points and Wills rodding!

[The Stationmaster]

28 minutes ago, Compound2632 said:

 

 

Thank you both; some very helpful stuff here. I shall report back to the Chief Engineer.

 

Although a block post, Erlegh Quay is not set up for passing trains. The loop is not intended to be set up to allow arrivals directly into it or departures from it. It serves a pair of exchange sidings with a private line. It also currently provides a run-round loop; this function will be less important once our fourth board is added, providing a fiddle yard at both ends of the layout. 

 

If I have understood you both correctly, for 1955 the ground-mounted disc at the foot of the home is an authentic solution. There is a problem with this at one end of the loop, where the home is mounted on the platform end (the passenger platform is beyond, not alongside, the loop); here a bracket-mounted disc appears to be the solution, again, if I have understood correctly. 

 

Mike, many thanks for the FPL drawing. I'll have a play around to see how this can be represented using Peco code 75 points and Wills rodding!

To be honest I wouldn't use Wills rodding if you have the choice - for two reasons.  Firstly it is overscale for 4mm and secondly it is very noticeably not Western rodding (if you happen to know the difference - although I suspect that most people don't)

 

A co-located disc at ground level would be perfectly acceptable at both locations  -  like this

 

[Compound2632]

8 minutes ago, The Stationmaster said:

To be honest I wouldn't use Wills rodding if you have the choice - for two reasons.  Firstly it is overscale for 4mm and secondly it is very noticeably not Western rodding (if you happen to know the difference - although I suspect that most people don't)

 

It's what we've got in hand - needs must...

 

9 minutes ago, The Stationmaster said:

 

Now a wrong-side signal would solve more than one problem. Another idea to submit to the Chief Engineer. 

 

Where is the locking bar?

[RailWest]

40 minutes ago, Compound2632 said:

 

 

Where is the locking bar?

It's track-circuited, so the 'train detection' is electrical rather than mechanical :-)

[Compound2632]

22 minutes ago, RailWest said:

It's track-circuited, so the 'train detection' is electrical rather than mechanical :-)

 

Doh - there's a prominent lozenge on the signal post!

[RailWest]

On 07/04/2023 at 18:05, Compound2632 said:

 

Doh - there's a prominent lozenge on the signal post!

Actually, that is irrelevant :-)

 

The 'Rule 55' diamond exists because a train standing at the signal is detected by track-circuit ACT in rear of that signal. The FPL and point are detected by TC ABT, which is in advance of the signal.

Edited May 5, 2023 by RailWest

[Phil Bullock]

I wonder if the forum can help with advice on what is going on with the rodding on the ground in the 6ft on the up side here please? Looks like the facing point and fpl are slotted with the wires to the up home signals for the junction which are behind the photographer …. But I wonder why that would not be done using the interlocking on the frame in the box?

 

Thanks in advance….

[RailWest]

That will be the detection.

The interlocking in the frame is only capable of ensuring that you can pull the right lever for the right signal depending on the position of the point and FPL levers. The detection ensure that the points blades are actually properly closed and the FPL plunger is full in.

[Phil Bullock]

27 minutes ago, RailWest said:

That will be the detection.

The interlocking in the frame is only capable of ensuring that you can pull the right lever for the right signal depending on the position of the point and FPL levers. The detection ensure that the points blades are actually properly closed and the FPL plunger is full in.

Ah thank you! So there would be a slide for each signal wire that can only move to clear when the FPL is fully home? I did then wonder, as the FPL would be in the same home position for both routes,  how the appropriate signal would be unlocked but of course that would be done by the interlocking on the frame in the box. 

[RailWest]

Basically yes. FPL bolt proved 'in', the 'closed' switch rail proved closed and also the 'open' switch rail proved open. The relative position of the latter two slides governs which of the two signal slides can move.

[Phil Bullock]

37 minutes ago, RailWest said:

Basically yes. FPL bolt proved 'in', the 'closed' switch rail proved closed and also the 'open' switch rail proved open. The relative position of the latter two slides governs which of the two signal slides can move.

Thanks that’s very useful

[The Stationmaster]

Thus is a Wesrten detector arranged in the Western manner and in this case it will once commissioned (it is now) be detecting a facing point for two ground disc so ignore the temporary hand lever working the points.

 

3 rods to the detector one each for the point switch rails and one of the FPL then one slide for each signal wire run.  To get the detection proved the notches in the three rods from the switch rails and FPL have to align with the notch in the slide in the wore run.  If they don't line up then the point will be not be detected as correctly set with the switch closed and boltred by the FPL'

 

Edited May 8, 2023 by The Stationmaster
Typos corrected. Strange how they didn't show when reading through before posting!!

[RailWest]

I think the keys on your keyboard could do with a bit of 'detection' too :-) :-)  Or is that the Western vernacular creeping in.....

[Phil Bullock]

53 minutes ago, The Stationmaster said:

Thus is a Wesrten detector arranged in the Western manner and in this case it will once commissioned (it is now) be detecting a facimng poinyt for two ground disc so ignore the temporary hand lever working the points.

 

3 rods to the detector one each for the point switch rails and one of the FPL then one slide for each signal wire run.  To fget teh detection proved the notches in the three rods from the switch rails and FPL jab ve to alingn with the notch in the slifde in the wore run.  If they don't line up then the point will be not be detected as correctly set with the switch closed and boltred by the FPL'

 

Thanks Mike that’s how I envisaged… been to Severn Valley today, hoped to get a photo but yours certainly does the job…

[DavidBird]

On 07/05/2023 at 19:08, The Stationmaster said:

Thus is a Wesrten detector arranged in the Western manner and in this case it will once commissioned (it is now) be detecting a facing point for two ground disc so ignore the temporary hand lever working the points.

 

3 rods to the detector one each for the point switch rails and one of the FPL then one slide for each signal wire run.  To get the detection proved the notches in the three rods from the switch rails and FPL have to align with the notch in the slide in the wore run.  If they don't line up then the point will be not be detected as correctly set with the switch closed and boltred by the FPL'

 

The ones that I've had a chance to look at closely on my "local" heritage railway - The Strathspey Railway - are presumably LMS/Br(sc) designs.  The frame that holds the signal slides is mounted on a fixed base by slots that allow it to move at right angles to the track.  There is a fourth rod that secures the frame a fixed distance from the running rail, and so automatically compensates for heat expansion in the detector rods themselves.  I'll post a photo when I can find it.

[RailWest]

But...you can still go from St Erth to St Ives (and back again) :-)

 

[The Stationmaster]

On 12/05/2023 at 15:10, RailWest said:

But...you can still go from St Erth to St Ives (and back again) :-)

 

And there's still some point rodding at St Erth.  

 

Plus a delectable signal wire run along the face wall of the Down Main platform.