Exiting private sidings

[cromptonnut]

Hi all

 

A quick and hopefully simple question if I may.

 

Layout consists of a single "main line", with a point coming off into a private siding, fairly standard 2 sidings and a small headshunt plan which I don't think needs reproducing here.

 

On the exit of the private sidings on to the main line, would it be a ground position signal to proceed on to the main line, or would a "normal" 2 or 3 aspect signal be used?

 

Set in the 1970's/1980's, south west UK if that makes a difference.

 

Many thanks

 

'Nut

[TheSignalEngineer]

Depends on whether the siding is worked by the box or a ground frame. What is the method of working on the line? 

[cromptonnut]

There will be a signalbox very close to the point that controls the entrance to the siding - so I would normally take it to be box controlled?

[flyingsignalman]

I would think a ground position light signal would be most probable as most moves from the siding would be shunts.

[The Stationmaster]

Depends on whether the siding is worked by the box or a ground frame. What is the method of working on the line? 

 

Also de[ends on whether it will be a 'train movement' departing or a shunt (see Flying Signalman's comment) and the answer then could be influenced by other signals in the area and the era you are modelling.  However the answer for your chosen era and area is ground position light.

[Edwin_m]

If there is a headshunt then I think you are looking at either back to back ground position lights (set permanently "off" for shunting) or in a slightly older installation a yellow GPL. 

[bécasse]

Your original question says:

"Layout consists of a single "main line", with a point coming off into a private siding, fairly standard 2 sidings and a small headshunt plan which I don't think needs reproducing here."

 

Given that you also state that the layout is set in the 1970s or 80s and in the south west, the simple answer is that there would NOT have been ANY signals linked to access to or departure from the siding.

 

Even with a signal box nearby, access to the siding would have been controlled by the mechanism used to control access to the single line. In this location and era, this would have most likely been an electric key token (EKT) although train circuit block (TCB) or even direction lever (DL) wouldn't have been impossible. If the signal box controlled the siding access then that would have been physically linked with the loop that the box controlled and not with the single line itself.

 

​The point would have been worked by a traditional (and very simple) GWR/WR 2-lever ground frame. One lever painted blue would have been released either physically by the EKT or electrically from the box (TCB/DL) and would have worked the facing point lock, the other lever painted black would have worked the points themselves. There would have been NO fixed signals, the person working the ground frame giving the necessary hand signals to the loco crew.

 

This was a very standard arrangement on the former GWR, with examples dating back to at least the earliest years of the 20th century, and with the WR finally taking over the ex-LSWR lines in the south west in 1963, it rapidly became the standard arrangement on those (substantially rationalised) lines too.

[cromptonnut]

Not even a signal with feather or call-on on the main to tell the driver to proceed, with a phone to call the box?

[beast66606]

Not even a signal with feather or call-on on the main to tell the driver to proceed, with a phone to call the box?

 

Perhaps you need to post a plan to clarify - do you mean a single line, or a single line of double track ?

[cromptonnut]

Ok might as well go for the full signalling if I'm going to do it   Here's a rudimentary version of the plan.

 

Black line is the bi-directional main line which extends off-scene in both directions.  The black square is a station platform.

 

The red bit is the "private sidings".  Main line loco enters with train, sidings shunter removes wagons to release loco, loco couples to wagons in other siding, takes them away.  Shunter shuffles wagons from empty to full, rinse repeat.

 

 

I envisage colour light signals although am not adverse to a semaphore if necesssary.

[beast66606]

Ground frame and no signals is the most likely in that circumstance I'm afraid.

[cromptonnut]

I assume at the end of the station platform near the point there'd be a signal with a call-on for reversing into the sidings?

[beast66606]

I assume at the end of the station platform near the point there'd be a signal with a call-on for reversing into the sidings?

 

No need for any signals (as bécasse says) - all done by waves and whistles.

[cromptonnut]

What if there was no signalbox there?

[PatB]

What if there was no signalbox there?

 

Whilst I'm not an expert, I'd agree with Beast. Bridgwater goods yard/nuclear flask loading point has (or used to have; I've not been there for a loooong time) a facing connection with the up main line controled by a ground frame which (I assume) is unlocked from the relevant box which is I don't know where but certainly nowhere near Bridgwater (Bristol? Taunton?). From memory there are no signals directly related to the siding connection, although the ground frame lock will obviously be interlocked with the main line signals to prevent conflicting movements.

[cromptonnut]

I was just thinking that ground frame operation and hand signals don't translate too well to model form, so if removing a signalbox meant I could have a couple of signals that "did something" it would at least give the impression of something more happening.

[PatB]

I was just thinking that ground frame operation and hand signals don't translate too well to model form, so if removing a signalbox meant I could have a couple of signals that "did something" it would at least give the impression of something more happening.

 

I agree completely that the prototype is extremely unobliging, insisting as they do on doing things the economical way rather than the most modelogenic way .

 

Personally I liked the suggestion of a ground signal. Working ground position lights would be a relatively unusual detail and could be a nice talking point. I don't see anything wrong with going for a solution which is technically feasible/correct even if it would be unusual on the prototype for economic reasons. Maybe your (presumably freelance) location is subject to special circumstances which make the installation of fixed signals appropriate.

[Rivercider]

Whilst I'm not an expert, I'd agree with Beast. Bridgwater goods yard/nuclear flask loading point has (or used to have; I've not been there for a loooong time) a facing connection with the up main line controled by a ground frame which (I assume) is unlocked from the relevant box which is I don't know where but certainly nowhere near Bridgwater (Bristol? Taunton?). From memory there are no signals directly related to the siding connection, although the ground frame lock will obviously be interlocked with the main line signals to prevent conflicting movements.

Bristol PSB is the controlling box, there was a GPL controlling exit from the yard, it is visible in some of the shots on my Flickr collection,

also a GPL on the same post as the starter on the up platform giving access into the yard.

In the Bridgwater area there were other ground frames. One to the west end of the station controlling access to the RSD sidings via a trailing connection off the up main.

Towards Bristol a ground frame controlled entry into British Cellophane/Courtaulds, a trailing connection off the down main.

At Huntspill a ground frame controlled the facing entry off the down main to the ROF Puriton and a main line crossover, I think there was a limit of shunt signal on the down line towards Bristol,

 

cheers

[cromptonnut]

Personally I liked the suggestion of a ground signal. Working ground position lights would be a relatively unusual detail and could be a nice talking point. I don't see anything wrong with going for a solution which is technically feasible/correct even if it would be unusual on the prototype for economic reasons. Maybe your (presumably freelance) location is subject to special circumstances which make the installation of fixed signals appropriate.

 Working in 7mm makes such things much more "doable". 

 

Absolute Aspects do a working 7mm colour ground signal https://www.absoluteaspects.com/index.php/product-range/ground-position-signals and MSE do the mechanical type http://www.modelsignals.com/7mm_scale_frame.htm

 

You are right, it's a freelance location and no doubt there are circumstances where "non standard" implementations of signals were required - but I'd still like to have it grounded in reality rather than "what would look good in model form".

 

 

Perhaps, as I am in the early stages of construction, I could "engineer in" one of these "special circumstances" of which you speak... what sort of things?

 

Thanks to all for the help so far, signalling is an area I have not yet researched as much as I should have.

[TheSignalEngineer]

What traffic levels are you looking at, how frequent are main line trains and is it a daily service to the siding? 

 

The margin available between trains may have a bearing on how things are done.

 

If all else fails, Rule 1 applies.

[cromptonnut]

Being a secondary line I'd guess hourly or two-hourly DMU in each direction with the occasional inbetween train (model representations to the timetable minute are rarely exciting).

 

To the siding, possibly 2 or 3 times a week but of course that would be in "condensed time" otherwise it would be fairly tedious to operate!

 

There would be plenty of time between scheduled services for any movements between the mainline and sidings without interfering with the timetable - and, of course, the little diesel shunter in the yard would do work inbetween.

 

Rule 1 is very handy of course

[TheSignalEngineer]

The service points to ground frame operation with no signals.   

 

Rule 1 may have to take precedence.

[RailWest]

I would agree that the most likely scenario for the location and date would be a GF with no signals.

 

>>>"The point would have been worked by a traditional (and very simple) GWR/WR 2-lever ground frame.......and with the WR finally taking over the ex-LSWR lines in the south west in 1963, it rapidly became the standard arrangement on those (substantially rationalised) lines too."

 

True, but.....when the BR(S) S&T started to get their hands back on much of the line to Exeter again, I gather that they started to rmeove the WR GFs and replace them by SR 'knee' types :-)

[Steven B]

The service points to ground frame operation with no signals.   

 

Rule 1 may have to take precedence.

 

You could always animate the ground frame rather than the signal! A pair of servos should allow you to make both levers appear to work.

 

Happy modelling.

 

Steven B.

[bécasse]

Steven B. suggested that "you could always animate the ground frame rather than the signal! A pair of servos should allow you to make both levers appear to work."

 

In fact, you could go further than that and make the fpl pull out when the blue lever went over - it wouldn't be difficult to do, and would be quite visible, in 7mm scale. I would suggest that might be more interesting than a ground signal changing.

 

The sequence of events when it was necessary to use the siding would be that the Electric Key Token would be inserted in the lock attached to the frame and turned - this would release the frame but lock the EKT in the lock. The blue fpl lever would be pulled first, releasing the facing point lock, and then the black point lever reversing the points (which are effectively a "crossover") for access to and from the siding. When the siding had been shunted the whole process would be reversed to restore normal single line working on the main line. If the shunting required it, the points could be reversed and re-reversed as often as required during the actual shunting operation by operating the black lever - but it is very unlikely that the fpl would be replaced until the whole job was finished. Old fashioned railwaymen always knew the easiest way to do a job - and never did more than was essential.

 

If you scroll well down on this page: http://forum.signalbox.org/viewtopic.php?f=2&t=6262, you will come to a picture of a typical ex-GWR 2-lever ground frame at Pontsmill. There was at least one other type which was identical in function and similar in general appearance but which differed in detail.