Southern Railway / BR(S) Signal motors

[ikcdab]

I am building a bracket signal which has the distant for the next box beneath the starter. Southern / BR(S).

I intend to add a dummy Westinghouse signal motor to "work" the distant arm. Two questions:

1. I assume that the motor would be up on rhw doll in lieu of the balance arm rather than at the base of the post at ground level. Correct?

2. Despite having the signal motor, I will still need to work the arm mechanically from the servo beneath the baseboard. The prototype would not have had any mechanical linkages (presumably just a couple of electrical wires?) so how do folks operate these? As it's on a doll, I will need the usual cranks and wires/rods. I guess I just try and hide them behind the linkages for the mechanically worked starter?

Thanks

[bécasse]

Below is a drawing of the signal motor, a signal wire connects the (rotational) operating arm to the signal arm much in the same way as would be the case with a mechanically operated signal. There is a clip on Youtube showing the operation on an ER signal at 

[ikcdab]

39 minutes ago, bécasse said:

Below is a drawing of the signal motor, a signal wire connects the (rotational) operating arm to the signal arm much in the same way as would be the case with a mechanically operated signal. There is a clip on Youtube showing the operation on an ER signal at 

Thank you the drawing is very useful.

My question is that given that I have a servo under the baseboard, what's the best way of getting my non-prototypical mechanical linkage up to the arm without it looking ridiculous. 

[bécasse]

With the exception of tunnel distants which, as banner signals, were a totally different "kettle of fish", all the combined starting and distant signals that I can remember on the Southern where the distant was motor worked had the starting signal motor worked as well. I can't see how the slotting would work if this were not the case. In both cases the motor would have been mounted, say, a clear foot below the respective arm - on the doll if it was a bracket signal.

 

I am not sure how you would route (hide) the operating wires from the servo, it is one of standard dilemmas of modelling.

[ikcdab]

1 hour ago, bécasse said:

With the exception of tunnel distants which, as banner signals, were a totally different "kettle of fish", all the combined starting and distant signals that I can remember on the Southern where the distant was motor worked had the starting signal motor worked as well. I can't see how the slotting would work if this were not the case. In both cases the motor would have been mounted, say, a clear foot below the respective arm - on the doll if it was a bracket signal.

 

I am not sure how you would route (hide) the operating wires from the servo, it is one of standard dilemmas of modelling.

Maybe the southern was very enlightened. I found the following quote by Graham Warburton talking about the LMS:

 "Stenson Junction Home signals looking towards Derby on 15th March 1950.  The splitting distant arm is in use.  The stop arm is mechanically worked with the distant arms operated by British Railway Signal Company electric motors due to the necessary ‘backslotting’ required by the various stop signals ahead.  A. F. Bound (the S&T Engineer) insisted that motor worked distant signals must be mechanically slotted (at the top of the main stem) to ensure the arm does not stick in the ‘Off’ position with the top arm ‘On’. "

[The Stationmaster]

On Aylesford's Up Starting Signal the motor was in fact part way along the landing on top of the bracket (roughly central)  and drove the counter balance weight arm (which had no balance weight on it) for the distant signal arm.  But the distant arm in that case wasn't very far above the level of the landing so there was obviously no room to mount the motor in any other way.  In that case there was no mechanical slotting between the stop and distant arms.  The same applied on another,  straight post, signal signal in that area although on it  - a tall, lattice post signal - the motor was part way up the post and the distant arm balance weight lever still had a weight on it (probably to make sure it went back properly so it wasn't slowly going back to caution when the stop arm above it was going back more quickly).  In the case of both these signal the stop arm does not appear to have been motor worked and only one motor is visible on the signal structure.

[iands]

Although not BR(S) territory, and not a bracket signal, these photos are from Sleaford (BR(E)). The top (Stop) arm is Sleaford West's 5 signal, direct signal wire from the 'box, and the distant arm is Sleaford East's 2 signal, with signal motor operating the mechanical slotting. I also attach a diagram that might be of use that shows how the slotting works, albeit not via a signal motor but the principle is still the same.

 

 

 

Slotted Signal.pdf

 

[bécasse]

Sorry, I was slightly mislead by the favoured location of my youthful (and somewhat green) spotting days, the main line footbridge at the south end of Hither Green station which had two starting/distant pairs mounted on it, all of which were motor worked - it took me some months to work out where the regular "whirring" noises came from!

 

Of course the Southern had motor-worked distants mounted below wire-worked stop arms - however, there was no mechanical slotting but a switch worked in tandem with the stop arm which cut the power to the distant arm whenever the stop arm was on, thus ensuring that the distant couldn't be (powered) off when the stop signal was on. As Mike has rightly pointed out weights could be added to aid the speedy return of the distant arm to the horizontal if necessary - all four of those signals at Hither Green moved quite slowly whether being pulled off or returning on but at least they did the latter in tandem.

 

The measured motor, incidentally, was situated at Shanklin even though it was actually Sandown's up home!

[Steve Hewitt]

On 22/06/2020 at 08:59, ikcdab said:

I am building a bracket signal which has the distant for the next box beneath the starter. Southern / BR(S).

I intend to add a dummy Westinghouse signal motor to "work" the distant arm. Two questions:

1. I assume that the motor would be up on rhw doll in lieu of the balance arm rather than at the base of the post at ground level. Correct?

2. Despite having the signal motor, I will still need to work the arm mechanically from the servo beneath the baseboard. The prototype would not have had any mechanical linkages (presumably just a couple of electrical wires?) so how do folks operate these? As it's on a doll, I will need the usual cranks and wires/rods. I guess I just try and hide them behind the linkages for the mechanically worked starter?

Thanks

 

 

Hi ikcdab,

 

I have used Westinghouse Backing Machines on one or two signal models, trying to keep the operating linkages hidden from view.

If you go to my Topic the following post will eventually try to answer your question.  Hope this is helpful.

 

Steve.

 

[ikcdab]

10 hours ago, Steve Hewitt said:

 

 

Hi ikcdab,

 

I have used Westinghouse Backing Machines on one or two signal models, trying to keep the operating linkages hidden from view.

If you go to my Topic the following post will eventually try to answer your question.  Hope this is helpful.

 

Steve.

 

Hi Steve, many thanks. I do follow your thread but missed this part!

Regards 

Ian