A layout shunt signal question

[Kylestrome]

I would like to know if my shunt signal positioning is plausible or totally wrong!

 

The layout in question sort of ‘evolved’ from one thing to something completely different, which explains the somewhat unconventional track layout. What started life as an urban goods yard has morphed into a single-platform branchline station on an ex-light railway in the West Highlands. Bear in mind, this is not a GWR station were every possible move would have a signal provided. I have looked at a number of West Highland Line stations and they seem to be provided with absolute minimum of shunt signals.

 

So what do you think – can I leave it like this or is what I’ve done complete nonsense?

 

 

[MarcD]

If its a light railway you could get away with running one engine in steam and get rid of all the signals. Having said that the position of the signals look about correct for a branch-line. However different companies had subtle differences.

 

Marc

[RailWest]

I would suggest that the two Starters should be at the ends of the platform.

 

The point on the goods siding/loading bank line will need to act as a trap-point to protect the main running line, so the shunt on the exit from that siding will need to be in rear of that point as currently there is no trap between it and the main line. Alternatively, make the point leading into that siding a hand-point, make the aforementioned point on the siding work from the same lever as the loop trap, and have just one shunt situated between the loop and the siding to control both exits. But they may have done things differently up north....

[Kylestrome]

Many thanks for the replies.

 

If I put a shunt signal before the yard points, as suggested, can I assume that these points will also have to be controlled from the signal box? Up until now I had thought of them as being operated on the ground by a shunter.

 

I’ve modified the drawing (see below).

[LNERGE]

Many thanks for the replies.

 

If I put a shunt signal before the yard points, as suggested, can I assume that these points will also have to be controlled from the signal box? Up until now I had thought of them as being operated on the ground by a shunter.

 

I’ve modified the drawing (see below).

Just for my benefit can you redraw the trap point in the siding to throw stuff away from the running line? The yard point needs to be controlled or left as a hand point with a new trap point and disc to stop stuff turning up unannounced on the running line.

[retbsignalman]

Hi!

Looking at your diagram, are the Up and Down Advance Starters really needed? I ask as any moves onto the single line in advance of the Up/Down starters could be covered by 'shunting into the advance section' (bell codes 5-2 and 2-5 - can't remember which way round they are, its been a long time since I worked Forres!), this can only be done when there is no train approaching from either side - but a shunt move could follow a train which has departed the station.

 

If you made the ground signal controlling the exit from the goods siding a yellow bar disc signal (white/black disk with a yellow bar), then once a loco was in the goods siding, it could then run up and down to the loading bank with no signalman intervention. Only when it needed to exit the goods siding and the points reversed would the signal be pulled.

 

I see a need for three disc signals beneath the Down Home, which read left to right, top to bottom would apply: Goods Siding, loop and finally the platform siding, likewise one disc beneath the Up Home, one for entry to the loop. In either direction, the loop access signal could be a shunt arm on a bracket (reducing the number of discs by one at each end..... 

 

Hope this helps!

 

Cheers G

[TheSignalEngineer]

The box end looks much better except for the trap in the platform siding mentioned by LNERGE, which needs to throw off to the left if something runs away.

 

At the other end, the Down Starter doesn't seem to serve any useful purpose in its present position, as there is no provision from getting back from it during a shunt and a train standing at it prevents anything else from moving at that end. 

[Kylestrome]

Just for my benefit can you redraw the trap point in the siding to throw stuff away from the running line? 

 

 

Oh, well spotted! I've built it correctly but drawn it wrong. 

[Kylestrome]

I see a need for three disc signals beneath the Down Home, which read left to right, top to bottom would apply: Goods Siding, loop and finally the platform siding, likewise one disc beneath the Up Home, one for entry to the loop. In either direction, the loop access signal could be a shunt arm on a bracket (reducing the number of discs by one at each end..... 

 

Hope this helps!

 

Cheers G

 

Funny you should say that, I've already built these signals but thought they might be overdoing it slightly. I'll use them after all.

[Kylestrome]

At the other end, the Down Starter doesn't seem to serve any useful purpose in its present position, as there is no provision from getting back from it during a shunt and a train standing at it prevents anything else from moving at that end. 

 

I'm afraid the layout is already at an advanced stage, and was a bit of an exercise in getting 'a quart into a pint pot'. It could have done with a bit of extra planning it would seem.

 

The platform face extends beyond the loop point, in the down direction, which means that putting the down starter before the point would not allow much space for a train to stop (loco + 2 coaches). The loop is intended to be used for shunting only, not as a passing loop. If only one train is allowed to be in this section, would I need any running signals at all?

[Grovenor]

 If only one train is allowed to be in this section, would I need any running signals at all?

 

No, if this station is not a block post, just a mid section siding you just need a ground frame released by the staff/token, everything would be proved normal in the block wires. No need then for lock bars either, just the actual locks. You do need all of the sidings to be trapped as already mentioned.

Regards

[LNERGE]

It can be a block post but not a token station. The Thrapston - Huntingdon line had an interesting method of working.

 

Birdbrook was a token station but couldn't pass trains..

 

http://www.disused-stations.org.uk/b/birdbrook/

 

Chaul End between Luton and Dunstable was the same.

[The Stationmaster]

It can be a block post but not a token station. The Thrapston - Huntingdon line had an interesting method of working.

 

Birdbrook was a token station but couldn't pass trains..

 

http://www.disused-stations.org.uk/b/birdbrook/

 

Chaul End between Luton and Dunstable was the same.

Pardon?  Of course it can be a token station if it is a block post (in fact I'm not sure how, on a single line, it could be a block post without being a token station as the authority to enter a single line block section is possession of the token, or whatever equivalent is in use, as well as the Section Signal being cleared).  Instances of block posts (and therefore by implication token station) without passing loops wasn't exactly unusual on the pre-Beeching railway - the important thing being that they were not allowed to accept trains in both directions at the same time - for obvious reasons.  

 

As the Block Regulations put it when referring to -

'Line Clear or Giving Permission For A Train To Approach'

at a token station which is not a crossing place, if the line is clear for at least quarter mile beyond the home signal and permission has not been given for a train to approach in the opposite direction'

 

ET Regulations 1960 and 1972 wording, the principle is unaltered in the 1990s version but the wording is much changed.

[LNERGE]

Pardon?  Of course it can be a token station if it is a block post (in fact I'm not sure how, on a single line, it could be a block post without being a token station as the authority to enter a single line block section is possession of the token, or whatever equivalent is in use, as well as the Section Signal being cleared).  Instances of block posts (and therefore by implication token station) without passing loops wasn't exactly unusual on the pre-Beeching railway - the important thing being that they were not allowed to accept trains in both directions at the same time - for obvious reasons.  

 

As the Block Regulations put it when referring to -

'Line Clear or Giving Permission For A Train To Approach'

at a token station which is not a crossing place, if the line is clear for at least quarter mile beyond the home signal and permission has not been given for a train to approach in the opposite direction'

 

ET Regulations 1960 and 1972 wording, the principle is unaltered in the 1990s version but the wording is much changed.

Sorry substitute 'It can be a block post but not a token station or a token station' in place of '.It can be a block post but not a token station'.  For example a train leaving Huntingdon for Thrapston. The driver need to see the staff and can go forward on a ticket. Once he has passed Buckden out of section can be sent and a second train can be allowed to leave Huntingdon, again on a ticket or with the staff. The second train cannot go beyond Buckden until the first train has passed beyond Grafam and so on and so forth.

 

Token stations were huntingdon No1, Kimbolton and Thrapston. Block posts were Buckden, Grafam and Raunds. Nothing could go the other way until the staff arrived on the last train. What i don't know is whether a fast train could overtake a slow by swapping staff and ticket at say Buckden?

[Kylestrome]

I had a feeling things would get complicated.  

 

I think the simplest thing for me to do would be to adopt Marc's 'one engine in steam' idea and do without signals altogether. This is only supposed to be a West Highland backwater, which is being kept open into the blue period mainly for freight.

 

Thanks again for the feedback.

[RailWest]

I think this is a good example of where the generic term 'token' causes confusion. There were certainly examples of 'intermediate block posts' on 'staff & ticket' lines (Staverton on the Ashburton Branch comes to mind), but with one exception [#] I'm not aware that such a situation was possible or existed on any line using electric train staff/tablet/token.

 

# There was at least one line (Berney Arms IIRC?) where the permissive form of Tyers No 5 ETT was used.

[meil]

I don't see the need for the Advance Down Starter.

 

Also I would swap the positions of the up AS with the Down H. In fact why have the AS. By having the Starter as the Section signal you could have a train in the station and accept another under the Warning acceptance (3-5-5) and put it in the siding. As you have it (with the AS as the section signal) you can't do that.

 

Its all very well shunting into the section by using asking for a token (5-2) but it can become a PITA for the signalman.

 

Also if you change the CP in the loop for small head shunts you increase the length of the loop quite a lot for train storage.

 

If you want to see a very similar situation look at Highley on the SVR: http://www.svrwiki.com/Highley_signal_box

[ForestPines]

Its all very well shunting into the section by using asking for a token (5-2) but it can become a PITA for the signalman.

This is particularly true if the line would have had one of the earlier "non-replaceable" types of tablet instrument, which did not allow the token to be returned to the same instrument it was withdrawn from - the token always had to travel through the section.

[retbsignalman]

Out of interest, what drawing programme did you use to create the diagram please?

Ta

G

[meil]

This is particularly true if the line would have had one of the earlier "non-replaceable" types of tablet instrument, which did not allow the token to be returned to the same instrument it was withdrawn from - the token always had to travel through the section.

In that case your only choice would be to block back outside the Home (3-3).

[Kylestrome]

Out of interest, what drawing programme did you use to create the diagram please?

Ta

G

 

I used my favourite and, alas, long lamented drawing program FreeHand MX. It could just as easily have been done it with Illustrator or any other 2d vector package, though.

[RailWest]

>>>Also I would swap the positions of the up AS with the Down H. In fact why have the AS. By having the Starter as the Section signal you could have a train in the station and accept another under the Warning acceptance (3-5-5) and put it in the siding. As you have it (with the AS as the section signal) you can't do that....

 

I don't understand that argument. Provided that subsequently you do not allow anything to foul the 'signal section' between the Starting and Advanced Starting signal, then I see no reason why you can't keep a train in rear of the Starting and then accept another from the opposite direction under Reg 5, assuming that it has been authorised for use at that location - tho' frankly the overlap beyond the Home towards the Starting seems short enough to make that a rather risky process. Alternatively, keep the first train in the platform, then reverse the facing points for the loop and - assuming that the loop is clear - accept under Reg 4.

[Kylestrome]

In view of the difficulties concerned with the convincing placement of signals I have decided that the layout will be operated on a strictly one engine basis.

 

I have re-drawn the signal box diagram in a more recent style, using Mallaig as reference, and without signals.

[RailWest]

If point 8 is going to be worked from what is now a ground-frame, rather than being a hand-point, then 9 could be worked from 8 as well - no need for separate levers.

[meil]

>>>Also I would swap the positions of the up AS with the Down H. In fact why have the AS. By having the Starter as the Section signal you could have a train in the station and accept another under the Warning acceptance (3-5-5) and put it in the siding. As you have it (with the AS as the section signal) you can't do that....

 

I don't understand that argument. Provided that subsequently you do not allow anything to foul the 'signal section' between the Starting and Advanced Starting signal, then I see no reason why you can't keep a train in rear of the Starting and then accept another from the opposite direction under Reg 5, assuming that it has been authorised for use at that location - tho' frankly the overlap beyond the Home towards the Starting seems short enough to make that a rather risky process. Alternatively, keep the first train in the platform, then reverse the facing points for the loop and - assuming that the loop is clear - accept under Reg 4.

As drawn you have overlapping blocks (the AS is the section signal - pointless having it if it's not). So if you have accepted a down train under reg 4 you cannot accept an up train even under a warning acceptance because you have fouled your clearing point for the up train and you are not clear to the Home as required by reg 5.

 

If the AS is removed or repositioned to be in advance of the up Home then you can accept an up train to the Home (this does require a mod to the clearing point ie it is not 440 yds in advance of the AS but is at the AS) under the Warning acceptance.

 

Alternatively you accept both trains under a warning acceptance and hold the UP train at the Home to permit the Down train to enter the loop (strictly not a loop more a siding as there is no platform and hence this cannot be a passing post - like Highley).