Double track terminus shunt moves.

[RJS1977]

My club are considering building a new double track terminus next year (which can be bolted on to our main layout with operators passing trains between the two).

 

Some shunt moves (e.g. accessing the loco shed, or possibly ECS movements, depending on the plan chosen) will need to be made outside the confines of the terminus and encroach on the "main line" connecting the two layouts.

 

Is there any hard and fast rule about whether such moves should be made on the "Up" (i.e. departing line) or the "Down" (arrival) line?

 

[Peter Kazmierczak]

Do you have a plan?

[Grovenor]

Normally on the departing line, shunting out onto the arriving line needs extra signallingand/or blocking traffic. Only used if no alternative.

[Chimer]

I would have assumed (always a bad idea 🙂) that if the loco shed is accessed from the main line away from the station, locos would use the up to go on shed and the down on their way back, with trailing access to the shed from from one line or the other and an adjacent trailing crossover.  But maybe not so these days with rationalisation and  "cleverer" signalling?

[RJS1977]

Currently considering this idea, loosely inspired by Ramsgate Harbour.

 

 

As depicted in the plan, a loco coming from the top of the layout would cross on to the arrivals line then run on to the shed. 

 

The obvious solution would be to move the trailing crossover outside the facing one, but that would take it outside the confines of the two 4' baseboards, or would squash the station  up so small as to be unworkable.

[RJS1977]

Actually, perhaps the simplest solution would be to flip it through 180 degrees:

 

 

This has the added advantage of bringing the goods yard closer to the operator(s) to simplify uncoupling.

 

My only concern  with doing it this way round is that the next board is the "handover" board to the rest of the layout, so if the operator up the far end is slow in taking over a departing train, all movements on and off shed are blocked. (Or the other operator could see a light engine arrive on the "handover" board and think it's for them to take).

[Harlequin]

How long is the handover board? Can you extend some of the station onto it (because 8ft is pretty cramped)?

 

It would be more realistic to have a good distance of straight track in front of the loco shed.

 

The kickback goods shed might be annoying to shunt (or fun depending on your viewpoint). It might be better to have the goods shed in a more conventional position, like Ramsgate Harbour, and the Loco shed kicking back, possibly on the handover board.

 

[The Johnster]

12 hours ago, RJS1977 said:

 

Is there any hard and fast rule about whether such moves should be made on the "Up" (i.e. departing line) or the "Down" (arrival) line?

 

12 hours ago, Grovenor said:

Normally on the departing line, shunting out onto the arriving line needs extra signallingand/or blocking traffic. Only used if no alternative.

 

Long time since I worked on the railway (worked, who you tryna kid, Johnster), so I'm not up to speed with current or recent practice, but on a 'traditional' railway in the UK, shunting moves out of a station, terminus or through, are either carried out either in the direction of travel (up on the up line), and may run into the signal section in advance if it is clear; the reversal of the move is signalled by a ground signal controlling what is now a movement in the wrong direction (down on the up line), or against the direction of travel, on the 'wrong' road, (up on the down line).  In this case, of course, it is important the no traffic enters the signal section from in rear while the move is taking place, and the move will be protected by a main signal at danger.  There is a safety overlap to cater for SPADs &c, though, and the shunting move must not compromise that, so there will be a 'Limit Of Shunt' board, backlit at night, beyond which no vehicle of the shunt must not pass.  It is positioned to be read in the 'wrong' direction from the 'wrong' road.  The reverse part of the move (down on the down line), will be signalled by a ground/subsidiary signal or a main signal aspect, if there is one.  

 

The basic principle of all this is a part of absolute block signalling on double track lines, and is used in both semaphore section signalling and MAS signal section signalling.  In semaphore signalling terms, the moves are carried out within 'station limits', that is, the area between a signal box's outermost home signal and it's most advance starting signal, but the principle is the same for MAS.

 

 

[DCB]

On 18/12/2023 at 21:19, RJS1977 said:

Actually, perhaps the simplest solution would be to flip it through 180 degrees:

 

 

This has the added advantage of bringing the goods yard closer to the operator(s) to simplify uncoupling.

 

My only concern  with doing it this way round is that the next board is the "handover" board to the rest of the layout, so if the operator up the far end is slow in taking over a departing train, all movements on and off shed are blocked. (Or the other operator could see a light engine arrive on the "handover" board and think it's for them to take).

 

That is a very unusual trackplan. I cannot think of anything like it  with a great big 75ft turntable beyond the platforms.   Something from the 1850/75 era and never modernised with a 45 ft table maybe, but it's a huge waste of space. and horrendously dangerous for a full size railway.  I just would not bother with a huge turntable on site.   I would have the loco depot and carriage sidings off stage to get more movements

Generally shunting will be along the departure line.  That is because  when the arrival line is occupied by shunting  no other train can be  in the section  between the next station or signal box while the shunt is being carried out, that could be three miles nine minutes.  On the outgoing  as soon as the train is clear of station limits a shunt within station limits can be commenced 

Edited December 20, 2023 by DCB

[Jeremy Cumberland]

The reason the departure line tends to be preferred for shunting is entirely practical. The movement is within station limits and can be carried out without needing to disturb the adjacent signalman by blocking back into the section, and thereby causing any approaching train to be held at the preceding signal box (which might be a mile or two away).

 

The practicalities of model railways are different. From your description it sounds like each line on the handover board is primarily under the control of the operator at the receiving end. This being the case, you would be better to use the arrival road. There will be no risk of the operator at the other end thinking that the train is for him, nor will you be affected by his late picking up of a departing train. The only thing that may happen is that he will try to send you a train while you are shunting, but this can be alleviated by following prototypical practice and having a "blocking back" signal, some indication to the other operator not to try sending you a train.

[stivesnick]

Hi 

 

As others have noted, I would also get rid of the turntable. This would allow the platforms to move to the left and create a bit more space on the right side so the crossover is clear of the platform end.

 

Some further thoughts and questions:

• Many terminal stations had a third "releif track" whihc could be used for shunting whislt limiting the impact on the main running lines. It was also used when the engine shed or carriage sidings were away from the main station. 
• It would be worth knowing what era the layout is set in, as this would help establish what size the engine shed would need to be. 
• Many terminal stations would have had carriage sidings
• A few extra goods sidings that can be shunted without affecting the main arrivals and departures might be useful
• Many terminal stations would have had a dedicated parcels platform with parcels vans being shunting to and from the main passenger trains. 

Hope this is useful.

 

Nick 

 

[Harlequin]

I would keep the turntable but use a slightly smaller one if possible.

 

It's a space saver when set against the length of the pointwork, the length needed to bring the different approach angles together and the spur beyond the pointwork that would be required to replace the turntable.

 

Edited December 19, 2023 by Harlequin

[Mol_PMB]

If the station has an engine shed, it would generally suggest that locos need servicing between arriving on a train and departing on the next one. Therefore a different loco would take the train out, and the just-arrived loco would go on shed. In this scenario, run-round loops are not needed in the platforms, nor the extra length for the tracks to converge. 

But I suppose that will be influenced by the way that trains are run on the main layout - if a train sent to the branch comes back with a different loco on it, is that a problem?

 

If a large turntable is needed for the size of locos in use, is there a way to put it at the throat end (opposite the signal box maybe?)

[Colin_McLeod]

In the days of steam, the loco sheds for Belfast were about two miles away at Adelaide. There was a third road alongside the main line for light engine movements between station and shed.

[5BarVT]

6 hours ago, DCB said:

That is a very unusual trackplan. I cannot think of anything like it  with a great big 75ft turntable beyond the platforms.   Something from the 1850/75 era and never modernised with a 45 ft table maybe, but it's a huge waste of space. and horrendously dangerous for a full size railway.  I just would not bother with a huge turntable on site.   I would have the loco depot and carriage sidings off stage to get more movements

The turntable is a reflection of the original - Ramsgate Harbour.  The original had measures in place to make it safe for operation: on one road, there was a run off to buffers and the turntable was normally set to the other road so that there was a safe path a cross it.

So on the proposal for the model, I would have run offs to buffers on the two outer approaches (could be dummy points) and the turntable set to the centre road whenever running in to that platform.

Paul.

[tom s]

56 minutes ago, Harlequin said:

I would keep the turntable but use a slightly smaller one if possible.

 

It's a space saver when set against the length of the pointwork, the length needed to bring the different approach angles together and the spur beyond it that would be required.

 

Looks to be about 50 ft using the helpful chaps stood right on it as a reference.

[Michael Hodgson]

The double slip on the arrival line would be unusual.

The ability to arrive into and depart from all three platforms would be fairly unusual

A turntable positioned at the platform ends would also be most unusual in British practice.

It raises safety concerns if an arriving train were to overshoot, the table being aligned for another road at the time.

I don't know what locking implications that might have,

 

2 hours ago, Jeremy Cumberland said:

The reason the departure line tends to be preferred for shunting is entirely practical. The movement is within station limits and can be carried out without needing to disturb the adjacent signalman by blocking back into the section, and thereby causing any approaching train to be held at the preceding signal box (which might be a mile or two away).

 

 

I don't think creating work for the signalmen would have been the issue - they're paid to do a job of work, and they are there anyway.

I would think it would be more accurate to say the concern is safet - a train shunting on the line used for arrivals is an avoidable hazard.  A train or light engine movement needing to shunt on the departure line can be slotted in immediately when a train has gone and the line can be seen to be clear.  It's all under the control of the local signalman who has the best view of priorities if there are competing demands for a piece of track to be used.

 

If the line immediately to the right of the signalbox is a junction, that junction would presumably be controlled by that box.

 

If one were to shunt out onto the arrival line fouling the junction, one would have to cross the diamond crossing and block the other main line as well, whereas shunting out onto the departure line foul of the junction only interrupts traffic on one of your main lines.

[ikcdab]

6 minutes ago, Michael Hodgson said:

I would think it would be more accurate to say the concern is safet - a train shunting on the line used for arrivals is an avoidable hazard. 

You are right of course, but the regulations do provide for this. You can't give line clear to the box in rear until the line is clear to the clearing point. If the clearing point is to be fouled by a shunting move, then you need to block back first. But I do accept that accidents have happened in these circumstances, Knowle and Dorridge being one?

[melmoth]

12 minutes ago, Michael Hodgson said:

 

I don't think creating work for the signalmen would have been the issue - they're paid to do a job of work, and they are there anyway.

 

 

True, but I seem to recall reading something (probably by Adrian Vaughan) about how GWR signal boxes were graded for pay scales, and the grading depended to an extent on the number of individual actions a signalman had to undertake in the course of a normal shift. Therefore, in theory at least, creating more work for the signalman could lead to a claim for an increased rate of pay. Always assuming I have remembered and understood correctly.

[RobinofLoxley]

14 hours ago, RJS1977 said:

Currently considering this idea, loosely inspired by Ramsgate Harbour.

 

 

As depicted in the plan, a loco coming from the top of the layout would cross on to the arrivals line then run on to the shed. 

 

The obvious solution would be to move the trailing crossover outside the facing one, but that would take it outside the confines of the two 4' baseboards, or would squash the station  up so small as to be unworkable.

How much difference does it really make if a loco runs briefly onto the arrivals line compared to running up the departures line then crossing arrivals to reach the shed. Traffic on arrivals has to be stopped in both cases

[Peter Kazmierczak]

With the suggested plan, would you actually need to shunt the passenger stock as:

a) locos can run-round via the turntable

b) all platforms can be used for arrivals/departures

[Michael Hodgson]

2 hours ago, melmoth said:

 

True, but I seem to recall reading something (probably by Adrian Vaughan) about how GWR signal boxes were graded for pay scales, and the grading depended to an extent on the number of individual actions a signalman had to undertake in the course of a normal shift. Therefore, in theory at least, creating more work for the signalman could lead to a claim for an increased rate of pay. Always assuming I have remembered and understood correctly.

There was a very complex formula of scoring points for each box negotiated by the unions - a box had an equipment value (so many points for each level, bell etc) combined with a workload score (the number of bell signals sent, tralin/loco movements etc).  Boxes were grouped into bands for hourly rates so that a simple box was a low grade, and one could be promoted into a more complex/busier box in a higher grade - but had to work harder!

 

PS there was an NUR publication explaining how to calculate what your box should be graded as.

Edited December 19, 2023 by Michael Hodgson

[Dunalastair]

3 hours ago, 5BarVT said:

The turntable is a reflection of the original - Ramsgate Harbour.  The original had measures in place to make it safe for operation: on one road, there was a run off to buffers and the turntable was normally set to the other road so that there was a safe path a cross it.

So on the proposal for the model, I would have run offs to buffers on the two outer approaches (could be dummy points) and the turntable set to the centre road whenever running in to that platform.

 

Of course, it did not always go to plan at Ramsgate Harbour - though you cannot blame the turntable.

 

https://www.facebook.com/photo/?fbid=228309766435873&set=a.180969101169940&paipv=0&eav=AfYksOy_twITua0Bv05Uf4TLZtXXB4MGbk8D0vdNP-OETgA9lAiRd6KeSUbhs0Sm9Iw&_rdr

 

Sadly, there was also a gradient related accident on the NG Tunnel Railway which later occupied part of the site. 

 

https://theisleofthanetnews.com/2018/03/23/ramsgate-tunnels-has-big-plans-starting-with-the-new-home-front-museum-and-tunnel-teas-cafe/tunneltrain/

 

I remember reading about this when I modelled the other end of the Tunnel Railway.

 

[Dunalastair]

10 hours ago, DCB said:

 

That is a very unusual trackplan. I cannot think of anything like it  with a great big 75ft turntable beyond the platforms.   Something from the 1850/75 era and never modernised with a 45 ft table maybe, but it's a huge waste of space. and horrendously dangerous for a full size railway. 

 

Did Bembridge and Ventnor across the Solent not both have a similar arrangement, albeit with smaller turntables?

Edited December 19, 2023 by Dunalastair

[The Stationmaster]

19 hours ago, RJS1977 said:

Currently considering this idea, loosely inspired by Ramsgate Harbour.

 

 

As depicted in the plan, a loco coming from the top of the layout would cross on to the arrivals line then run on to the shed. 

 

The obvious solution would be to move the trailing crossover outside the facing one, but that would take it outside the confines of the two 4' baseboards, or would squash the station  up so small as to be unworkable.

The train ing crossover os in the wrong place and should be at extreme right of the track layout.  this is for several reasons, viz : -

1. It then allows access from all lines to the departure, which in tirmn,

2. Allows all shunts to be made via the departure line, which in turn reduces potential impacts on, and delays to, arriving trains, and

3. Simplifies and reduces the cost of signalling the layout.

 

6 hours ago, ikcdab said:

You are right of course, but the regulations do provide for this. You can't give line clear to the box in rear until the line is clear to the clearing point. If the clearing point is to be fouled by a shunting move, then you need to block back first. But I do accept that accidents have happened in these circumstances, Knowle and Dorridge being one?

Actually the Regulations don't exactly do that.  What they do is prevent another train being accepted, let alone approach, if a shunt is made on a Block Back in the wrong direction into/towards a block section.   But there is nothing, except the staff involved. in carrying out the movement, who will prevent that shunt running away in the wrong direction.  When the shunt is madea on the departure line any runaway would at least be in the right direction.   And runaways in the right direction are in many respects preferable to runaways in the wrong direction

 

6 hours ago, RobinofLoxley said:

How much difference does it really make if a loco runs briefly onto the arrivals line compared to running up the departures line then crossing arrivals to reach the shed. Traffic on arrivals has to be stopped in both cases

Not the same in Signallinmg Regulation terms and ata. busy terminus that simple difference can mean not only more wrk for a Sif gnalman (so he might get paid more) but also can lead to greater potential delays to arriving trains.

 

Another signalling feature to be borne in mind is the presence and position of the turntable.  it would be required to be set for the line on which a train is going to arrive - which means someone will have to be there to do that job.  In addition it is mre tythan likely - and was eventually required - that signals for arriving trains would have to be interlocked with the turntable (usually done vuia a bolt worked from the signal boX and applying to every ,ine on which a train could be signalled to arrive by means  of fixed signals.