Cotes Lane

[Tase]

Hi guys,

 

I would like to make a small DCC layout loosely based on the Ipswich depot. I would be grateful for advice on signal placement including whether I need/should have any GPL's. The layout is a contemporary one that will run all the TOC's from privatisation.

 

The total layout size will be 8ft by 2ft

 

I look forward to your comments, criticisms and assistance. Track plan attached.

 

Happy new year!

 

 

[kenw]

Hi Tase,

 

As it stands,

A 3 or 4 aspect colour light on each main line on approach to, protecting, the junction.

On the Up line signal a subsidiary PL (post mounted) for into the depot.

A 3 aspect colour light out of the depot, with a subsidiary PL for Up trains to back out onto the Up line

An Up direction GPL on Down line, opposite the Up line signal, to back trains into depot.

 

On the track layout;

 

Trap protection is required between sidings and the main line.

This could be provided by adding a headshunt which would also remove the need for any shunting moves within the depot to use the main line. The sub.PL on yard signal would also serve into the headshunt, with a GPL provided out of it.

 

While a facing direction mainline crossover giving access to the depot is more likely in contemporary practice than in the past, adding a trailing crossover would avoid Up trains having to back out wrong direction onto the Up line, they could then back out right direction on the Down before crossing over to depart on Up line. The Down Line (Up) GPS could also cover this move.

 

For Up direction trains to serve the yard (arriving or departing), some run-round facility in the yard, perhaps on the two sidings nearest main lines?

 

Hope this is of help,

 

Happy New Year

[Tase]

That's very helpful Kenw. Your comments have given me some food for thought. Looks like I'll be making a few changes!

 

Thanks again.

[St. Simon]

Hi,

 

I would add a headshunt onto the Depot, as shunt moves onto the main line wouldn't be specified when the project would be scoped, as it would have an adverse effect on the running of passenger trains, something that is very keenly avoided nowadays.

 

Simom

[Tase]

Cheers Simon. I'm just revising the track plan to incorporate a headshunt and adding signal placement. I'll post up the plan shortly for the experts to scrutinise again please.

 

Kind regards

[Tase]

Taking onboard the comments above I've revised the track plan and now placed the signals.

 

Couple of questions if I may;

 

Does this track plan now work?

 

Are the signals placed in the correct position?

 

Diagram key; Red square will be 3 aspect signals and if it has a blue circle in, will have a PL mounted

                      Blue square will be GPL's

 

 

 

Cheers

 

[kenw]

Taking onboard the comments above I've revised the track plan and now placed the signals.

 

Couple of questions if I may;

 

Does this track plan now work?

 

Are the signals placed in the correct position?

 

Diagram key; Red square will be 3 aspect signals and if it has a blue circle in, will have a PL mounted

                      Blue square will be GPL's

 

Coats Lane revised with signals.png

 

 

Cheers

 

Yes, that looks as though would work better, and signals seem ok.

 

Just a couple of comments, for a contemporary arrangement, two separate crossovers would be much more likely than a 'scissors' arrangement, and would avoid you needing the main lines so far apart. I'd suggest, as you look at the plan, putting the trailing crossover to the left of the yard point.

It'd probably give you a better length of run-round in yard if the crossover was facing the other way round.

[imt]

Taking onboard the comments above I've revised the track plan and now placed the signals.

 

Couple of questions if I may;

 

Does this track plan now work?

 

Are the signals placed in the correct position?

 

Diagram key; Red square will be 3 aspect signals and if it has a blue circle in, will have a PL mounted

                      Blue square will be GPL's

 

Coats Lane revised with signals.png

 

 

Cheers

With the big caveat that this is your railway so do it how YOU like....

 

Herewith my 2 pennyworth for what its worth.  I'm not an expert, but have picked up pointers from this discussion over the years.  The real experts (who may well shoot me down) are elsewhere at the moment and you might like some food for thought before they turn up.  I am assuming this is a TMD?  Mainly locos but some incoming fuel and stores trains?

 

The layout has three things that I would suggest altering.  Two have been pointed out already, 1) remove the scissors and have a trailing crossover only - facing crossovers of any kind on a main running line are unusual (dangerous?), and 2) change the direction of the release crossover on the loop to give a longer run round  - three maybe 4 wagons. The third is about the head shunt.

 

You have inserted a double slip (from space pressures I am sure) which would add a safety problem.  There really "ought" to be no way that anything can get onto the main line from that head shunt.  If you remove the scissors you may have room to replace the slip with two turnouts - a trailing crossover from the main down line and a point to the right into the yard - which will mean the head shunt can have full access to the yard but no connection to the main line.  The "run round" will then be a reception siding for incoming trains, and movements from the yard will only be by the crossover onto the down line.

 

As to signalling.  In real life the main running signals would be at least 200 yards from the crossover - and probably further - to provide a safety overlap.  Certainly no main line train would be stopped just before the yard crossover - far too dangerous.  So you don't need those signals - but you might like them for atmosphere etc. (once more its your railway).  There would be GPLS for the reverse crossover between the main line, and another for the reverse crossover into the yard. Exit from the yard is by main signal as its onto a main running  line and so you don't need a GPLS there (had it been there it would have been of the yellow variety).

 

The reception siding (the one above the down line with the release crossover) would have a running signal reading onto the main line only, under signaller control and interlocked with the main line signals, all other  movements would be by hand control of points and hand signals (radio) by yard staff.  Just before the release crossover on the reception road you might like to stick in a "STOP and await instructions" board.

 

For locos/trains to enter the yard from the UP line they would run past the crossover and set back onto the down line, then run back into the yard onto the reception road, where they would await the yard foreman's instructions.  To get into the yard they would run back onto the head shunt and then forward to the appointed road.  Goods arrivals would either have the loco in the right palce for shuntinmg if they come from the down line, or the loco can run round to the head shunt if the train has set back from the up line.

 

Hope that helps the thought processes.

[Wherry Lines]

As far as I know, there are no facing cross-overs (or a set of scissor cross-overs) around the Ipswich stabling point. 

 

The 'birds eye view' function on bing maps is quite a useful tool for looking at track formations

 

If the link works, this is Ipswich: http://binged.it/1K9VsOL

[Tase]

Thank you both very much. Certainly has given me much to think about!

 

IMT, you assumption is correct - mainly a TMD with a provision for fuel and stores train. Off to edit the track plan again lol.... 

[kenw]

The layout has three things that I would suggest altering.  Two have been pointed out already, 1) remove the scissors and have a trailing crossover only - facing crossovers of any kind on a main running line are unusual (dangerous?), and 2) change the direction of the release crossover on the loop to give a longer run round  - three maybe 4 wagons. The third is about the head shunt.

 

You have inserted a double slip (from space pressures I am sure) which would add a safety problem.  There really "ought" to be no way that anything can get onto the main line from that head shunt.  If you remove the scissors you may have room to replace the slip with two turnouts - a trailing crossover from the main down line and a point to the right into the yard - which will mean the head shunt can have full access to the yard but no connection to the main line.  The "run round" will then be a reception siding for incoming trains, and movements from the yard will only be by the crossover onto the down line.

 

As to signalling.  In real life the main running signals would be at least 200 yards from the crossover - and probably further - to provide a safety overlap.  Certainly no main line train would be stopped just before the yard crossover - far too dangerous.  So you don't need those signals - but you might like them for atmosphere etc. (once more its your railway).  There would be GPLS for the reverse crossover between the main line, and another for the reverse crossover into the yard. Exit from the yard is by main signal as its onto a main running  line and so you don't need a GPLS there (had it been there it would have been of the yellow variety).

 

The reception siding (the one above the down line with the release crossover) would have a running signal reading onto the main line only, under signaller control and interlocked with the main line signals, all other  movements would be by hand control of points and hand signals (radio) by yard staff.  Just before the release crossover on the reception road you might like to stick in a "STOP and await instructions" board.

 

For locos/trains to enter the yard from the UP line they would run past the crossover and set back onto the down line, then run back into the yard onto the reception road, where they would await the yard foreman's instructions.  To get into the yard they would run back onto the head shunt and then forward to the appointed road.  Goods arrivals would either have the loco in the right palce for shuntinmg if they come from the down line, or the loco can run round to the head shunt if the train has set back from the up line.

 

Hope that helps the thought processes.

 

Sorry but, as the layout is said to be contemporary then facing main line crossovers are commonly used, avoidance of such was largely in traditional, and particularly, mechanical practice. Two crossovers would be used rather than a scissors arrangement.

 

Don't see what you're getting at with the double slip, as it operates correctly as shown. It does not give direct access from the headshunt to the main line. From the headshunt access is to either the reception siding or the rest of the yard and from the reception siding or yard sidings it correctly gives access to either the Down Main, or correctly providing trap protection into the headshunt.

The two seperate crossovers you suggest do the same and would be more usual in contemporary practice but not so much in a yard or where constrained for space. Access from the headshunt to main line wouldn't be a problem either, so long as it's not direct without trap protection.

 

On the signalling, the Down Main signal could be further back for overlap purposes, allowing for space constraints, why I'd not mentioned it. The Up Main signal would be ok as it is.

The exit signal from the yard is correct in being shown as a colour light (to the Down Main) with a post mounted Subsidiary PL giving access to the headshunt. The GPL shown alongside the headshunt reads out of the headshunt into the yard and is required to protect the trailing end of the slip (or crossover) giving access to the main line line as this would be power operated in tandem with the main line point (to provide the trap protection). The reception siding, being part of the yard, doesn't need a seperite exit signal, though could have one, and if so it would need a Sub.PL or you couldn't access the headshunt from that siding.

 

For locos / trains entering the depot they'd set back through the crossover? Sorry, but NO WAY in modern practice. They'd need to stop and the driver change ends  - twice - for this movement. With the time taken to walk end to end, plus modern stocks tendency for a two minute time-lock on the AWS to release the brake each time the desks re-energised, such a move would take around ten minutes, blocking the main lines while it did so! Hence the possible preference for having that facing crossover

 

Hope this helps clarify things

 

Ken (52A)

[kenw]

Hi Tase,

Sorry, but not knowing the area and from your original discription and the 'wagon sidings' tag I hadn't realised it's a TMD rather than some sort of freight depot. As such, there's scope for some simplification.

 

On the original plan with just a facing crossover, it looked as though you intended freight trains arriving onto depot in the Up direction.

As a TMD, if you assume to have your fuel / stores train arrive / depart in the Down direction, there's then no need for the run-round within the yard, saving the need to use two of your sidings for that purpose, as well as a crossover.

(Though in modern practice fuel / stores would arrive by road, though if you want to retain rail deliveries, it's your layout)

 

As a TMD, assuming it's 'intended' to serve a local station, then depending on the direction of it, one of the main to main crossovers could be dispensed with....

If the stations to the right as viewed on the plan you could dispense with the trailing crossover, trains arriving onto depot in Up direction through the facing crossover (avoiding that double reversal and changing ends!) and departing depot directly onto Down line.

If the stations to the left, then the facing crossover isn't needed, arriving or departing trains would need to stop on Down line and reverse direction (but just once!) either into depot, or though the trailing crossover to depart on the Up.

 

My previous comments on track layout in general and the signaling still apply, You'd simply dispense with any signals for any points you take out.

 

Movements within the depot would be under control of the Depot Supervisor, include giving the signaler permission to signal movements into the depot having ensured the appropriate road's set (probably by hand points)

 

Ken (52A, sometimes at 52B)

[imt]

Sorry but, as the layout is said to be contemporary then facing main line crossovers are commonly used, avoidance of such was largely in traditional, and particularly, mechanical practice. Two crossovers would be used rather than a scissors arrangement.

 

Don't see what you're getting at with the double slip, as it operates correctly as shown. It does not give direct access from the headshunt to the main line. From the headshunt access is to either the reception siding or the rest of the yard and from the reception siding or yard sidings it correctly gives access to either the Down Main, or correctly providing trap protection into the headshunt.

The two seperate crossovers you suggest do the same and would be more usual in contemporary practice but not so much in a yard or where constrained for space. Access from the headshunt to main line wouldn't be a problem either, so long as it's not direct without trap protection.

 

On the signalling, the Down Main signal could be further back for overlap purposes, allowing for space constraints, why I'd not mentioned it. The Up Main signal would be ok as it is.

The exit signal from the yard is correct in being shown as a colour light (to the Down Main) with a post mounted Subsidiary PL giving access to the headshunt. The GPL shown alongside the headshunt reads out of the headshunt into the yard and is required to protect the trailing end of the slip (or crossover) giving access to the main line line as this would be power operated in tandem with the main line point (to provide the trap protection). The reception siding, being part of the yard, doesn't need a seperite exit signal, though could have one, and if so it would need a Sub.PL or you couldn't access the headshunt from that siding.

 

For locos / trains entering the depot they'd set back through the crossover? Sorry, but NO WAY in modern practice. They'd need to stop and the driver change ends  - twice - for this movement. With the time taken to walk end to end, plus modern stocks tendency for a two minute time-lock on the AWS to release the brake each time the desks re-energised, such a move would take around ten minutes, blocking the main lines while it did so! Hence the possible preference for having that facing crossover

 

Hope this helps clarify things

 

Ken (52A)

Sorry I have been playing about with putting a new layout diagram in, and failing - badly.  It is probably too small to read and I hadn't intended to post it.

 

Kenw - I have read both your posts.  Thank you for the detailed reasoning - it helps the ignorant (like me) understand things better.  However I must say the thought of it taking about 5 mins to reverse a double ended diesel loco is quite horrifying.  It is obviously just as well that the amateurs like me don't try operating timetables in real time.  To run round some stock from a newly arrived train would obviously take about 20 -25 minutes in reality - including brake tests etc..  Good job shunters are single ended? No wonder DMUs are so popular with operators.  I take your point about the slip.  I like slips - they save space but like in the 1:1 are expensive and maintenance heavy.  In Hattons terms 2 * £9 as opposed to £28 to buy!

 

Tase - sorry if I caused confusion and for any misleading.  Given Kenw's information I would suggest you need double entry to your yard - see the diagram if you can read it.  The entry from the UP main line is over a diamond crossing over the down line, the entry from the down line is at the left by a facing crossover.  This at least means that the entry to the yard is forward in both directions.  I don't think you have room for double crossovers  from the Up line.  Presumably you would have to block the running lines for 5 minutes when sending a loco out - since it would have to reverse direction.There would need to be signals at A and B on the main line I guess, and one at each exit from the yard.