Alternative main line terminus in OO

[jamespetts]

Thank you for your reply. The main attraction of the ADM turntable is that the people who make it provide a bespoke option: 309mm is still far too large - I need a turntable of circa 280mm.

 

In relation to the orientation of the locomotives, can you elaborate a little on the nature of this problem so that I can ask about it on the Traincontroller forum?

 

Thank you again.

[john dew]

Thank you for your reply. The main attraction of the ADM turntable is that the people who make it provide a bespoke option: 309mm is still far too large - I need a turntable of circa 280mm.

 

In relation to the orientation of the locomotives, can you elaborate a little on the nature of this problem so that I can ask about it on the Traincontroller forum?

 

Thank you again.

 

280mm  .....11" sounds quite tight. I am not familiar with SR 4-6-0s but a GWR Castle measures a smidgeon under 11" overall. 10" from front pony wheel to rear tender wheel.....less than 1" stopping tolerance.  You may have to reduce or eliminate the braking ramp. The abrupt stop may be unprototypical but may provide more consistency. If the TT is to be custom made I wonder if additional indicators could be wired in a short distance from each end

 

As you know TC needs not only the identity of a loco when it is assigned to a block but also its orientation ie direction in which it is pointing (not to be confused with direction of travel). When a loco on a TT bridge turns thru 180o the orientation is changed. If TC doesnt pick this up from the turntable decoder the loco will move off the bridge in the opposite direction to that intended. This was the issue that plagued me for four years with my Heljan TT and ultimately caused me to replace it with a supported TT.

 

In fairness I had 11 entry/exit roads which allowing for house/non house orientation created 20 different addresses. The way your TTs are set up each will only have two addresses which will simplify matters considerably.......you may want to read the section in the manual about linking a basic analog turntable to TC. I have a very elderly non DCC Fleischmann TT set up like this in my storage yard and it works without any orientation issues.

 

Best wishes

 

John 

[jamespetts]

280mm is 70ft in 4mm/ft scale - and 70ft was a fairly large turntable for the period: the GWR never had a turntable larger than 65ft, for example, and many shorter turntables existed.

 

Thank you for your clarification in relation to the orientation issue - I have asked the question on the Traincontroller forum. It is useful to know that the basic analogue motorising works well with Traincontroller - can I ask how this is controlled so far as hardware is concerned?

[jamespetts]

I have made some amendments to the design of the engine sheds following some feedback from a member of the Model Railway Club this evening, and have also amended the design of the fiddle yards to prevent deadlocks if all of the post-reversing loop part of the upper fiddle yards are full and a train needs to be released from the pre-reversing loop part of the fiddle yards. One of the fiddle yard roads has been made shorter, but another has been made longer in consequence of this.

 

There appears as if there might be room to add a fourth road on the LSWR engine shed, but I have not had time to test this this evening.

 

The revised plan is here:

 

[john dew]

280mm is 70ft in 4mm/ft scale - and 70ft was a fairly large turntable for the period: the GWR never had a turntable larger than 65ft, for example, and many shorter turntables existed.

 

Thank you for your clarification in relation to the orientation issue - I have asked the question on the Traincontroller forum. It is useful to know that the basic analogue motorising works well with Traincontroller - can I ask how this is controlled so far as hardware is concerned?

I guess there are many scale discrepancies when we model! My point was that consistently stopping a 10” wheelbase loco on an 11” bridge can be difficult.

 

Operating an analogue TT with TC is described in more detail in either the manual or the help section. I use a stand alone Peco solenoid point motor as a relay ........this turns the TT on and off . A reed and magnet ( on both ends of the bridge ) act as an indicator enabling TC to activate the point motor. Its a bit Heath Robinson.....you could probably set up a more sophisticated indicator! I would only use it on an indexing TT with very limited exits.....but given that caveat...it works

[jamespetts]

Thank you for that - I will have to consider the issue of accurate stopping. I do plan to have all locomotives with back EMF decoders to enable accurate stopping, so hopefully that will not be too much of a difficulty when they are profiled properly.

 

---

 

Herewith a further revised plan following some additional feedback from a Model Railway Club member:

 

[jamespetts]

Progress on the interior fitting out of my shed has been delayed by my decorator being unwell, and I have mostly been concentrating on the N gauge layout, but I thought that it might be worthwhile giving some reconsideration to the arrangement of the fiddle yard. The existing design is based on a split level reversing loop design. This was done in order to allow trains to be reversed in the fiddle yards simply without need to use a turntable and without the need for any shunting in the fiddle yards.

 

However, following testing with Traincontroller on my small N gauge automation testing layout, it seems that it is not too difficult to get fairly accurate stopping positions and shunting operations entirely automatically. Further, it seems that turntables in fiddle yards are actually a more common feature than I had anticipated, being used in a number of Cyril Freezer layout plans, as well as on at least one very interesting exhibition layout, Liverpool Lime Street.

 

With that in mind, I thought that it might be worthwhile attempting to redesign this track plan to remove the split levels and reversing loops and use automated shunting and a turntable instead.

 

Below is a comparison of the two versions: first of all, a slightly updated version of the split level design with a straighter baseboard edge at the top (to allow the N gauge layout that is to be below it to have a little more width at the far end of the shed to assist in adding scenic features such as a station car park) and also a larger turntable for the LSWR engine shed, as I realise that the turntable specified is 70ft in HO scale, not OO scale: a 90ft turntable in HO scale would be a 76ft turntable in OO scale, so this is closer to the desired size. The LBSCR turntable I have left in place, as a 70ft turntable in HO scale is a 61ft turntable in OO scale, which is probably suitable for the lesser size of locomotives likely to be using this line.

 

Here is the slightly updated split level version:

 

 

And here is the new flat version:

 

 

From what I can work out so far, there are a complex set of advantages and disadvantages of each design.

 

Advantages of the new flat design

 

• No reversing loop is required, removing the narrow pinch point in the shed and giving free access to the window.
• The baseboard construction can be simpler and cheaper as no split levels are required.
• There are no gradients, so there is no possible issue with model steam locomotives being unable to pull 12 carriages uphill (even at 1.1%) without magnetic adhesion.
• There is no possible need for magnetic adhesion, so permanent magnet uncouplers can be used in place of electromagnet uncouplers.
• Locomotives can be (indeed, in many cases, have to be) changed in the fiddle yard, giving more realism and variety of stock on the layout (so that, e.g., an express train departing with one locomotive returns later with a different locomotive, not the same locomotive).
• There are more longer fiddle yards, allowing more longer trains to be fitted into the fiddle yards.
• This design allows the headshunt/relief line to be on the other side of the main lines than the split level design, simplifying the layout in the scenic section somewhat.
• This design allows all curves to be no less than 600mm radius, whereas the split level design has one curve of 580mm radius (albeit only on the relief line/headshunt).

Advantages of the original split level design

 

• There are far fewer possibilities for conflicting movements in the fiddle yard and the two fiddle yards are entirely independent of one another.
• No extra (and fully indexed) turntable is needed, which reduces a source of additional expense and possible unreliability.
• There is no problem, as there is with the current version of the flat design (and I cannot at present find a solution to this) of there being not enough locomotive sidings to enable easy kickback working for the locomotives in the fiddle yards especially for the LSWR line trains (orange sidings) - any suggestions as to how this might be solved in the flat version would be welcome.
• It might be easier to reach rolling stock at the back of the fiddle yard because this will be raised compared to the front of the fiddle yard (but I am not sure how this will work out in practice).
• This design allows for slightly more fiddle yard roads overall, albeit the extra ones compared to the flat design are short and some of them are single-ended and require shunting (there are more full length fiddle yard roads in the flat design).
• There is a longer run for the trains on the LSWR line in the scenic section.

(The disadvantages of each, of course, are simply the corollary of the advantages of the other).

 

I should be very grateful for any feedback, especially from anyone with experience of operating large fiddle yards as to which of the two designs is more likely to be workable in practice. I should also be grateful for anyone who has an idea of how much that various model steam locomotives in OO gauge can haul up a 1.1% gradient.

Edited October 28, 2018 by jamespetts

[Bulleidnutter]

If you're intention in mid 30s Southern era. The modernisation that the Southern were undertaking would have seen a combined MPD rather than 2 completely seperate MPDs, 2 sets of facilities as this would have been an extra cost and maintenance worry. More connections between either side of the station would have been added as the electrification along the Brighton was completed in 1929. So you could have one side electrified and one side non electrified.

[jamespetts]

If you're intention in mid 30s Southern era. The modernisation that the Southern were undertaking would have seen a combined MPD rather than 2 completely seperate MPDs, 2 sets of facilities as this would have been an extra cost and maintenance worry. More connections between either side of the station would have been added as the electrification along the Brighton was completed in 1929. So you could have one side electrified and one side non electrified.

 

The reason that I have the engine sheds separated is that I wish to be able to backdate the layout to the pre-grouping era in time, if and when I manage to acquire sufficient suitable rolling stock.

 

The Brighton electrification was completed in 1933, and I believe that the Western coastway was not electrified until circa 1937, so this would have been steam only in 1935. One can readily imagine that the Southern might well have delayed modernisation of the engine sheds (and signalling) until such time as electrification reached this part of the network.

[john dew]

Hi James

 

I suspect you know which version I prefer!

 

A layout with three turntables all controlled by RR&Co.....whats not to like?

 

I am sure you will do a better job than I but I found operating a lower level storage yard was not satisfactory.  All in all I think the advantages of the new one level layout outweigh the advantages of the original. I operate a simplified version of your new proposal and it works well for me.

 

Should you go for the new version I do hope there will be sufficient space for a full sized turntable in the storage yard.

 

Best wishes

 

John 

[jamespetts]

Thank you for your thoughts. Can I ask you to clarify what you mean here by a "lower level storage yard" - do you mean one entirely covered at the top? That is not what the split level design entails here, although the lower level reversing loop is covered by the upper level. May I ask what difficulties that you had with your lower level storage yard?

 

One thing that concerns me with the revised version is the prospect of problems with multiple conflicting movements. May I ask how you manage to overcome that with your own layout?

 

It would be very interesting to see a diagram of your fiddle yards if you have one to hand.

[john dew]

Thank you for your thoughts. Can I ask you to clarify what you mean here by a "lower level storage yard" - do you mean one entirely covered at the top? That is not what the split level design entails here, although the lower level reversing loop is covered by the upper level. May I ask what difficulties that you had with your lower level storage yard?

 

One thing that concerns me with the revised version is the prospect of problems with multiple conflicting movements. May I ask how you manage to overcome that with your own layout?

 

It would be very interesting to see a diagram of your fiddle yards if you have one to hand.

 

Hi James

 

I dislike storage yards which are even partially covered where access becomes difficult. I spend a lot of time maintaining my locos and rolling stock but locos will occasionally not start or rolling stock uncouples.......reaching over other stock to reach the offending train it is easy to brush against another train causing a derailment or uncoupling.

 

The block and route reservation system in Train Controller prevents many conflicts. I have resistive wheel sets on most of my rolling stocks so that routes cannot be released until the entire train has passed rather than just the loco. When I am still concerned about a conflict I lock the entry or exit of a block........the protected train releases the entry/exit by either an action marker or a schedule block action. I link some of these actions to signal objects on the switchboard to more clearly indicate that a block is temporarily locked 

 

Here is a screen shot of my storage yard switch board

 

 

 

 

I have tried and failed to save an enlarged version. Hopefully, if you wish, you can zoom in on your computor.

 

It was built 10 years ago and a number of design faults have been revealed over time. I do admire (and envy) the research based approach you have adopted.

 

The track plan is oval and I originally envisaged trains just doing complete circuits in a fixed direction

 

I then added suburban trains hauled by tank engines doing out and back routines with loco exchanges taking place automatically at both storage and the bay platforms........I think you have seen videos of this...it works well with minimal supervision.

 

Goods trains still run fixed circuits.....its too complicated changing brake vans as well as locos although I am tempted to top and tail.

 

The locos for Express Passenger, Milk and Parcel Trains currently stay in the same orientation ie a train leaves the Up storage and arrives at the Down Storage. The loco uncouples and shuffles either to a spur or direct to the up storage to couple with the recently arrived down train........not entirely realistic but at least the trains travel in both directions!   

 

However, when passenger trains arrive at D5, the bottom-most storage siding, the loco uncouples, a pilot pulls the train clear to the carriage siding allowing the released loco to move to the storage turntable, the pilot returns the carriages to D5 and the turned loco re-couples with the train for the return journey to Granby...........there are variations with different locos ready for departure.

 

I imagine this is the sort of routine you would be adopting if you go with version 2? 

 

Hope this is helpful rather than confusing

 

Regards

 

John

[jamespetts]

Thank you for your thoughts: that is most helpful. There are a number of issues here, so I will break this into sections.

 

Covered storage yards

 

None of the storage roads themselves in my split level design would actually be covered; only the lower reversing loops and some crossover points at the entrances at both ends. This would seem to be less liable to difficulties with derailments than what you describe, although it is difficult to be sure how much of an issue that this would be without extensive testing, by which time it would be too late, I fear.

 

Your storage yards

 

I have been able to get the full resolution version: thank you for uploading that: that is most interesting. I have seen your suburban working videos showing, I think, kickback working, but I am not quite sure that I follow how your work your express passenger, milk and parcels trains.

 

Let me see if I can understand the sequence: the milk/parcels train departs from section 688 on the up relief at E or the up main at F passing through the crossover. It does whatever it is supposed to do in the station area and arrives back in the storage yard at C. It then crosses over to the down line using the crossover and arrives at 674. It is from here that I am a little unclear - does the locomotive go to 675? If so, where does it go from there and what happens with the down freights from 687 and 672? Does it go through 685 to get to the turntable? What if the Phewlli train is in? Presumably, it then goes to the turntable - but where does it go after that? Does the same or a different engine re-attach to the parcels/milk train at 674? If so, presumably it goes back through D and arrives at G, crossing over back to 688 - but what then happens to the locomotive?

 

I think that I understand the routine for the Phwelli trains at D5 (it is interesting that a fiddle yard only locomotive ends up being needed for this - quite a unique arrangement!), which is quite an interesting way of doing things, but I notice that you only do this for one rake of carriages at a time as it requires in effect two whole sidings for one train, which is potentially problematic for a layout that is somewhat limited in space and whose owner rather likes to maximise fiddle yard usage and thus train variety.

 

The split level and flat versions of my designs

 

It might be helpful to show the split level design split into its two levels, first of all the lower ((ex-)LBSCR) level:

 

 

and then the upper ((ex-)LSWR) level:

 

It is easier to see how this design is intended to work when the levels are split.

 

In the split level design, in the upper fiddle yard, most trains would arrive on the innermost green track to the left (I am afraid that mine are not labelled as yours) and either go into one of the upper orange sidings above the green line, or continue along the green line around the loop into one of the lower orange sidings. There it would remain until the time for its departure came, and it would then leave on the middle green line back to the scenic area.

 

The push-pull train with the O2 and the gate stock would arrive on the inner green and cross over before the reversing loop begins to the other side of the reversing loop and go into one of the orange sidings inside the reversing loop. When its time came to depart, it would then depart as normal.

 

Some short trains (e.g. locomotive coal for the engine sheds) would traverse the reversing loop so that they are facing back out towards the scenic section, then stop and reverse on the central green line into one of the orange sidings inside the reversing loop.

 

Similar principles but with minor differences would apply to the lower fiddle yards. These would be less busy as the line that these represent would be a more minor line.

 

One of the main advantages of this is that there would be very few conflicting movements. A train could arrive in the upper fiddle yard as another one is leaving. One train could be queued in the loop waiting for a road while another comes in and waits behind it, and at the same time a third leaves. All this can be happening while the same degree of activity is occurring on the lower fiddle yards.

 

The issue with conflicting movements is not so much that I fear that the trains will collide, as I know that TrainController is good at preventing that, but rather that the conflicts will severely limit the efficiency of the fiddle yards and their capacity to process trains quickly. This is why I am very interested in the details of your operations.

 

A brief glance at the 1938 timetable suggests that the layout will need to be capable of at handling at least 7 down trains (and by inference also 7 up trains) on the LSWR lines towards London alone in an hour, making for 14 train movements an hour or one every four and a quarter minutes, on average. This would not include the push/pull branch trains, trains working from the LBSCR lines, reversing and going out onto the LSWR lines, trains heading further west along the South coast to Poole/Weymouth, nor parcels/mail trains, and the figure of four and a quarter minutes is only an average: there will be times when the actual headway is much less than that in the space of any given few minutes. The fiddle yards (especially those on the LSWR lines, coloured orange and dark green on the plans) will thus need to be able to receive or dispatch a train up to every 1-2 minutes at peak, and perhaps every 4 minutes or so over a sustained period. The split level design could probably handle this - but I have doubts about the flat design.

 

The way that I had envisaged the flat design working (again, using the LSWR/orange lines as an example) is this: a train would arrive on the middle green line and cross into one of the orange lines, depending on its length. There would be permanent magnet uncoupler at the end of each road and the locomotive would uncouple from its carriages automatically by that expedient (I plan to use Kadee couplers, which provisional tests show to be very good).

 

At the first opportunity (i.e. when the relevant tracks are clear) a locomotive would come from one of the blue sidings and couple to the front of the train. When the train leaves again, the locomotive that hauled it in would, if a tender engine, go to be turned, and then return to a blue siding, and, if a tank engine, would go straight to the blue siding.

 

The push/pull branch train would repose at the top of the kinked green track near the upper blue sidings, having been dispatched along the relief line in red on the diagram. (Alternatively, it might use the same main line and repose in one of the shorter orange sidings).

 

However, I anticipate that this pattern would cause two problems: firstly, there would be congestion on the pointwork at the entrance/exit to the storage yards, as trains entering, trains leaving, light engines going for turning and light engines coming back from being turned would all need to use many of the same crossovers at the bottom left. From what I can work out so far, the most contention would arise on the green road leading to the turntable, the ladder of points leading to the large number of orange sidings (which would have to accommodate all arriving and all departing trains as well as all arriving and all departing light engines - tank engines could use the upper part and avoid the lower crossovers entirely, but tender engines would have to conflict with all incoming and outgoing train movements at the scissors crossover for each inbound and outbound movement) and the scissors crossover and double slip at the bottom left of that crossover.

 

Secondly, there is not room for enough of the blue sidings: I count a total of 8 (possibly 9) usable slots for the LSWR lines (leaving only a further 2 usable only by the LBSCR lines) if the longer middle siding is to be used as a headshunt and assuming that a further locomotive can fit in front of this, and this may not be quite enough slots for all the trains with all their various types of locomotives (including at minimum types LN, N15, D15, T9, 700, M7, and N, and, on the LBSCR lines, types E4, H2, N, possibly V, and that is without additional types that can possibly be built from kits in the future).

 

Compared to these difficulties, the possible difficulties of the relatively limited covered sections may well be minor.

 

The idea for switching to a flat design came, as I mentioned above, from the design for the N gauge layout that I am planning, which is somewhat more advanced in its planning, and looks like this:

 

 

This design has plenty of space for lots of locomotive sidings (being set in 1989, no turning is needed as all locomotives are diesel) on account of being in 1:!48 rather than 1:76 scale, and fewer potential conflicts as a substantial proportion of trains are DMUs or HSTs which need no internal light engine movements. I tried to translate the working ideas of the above N gauge fiddle yard back to this planned OO gauge layout, but I do not think that it has been entirely successful so far owing to the limited space for locomotive sidings and the potential for a higher proportion of conflicting movements.

 

However, I have not yet fully analysed the requirements - more locomotive storage space could conceivably be provided - but at the cost of train storage space. I am not sure whether conflicting movements might be limited enough to avoid the storage yard not having enough capacity to keep up with the timetable. Quite how to analyse this I do not know - any insight would be appreciated.

 

Miscellaneous

 

You refer to the time taken to plan the layout: this is, I must confess, largely a side effect of how long that it has taken the shed in which I plan to build my model railways to be completed, which has given me plenty of time to revise and improve my plans. If the shed had been completed much earlier, I suspect that an earlier version of my plans would have been put into production.

 

In any event, thank you very much for your insights: that is most helpful.

[jamespetts]

I have spent some time refining the flat version of the fiddle yards to see if I can eliminate some of the difficulties with conflicting movements described in my previous post. I have produced two versions of the improved design: one with and one without a second fiddle yard turntable.

 

Here is the version without the extra turntable:

 

 

and here is the version with the extra turntable:

 

 

In both versions, I have recoloured some of the lines for added clarity: the dark green are the fiddle yard access routes for the LSWR lines; the mid green are the fiddle yard access routes for the LBSCR lines; and the light green are shared access routes. The orange are the storage roads for the LSWR lines, the yellow the storage roads for the LBSCR lines and the brown storage roads that can be used by either. As before, blue represents locomotive sidings.

 

In both versions, I have added a headshunt at the top of the upper (LSWR) ladder and marked out the end of the siding from the relief line as a storage road, as it is intended to house the O2 and push/pull set.

 

In the version without the extra turntable, there are now 12 locomotive storage roads for trains on the LSWR lines, 2 mixed use locomotive sidings and 8 locomotive sidings for the LBSCR lines, making 22 in total.

 

In the version with the extra turntable, there are 15 locomotive storage roads for trains on the LSWR lines, 1 mixed use locomotive siding, and 9 locomotive sidings for the LBSCR lines, making 25 in total. Additionally, in the version with the extra turntable, what has to be a through line in the version without the extra turntable (shown in light green between the brown and yellow lines) can be a mixed use LSWR/LBSCR storage road, shown in brown on this version, increasing by 1 the number of storage roads available. The extra storage road has a usable length of ~2,500mm.

 

The first version should solve the problem with the lack of locomotive sidings, but there are still a high number of conflicting movements, as in the original version, as all locomotives must use the one turntable to turn, creating a large number of movements over the dark green crossovers at the left. The version with the second turntable reduces the number of conflicting movements by allowing locomotives to access the turntable using the headshunt at the top, avoiding the crossovers, although there will still be conflict with any train higher up the ladder. The version with the extra turntable also simplifies the crossovers slightly by eliminating two double slips on the exits of the scissors crossing.

 

The flat version still does not have the property that the split level design has, however, of being able to queue trains in the reversing loop, so trains will not be able to move fully into the fiddle yard from the scenic section if there are any conflicting movements at all in the fiddle yard.

 

One possible issue with the flat design is that the fiddle yard baseboards are quite wide all the way along (1.03m), and reaching to the back is likely to be difficult. In the split level design, this might be less of a problem on account of the back being raised somewhat, although I am not sure quite how significant that this would be.

 

I should be grateful for any feedback on these modified designs and in particular the operational efficiency of these compared to the split level design.

[john dew]

Hi James

 

I now have a better understanding of both both flat (2 versions) and split. I think some of my concerns about the split level have been alleviated.

 

Also I now understand your definition of conflicts....I call them choke points

 

I think conflicts are likely to arise on the Up (to storage) LSWR line....the inner line is likely to be in frequent use by locos using it as a head shunt to access the TT. Most Up LSWR trains will therefore be using the centre line.

How many blocks and of what length do you envisage for the centre line between the last station turnout and the storage diamond xing?. Technically blocks should be at least as long as the longest train but I think you may want to fudge that. If the sector only had two blocks a LSWR train could not leave the station until the preceding train had fully entered its allocated storage siding......is this ok?

 

It might be worth mocking up a TC switchboard using the station layout (which seems to be settled) and just a few storage sidings as a start.

 

I will attempt to explain/defend Granby's storage yards separately!

 

Regards

 

John

Edited November 1, 2018 by john dew

[jamespetts]

Thank you for your thoughts: that is most helpful. I have revised the design of the flat version to reduce the number of conflicts at the entrance to the LSWR lines locomotive sidings:

 

 

This has also increased the total number of LSWR specific locomotive sidings from 12 to 16 (including a long double-ended siding into which two locomotives can fit counted as a pair), making 26 in total.

 

The inner (relief) LSWR line is intended mainly as a station headshunt, but it is intended also to be used by the push/pull branch trains, which have their own siding as before. With the new design, the majority of locomotive movements to the turntable will go via the top line, leaving the relief line clear to act as a headshunt when it is not being used by branch passenger trains. The mainline up trains on the LSWR line were always intended to use the inner of the three tracks.

 

As to the number of blocks on the LSWR main lines, the section between the last crossing of the station throat and the scissors crossover is not long enough to have more than one block (measuring 3,013mm on the inner line, as against a maximum train length of 3,186mm, and that does not take into account fouling points). Therefore, I do not anticipate that the flat design will allow trains to wait partly in the fiddle yard while another train departs the fiddle yards, as the longest train would have to wait with the rear carriages still in the station throat, which would be absurd. This is a definite disdvantage of this flat design over the split level design, as the split level design allows trains to wait for a slot in the fiddle yards while wholly inside the fiddle yards, and allows trains to leave the fiddle yards while other trains are entering them, which this design does not.

 

I am not sure that it would be necessary for the preceding train fully to have entered the storage yard siding, since there might be a clear path to the designated fiddle yard road at the bottom of the ladder while the preceding train is still entering a road at the top of the ladder; but I can see that the train would have had at least mostly to have entered the fiddle yard.

 

One other disadvantage of the flat design is that it is much more difficult to deal with the locomotive coal trains with their brake vans - the break van would have to be uncoupled using a pilot engine and hauled aside - another locomotive would have to couple to the front of the train, the brake van would have then to be put into the back of the siding by the pilot locomotive and uncoupled, and the train would then have to be backed into that siding by the train engine to couple to the brake van before departing again. This is not an insurmountable hurdle given that the locomotive coal trains will only run at quiet times, but this is still sub-optimal.

 

Choosing between the flat and split level designs is actually quite challenging. The main advantages of the split level design over the latest flat design would seem to be that it allows trains to enter and exit the fiddle yards at the same time, and allows trains to be queued in the fiddle yards waiting for a free slot, as well as not needing turntables.

 

The flat design has the advantages of not needing gradients (and therefore possibly magnetic assistance for long trains to climb them), having 26 locomotive storage sidings allowing for automatic locomotive changes in the fiddle yards and more locomotive variety, and does not need complex split level baseboards and restricted clearance issues.

 

In relation to Granby's operations - I should be very interested to learn more of them. You write of defending it - I did not mean an attack: I am just keen to piece together how it operates to see whether I can apply some or all of the same principles to my layout.

 

I am quite keen to find out more about the extent to which the conflicts are likely to be a problem in practice with the flat design, which is why knowing more about your layout's operations would be quite useful.

 

Edit: Thinking about the sections issue a little more, I could subdivide the main line into the storage yard at the point when the line leaves the scenic area. This would give 1,331mm inside the fiddle yard for temporary storage for an up train - enough for a few of the shorter trains at least. The same principle could be applied for the down and the relief lines.

Edited November 3, 2018 by jamespetts

[jamespetts]

I have made some adjustments to the locomotive shed facilities on both the flat and the split level versions, as I have realised, looking into the topic, that it would have been unusual to have had a separate road for a water tower (which would have been built into the coaling stage or in stands next to the ash pits), and that I had not left enough room for the coaling stages.

 

Here are the new plans:

 

split level; and

 

flat.

 

Removing the separate water tower line on the LSBSR side has allowed more to be fitted into the engine shed area, including an extra (external) shed road for the LSWR area and an additional siding in the LBSCR area. The road that I had previously allocated to be the LSWR shed's water tower road is retained as a headshunt.

 

As to the coaling stages, the intention is for the LBSCR coaling stage to be a small, level coaling stage with no more than a basic platform, but for the LSWR coaling stage to be a multi-level affair with a substantial incline. I understand from reading another thread on this forum that a coaling stage's wagon road should be 50mm high and have at least 700mm of track leading up to it. This design has 991mm of track leading up to it, giving a 5% gradient, which should just about be possible (hopefully) for a locomotive pushing 3-4 coal wagons.

 

I have also removed the direct access from the coaling stage to the station throat, as I suspect that this is not how an engine shed would have been organised.

 

I have also been giving more thought to the inter-relation between the engine sheds, fiddle yards and a particular design intention of this layout mentioned earlier in this thread but not discussed much recently: the ability to convert it to different areas and periods by changing the rolling stock and making some other, minor changes that can be done in a few minutes, to give, in effect, several layouts in one (after a fashion). The idea is that all that would need to change would be rolling stock (for changes in both era and period), figures of people (for some changes in period), station signs (for changes in area), signalboxes (for changes in area) and signals (for changes in area), the latter being the most complex but achievable from what I understand using a commercially available signal mounting.

 

The backdating should be relatively straightforward (in so far as the track layout is concerned: the difficult part is obtaining the appropriate rolling stock for earlier eras stretching back to the 1910s as planned), but the change of area possibly requires some track layout related thought.

 

The main alternative area that I wish to be able to represent is a main line GWR terminus in South Wales - a pastiche of Swansea had the Victorian era plans to amalgamate Swansea High Street and Swansea Victoria stations been put into action which I will call "Port Tawe". The LSWR lines would become the GWR mainline to Cardiff and London and the LBSCR lines would become a joint GWR/LMS (or, if/when backdated to pre-grouping times, GWR/LNWR) line towards Lanelli and Pontarddulais, for trains on the central Wales line (LMS/LNWR) and the west Wales main line to Fishguard (GWR).  (I realise that the lines are the wrong way around for this - one will have to imagine the western lines diving under the main line to Cardiff just off scene).

 

This gives rise to a few considerations of note. Firstly, the GWR trains to London may be longer than the equivalent SR trains in the Bournehampton designation of the layout. The flat fiddle yards can accommodate 4 trains of >12 carriages (some of significantly more), whereas the split level design can accommodate 2 (both in the orange section rather than the yellow section.

 

Secondly, I know that the ex-LMS services to Swansea Victoria were worked by LMS class 5 4-6-0s in the 1950s and 1960s, but I do not know what worked this line in the 1930s and earlier. The black 5 is 63ft long - the turntable that I had planned for the engine shed in what is in the Bournehampton designation the LBSCR shed (and what would the the LMS or LNWR shed in in the Port Tawe designation) would only be 60ft in diameter (the turntable shown in the diagram is 70ft in HO scale, equivalent to 61ft in OO scale, which is the closest that I could get). This turntable is fine for Brighton Atlantics and any 4-4-0, but would not fit the black 5. It might be possible to squeeze in a 65ft turntable if the extra siding above the LBSCR (or LMS/LNWR) shed is removed. Alternatively, I could just use LMS 4-4-0 compounds for the express trains to Shrewsbury, although I am not sure whether these would in fact have been used: the LMS might just have used 4p tanks.

 

Thirdly, for the Port Tawe designation, there would be more traffic coming in from one of the lines and reversing to go out to the other lines. Also, there would be GWR traffic on the yellow lines as well as the orange lines, whose locomotives would need to use the GWR engine shed (the LSWR shed in the Bournehampton designation). This would involve a greater use of platforms 4 and 5 from the yellow lines, which might make the single lead crossing inadequate (this was originally designed with a double crossing in a much earlier version of this layout - but I fear that there is no longer space for this given the new positions of the engine sheds).

 

In any event, I should be grateful for any thoughts that anyone may have on these developments.

Edited November 4, 2018 by jamespetts

[john dew]

Hi James

 

Sorry for the delayed reply. I am, perhaps, over conscious that Granby has developed in a rather disorganised fashion hence my facetious use of "defend". I have absolutely no problem discussing the operational compromises I have had to introduce. Quite the reverse in fact if it others can learn from my experiences.

 

 

Your storage yards

 

I have been able to get the full resolution version: thank you for uploading that: that is most interesting. I have seen your suburban working videos showing, I think, kickback working, but I am not quite sure that I follow how your work your express passenger, milk and parcels trains.

 

Let me see if I can understand the sequence: the milk/parcels train departs from section 688 on the up relief at E or the up main at F passing through the crossover. It does whatever it is supposed to do in the station area and arrives back in the storage yard at C. It then crosses over to the down line using the crossover and arrives at 674. It is from here that I am a little unclear - does the locomotive go to 675? If so, where does it go from there and what happens with the down freights from 687 and 672? Does it go through 685 to get to the turntable? What if the Phewlli train is in? Presumably, it then goes to the turntable - but where does it go after that? Does the same or a different engine re-attach to the parcels/milk train at 674? If so, presumably it goes back through D and arrives at G, crossing over back to 688 - but what then happens to the locomotive?

 

 

 

The Milk and Parcels sequence is rather complex  There are two separate trains involved. Currently the locos are not turned in the Storage yard.

Lets assume the Milk Train (Grange 6832) is in the down storage block 674 and the parcels train (Hall 4905)  is in the Up storage block 688l. The Down Milk train leaves 674 arrives at Granby,  and picks up 2 tankers.. Meantime the Up parcels train leaves 688 and passes through Granby dropping off two vans......this is quite a quick manouvere. The Up Parcels train then leaves Granby arrives in 674 as you describe above. The Hall uncouples and passes though 675 Loco to [G] reverses through the Xover to 676 Milk Loco spur to await the arrival of the Down Milk Train in 688. When the Milk train arrives the Grange immediately uncouples and proceeds via C and the storage Xovers to 674 to couple with the Parcels train. At the same time the Hall leaves 676 Loco Spur to couple with what will become the Up Milk Empties.

 

Basically the Hall only travels in an Up or Anti clockwise direction and the Grange in a clockwise or down direction but trains travel in both directions. I do something similar with the Express Passenger trains. 

 

Now I have got the TT approach roads sorted and the TT working reliably I may eventually modify the routine so the locos are turned and return to their original trains for the return journeys  

 

I think that I understand the routine for the Phwelli trains at D5 (it is interesting that a fiddle yard only locomotive ends up being needed for this - quite a unique arrangement!), which is quite an interesting way of doing things, but I notice that you only do this for one rake of carriages at a time as it requires in effect two whole sidings for one train, which is potentially problematic for a layout that is somewhat limited in space and whose owner rather likes to maximise fiddle yard usage and thus train variety.

 

I actually run a number of different suburban trains on out and back routines into D5. The B Set you can see in U5 665 runs from there through Granby to D5 and there two 4 carriage sets stored in sidings adjacent to the Engine Shed. Using a pilot in the D5 area means I can prepare trains while running trains into and out of the other storage sidings.  

 

 

Hope this isnt too confusing.........my desire to run a wide variety of trains without them all just doing circuits does sometimes confllct with the KISS principle!

 

Regards

 

 

John

 

 

 

[jamespetts]

Thank you - that is very interesting and helpful. The complexity, in fact, is very helpful, as it demonstrates just what complex shunting is possible in a fiddle yard.

 

Can I ask - how reliable do you find this, and what sort of frequency of trains can you obtain with this sort of operation?

[john dew]

Provided locos are well maintained I have found TC is super reliable in terms of shuffling locos from one siding to another.........it cant be totally un-supervised, a loco will eventually get one of the dogs' hairs in the pick ups ........but in terms of reliability its in the very high 90s.......2% error rate perhaps.

 

The area that requires the most supervision is uncoupling and coupling. A momentary hesitation will affect TCs time and distance calculation and the loco will over or under shoot the magnet. The more frequently you run the routine with the same locos and stock the more reliable it becomes but I would say the failure rate could be 10-15% which means you have to keep a very careful eye on that stage of the procedure. I wouldnt uncouple/couple in a hidden yard. I test the procedure....after uncoupling I have the loco run clear an inch or so. after coupling I have the loco move the train an inch.......so its then easy for the hand of God to assist.

 

You do have to do an awful lot of testing.......I frequently have stop markers at differing distances for specified locos and double up the magnets

 

Cheers

 

John 

[jamespetts]

Interesting - thank you. What sort of service frequency can you maintain with so much shunting in the fiddle yards?

[john dew]

I am getting confused about the three dark green LSWR lines. If I number them 1-3 from left to right I had imagined that 1 is Down Main, 2 Up Main   and 3 Up Relief/Head Shunt.........is this correct?

 

Secondly I assume a train enters one of the ladder of storage sidings....the loco uncouples.....a new loco comes from the blue loco sidings and couples.....leaving the old loco trapped until the train departs? It seems quite a complicated and not very direct route from loco sidings to storage sidings?.

 

I think we will have to give some thought as to how we can get TC to release the route containing the storage ladder turnouts until the incoming train has not only fully entered the storage destination block but also completed the schedule ie stopped.

[jamespetts]

Yes - your summary of which of the three dark green lines is which is correct. Likewise, your assumption regarding the planned operation of the LSWR fiddle yard area is also correct. (This does have the effect that more locomotives are required; but the corollary of that is that more locomotives are usable, which is a happy corollary, I think).

 

The route from the locomotive sidings to the storage sidings does require either two or three reverses for all but the very top of them, that is true. I could not think of any layout that would fit enough sidings into the space that does not require this. Is there such a layout, do you think? I do not think that the amount of reversing/shunting is any more than you have described for Granby (which seems to work rather well from the videos)?

 

I am slightly confused by your last sentence - do forgive me: do you mean that we want TC to wait until the schedule has finished completely, or we want TC not to wait until the schedule has finished completely, but only until the train has cleared all conflicting routes, before allowing the next train to run? I had thought that TC would automatically do the latter, and I am not sure why we would need it to do the former - can you elaborate?

 

Thank you again very much for your thoughts: they are much appreciated.

[john dew]

Interesting - thank you. What sort of service frequency can you maintain with so much shunting in the fiddle yards?

 

Not sure what you mean by frequency? The uncoupling routines happen separately and the released locos dont have to be moved immediately. The milk train only runs twice a day.

 

There are choke points at both storage entrances and the station throat but they can be managed

 

I do like to have a lot of locos on the move at the same time but in a controlled manner ie not to many complex manouveres at the same time. The LMS suburban routine involved 4 locos plus the siding had to be released by moving the B Set to D5 thats two more locos. In the background I think I had the down freight circuit running 3 locos but an ultra safe roundy roundy. I could have added the autotrain on the lower level branch!

 

I have a few "party pieces" like that where two or three unrelated routines can be linked in a macro........my challenge is to integrate all the routines and individual schedules into a realistic 24 hour timetable.....I start and keep getting diverted.

 

John

[jamespetts]

Ah, the 24 hour timetable - that is a happy thing indeed! I should very much like to have one for my layouts (indeed, actually a 7 day timetable, with a separate Saturday and Sunday service, with excursions on the Saturdays, commuter trains on the weekdays and so forth). Myriad are the joys of TrainController!