Under bed OO Thomas the Tank Engine layout?

[BroadLeaves]

Certainly the station and crossover can be moved. I just plonked them on the plan to show their approximate location. It was a basis for discussion only.

Regarding the access inside the tunnel, have you considered making it removable? If there's a derailment, you just lift the whole thing off, retrieve the rolling stock and put it back down again. See https://www.rmweb.co.uk/community/index.php?/topic/120848-little-muddle/page/498/#comment-4714351 and https://www.rmweb.co.uk/community/index.php?/topic/120848-little-muddle/page/498/#comment-4714360 for an idea of what I'm suggesting, but with a tunnel rather than some houses.

You can put a point on a slope. It's not really recommended, but you can do it. What you absolutely cannot do is put the point on a *change* of slope. You can bend track vertically (as you must to at the start and end of the slope). You simply can't bend points that way. If you can do without it, losing the point in the elevated goods yard will make life a lot easier. You could perhaps use the extra space gained to add more interest in other ways - a nice big working goods crane perhaps, so things can be lifted in and out of wagons.

 

[Fold]

As I thought then - I'll work on the assumption of no points and siding in the goods yard, and as you say, something else interesting could go up there (my eldest says it will be where all the snow and Santa's workshop is... so that might be a thing that's happening!)

 

I'll also bear in mind a removable hill top when I start getting to grips with building this thing.  It seems like it would be fairly straightforward to manufacture and would free the scenery from practical board edge constraints. I migth also move the train tunnel to the bottom left of the track so the incine goes through a tunnel - since that part of the board has relatively little going on.

 

So the only question now is the one about insulated track/fishplates, if anyone can help?

 

Thanks again @BroadLeaves!

[BroadLeaves]

Below is a corrected track plan with the point removed as per above, and buildings removed for clarity.



You need two isolating fish plates, one on each side of the track, as indicated in red. The exact location doesn't need to be in the middle, but they *must* be on that stretch of track between the two points.

You'll need two controllers, "orange" and "blue". The blue controller connects to the inner track as shown. The orange controller connects to the outer loop as shown, but there need to be two more connections, shown in green, one to the elevated goods yard siding and one to the top siding near the dock. The reason for this is that the points are self-isolating - they only pass current in the direction they are switched. Without the extra link to the dock siding, there is no way to ever drive a locomotive onto the upper siding. Without the extra goods yard link, the goods yard will only have power if the curved point is set to the loop, which might be a bit confusing. When connecting the two supplementary feeds, you'll need to make sure that you connect "same rail to same rail", to avoid a short circuit. The easiest way to do this is to note which wire connects at the main connection and then just follow the rail round with your finger!

With that in place, all track is powered by one or other controller, regardless of how the points are set and there is no possibility of any track being powered by both controllers at once. The orange controller always controls the outer loop, the elevated goods yard and the dock. The blue controller always controls the left-hand half of the inner loop, the inner station, the engine shed and inner siding.

To drive a train from the outer to the inner loop, set one of the cross overs to curved and the other to straight. Drive the train until it goes past the red isolating break, at which point it becomes controlled by the blue controller. It's best if the blue controller is turned off at this point. Once the locomotive gets all wheels past the break, it will stop. Change the curved cross over back to straight and turn on the blue controller. The train can now go round the inner loop. 

To drive a train from the inner loop to the outer loop, it's just the same, but this time, you start with the orange controller turned off, and drive the train towards the curved cross over using the blue controller past the isolation break, where it will stop. Turn on the orange controller and use that to drive the train onto the outer loop, and then set the cross over back to straight.

[Fold]

Legend. I'm going to print a label with those instructions to transfer between loops so it can be stuck to the side of the layout for future reference!

 

3 hours ago, BroadLeaves said:

The orange controller always controls the outer loop, the elevated goods yard and the dock. The blue controller always controls the left-hand half of the inner loop, the inner station, the engine shed and inner siding.

 

I'm probably missing something but which one controls the right hand half of the inner loop? This seems conspiciously absent in your  list!

 

3 hours ago, BroadLeaves said:

When connecting the two supplementary feeds, you'll need to make sure that you connect "same rail to same rail", to avoid a short circuit. The easiest way to do this is to note which wire connects at the main connection and then just follow the rail round with your finger!

 

As in, both the supplementary feeds need to connect to the same rail as each other, or to the same rail as the orange controller connects to?

 

For context the controllers that come with Percy are the attached. The pins plug in to a special port on a short straight.

 

Assuming these are usable, will I need to splice additional wires from one or both of the wires?

[Kris]

You can splice in extra wires or you could use something like these https://uk.Hornby.com/products/digital-electric-point-clips-pack-20-r8232 but don't use these, they are just very expensive sprung wire. 

[ITG]

A few comments….

Many modellers report on this forum that set track curved points are more prone to derailments than straight ones, although some of that issue may be due to running larger locos and/or bogie coaches - thus may not wholly apply to your stock.

Equally, many modellers would opt to use set track curves on such tight radii, rather than flexi. It can be tricky to bend flexi in a smooth curve when so tight a radii.

I echo comments above about small sidings and lack of space/clearance for platforms.

To keep the two loops electrically separate you need insulating rail joiners on both rails between the two points in each crossover. You will need to take steps to ensure it is impossible for both controllers (if you don’t use two controllers, you won’t be able to run 2 locos simultaneously) to be powering the same length of track - which they will be when the crossovers are set to swap from inner to outer or vice versa. This would require some form of switching to prevent this dual power happening - that may be a challenge for young boys to grasp.

Im afraid quite a few things to reconsider.

ian

 

Edited January 24, 2022 by ITG
Update

[BroadLeaves]

13 minutes ago, ITG said:

To keep the two loops electrically separate you need insulating rail joiners on both rails between the two points in each crossover.

Not necessarily. I think the scheme I outlined will avoid short circuits and allows a train to be driven all the way over a crossover without stopping.

14 minutes ago, ITG said:

which they will be when the crossovers are set to swap from inner to outer or vice versa

That's the reason for the insulation break in the right-hand side of the inner loop - precisely to prevent this problem.

[BroadLeaves]

56 minutes ago, Fold said:

I'm probably missing something but which one controls the right hand half of the inner loop? This seems conspiciously absent in your  list!

Ah, yes; fair point! If the top crossover is set to straight. the blue controller does the right hand top section from the crossover to the break. If the top crossover is set to curved, the orange controller does the top section. Likewise, if the bottom crossover is set to straight, the blue controller does the right hand bottom section from the crossover to the break, and if it's set to curved, it's the orange controller again. What that means is that with both crossovers set to straight, the blue controller does the entire inner loop.

 

56 minutes ago, Fold said:

As in, both the supplementary feeds need to connect to the same rail as each other, or to the same rail as the orange controller connects to?

There is a "left" and "right" rail, or as you have two loops, an outer and an inner rail. The supplementary feeds to connect left rail to left rail and right rail to right rail.

This may make it clearer. The red and green are carefully drawn to go to the correct rails:
 

 

The controller you've shown has a connector intended to go directly into a dedicated "power feed" track, which looks like:

and you probably have one of these in the set. For your layout, there's no easy way to use that for the outer loop. You could use it for the inner loop and put it as the bottom left hand straight on the inner loop. For the outer loop, you can either solder to the rails or use power clips like this:

which clip directly to a piece of rail (every bit of settrack has handy holes in the sleeper webbing for just this purpose). Either way, some sort of splicing will be required as the layout will need multiple power feeds. That's not a reflection on the design - it's true of almost every layout that is more than complex than a single oval and a siding.

Having said that, I'd forgotten about point clips and @Kris is correct in that they are just an expensive way to buy some short bits of sprung metal, but by the time you've bought the cabling (and maybe power clips), drilled the holes in the baseboard, soldered it all to the sides of the rails and so on, it may well be a better option. If you use the point clips, you would put two in the point to the elevated goods yard and two in the point on the right hand dock siding. You wouldn't then need any supplemental feeds at all. Just connect the two controllers to the left hand curves of the loops as per the orange and blue arrows.

Edited January 24, 2022 by BroadLeaves

[Andy Hayter]

One thing that has not been mentioned but which you should at least think about:

The underside of beds and the floor beneath have a nasty habit of attracting dust.  Dust and model railways will create disappointment as it will get into point blades and into the electrical pick ups on the engines and stop the electricity flowing which means the trains will not run or will stutter around the layout.  

 

I would suggest you think about some form of dust protection when the layout is in storage and it is probably easier to think about it now than after the event.

[RJS1977]

On 21/01/2022 at 11:25, Fold said:

 

I definitely want to have a level crossing but would move it to one of the short edges, saving the width, which means it will go over curved tracks - probably precluding the use of any commercially available kit, 

 

 

Peco Setrack:

 

1st Radius curved level crossing: https://peco-uk.com/products/curved-level-crossing-1st-radius

2nd Radius add-on-unit (to create a double track crossing): https://peco-uk.com/collections/100/products/curved-level-crossing-2nd-radius-add-on-unit

 

(Note that the two together are roughly half the price of Hornby's double track - straight- level crossing!)

 

Peco curves are to the same radius as Hornby curves so the two are interchangeable.

[ITG]

9 hours ago, BroadLeaves said:

Not necessarily. I think the scheme I outlined will avoid short circuits and allows a train to be driven all the way over a crossover without stopping.

Well, maybe so, but surely the position at which the loco passes over the rail break (your red lines), effectively means stopping it, switching that controller off, and turning on the other controller. Messy, especially if both boys are playing in any way other than each keeping to their own loop.

[Fold]

11 hours ago, Kris said:

You can splice in extra wires or you could use something like these https://uk.Hornby.com/products/digital-electric-point-clips-pack-20-r8232 but don't use these, they are just very expensive sprung wire. 

 

11 hours ago, BroadLeaves said:

Having said that, I'd forgotten about point clips and @Kris is correct in that they are just an expensive way to buy some short bits of sprung metal, but by the time you've bought the cabling (and maybe power clips), drilled the holes in the baseboard, soldered it all to the sides of the rails and so on, it may well be a better option. If you use the point clips, you would put two in the point to the elevated goods yard and two in the point on the right hand dock siding. You wouldn't then need any supplemental feeds at all. Just connect the two controllers to the left hand curves of the loops as per the orange and blue arrows.

 

Thanks for the tips - this seems much simpler and, ease trumps cost in this case - I'd also need to buy or rent a soldering iron anyway.

 

11 hours ago, BroadLeaves said:

and you probably have one of these in the set. For your layout, there's no easy way to use that for the outer loop. You could use it for the inner loop and put it as the bottom left hand straight on the inner loop. For the outer loop, you can either solder to the rails or use power clips

 

I have one in each set yes and was hoping to use both. Why do you say the power could be moved to the straight section of track on the inner loop, but not for the outer loop? If the top section of long straight track on the outer loop were swapped for two shorts, could one of these shorts not be the power feed section?

 

11 hours ago, ITG said:

Many modellers report on this forum that set track curved points are more prone to derailments than straight ones, although some of that issue may be due to running larger locos and/or bogie coaches - thus may not wholly apply to your stock.

Equally, many modellers would opt to use set track curves on such tight radii, rather than flexi. It can be tricky to bend flexi in a smooth curve when so tight a radii.

 

This is useful to know thanks, particularly the difficulty of bending flexitrack on the tighter radii - I'll look at the relative cost of buying curves instead of flexitrack especially for the inner loop.

 

11 hours ago, ITG said:

I echo comments above about small sidings and lack of space/clearance for platforms.

 

Even on BroadLeaves modified version?

 

2 hours ago, ITG said:

11 hours ago, BroadLeaves said:

Not necessarily. I think the scheme I outlined will avoid short circuits and allows a train to be driven all the way over a crossover without stopping.

Well, maybe so, but surely the position at which the loco passes over the rail break (your red lines), effectively means stopping it, switching that controller off, and turning on the other controller. Messy, especially if both boys are playing in any way other than each keeping to their own loop.

 

I'm a bit confused now!  BroadLeaves said that with both crossovers switched to straight, the inner loop controller controls the entire inner loop, but ITG you are suggesting that this isn't the case?

 

To be clear @ITG the only modification you're suggesting is that insulated fishplates are put between both sets of crossover points? I can see that this literally makes the loops completely separate at all times. How does switching track work in this scenario?  I'm guessing, to go from the inner to outer, say:

1. the outer loop controller is turned off
2. the points are switched
3. the inner loop controller drives the engine to the point where it just about crosses the point before it loses power
4. the inner loop controller is turned off and the outer is turned on
5. the outer loop controller drives the train across the point
6. the point is switched back to straight

11 hours ago, Andy Hayter said:

One thing that has not been mentioned but which you should at least think about:

The underside of beds and the floor beneath have a nasty habit of attracting dust.  Dust and model railways will create disappointment as it will get into point blades and into the electrical pick ups on the engines and stop the electricity flowing which means the trains will not run or will stutter around the layout.  

 

I would suggest you think about some form of dust protection when the layout is in storage and it is probably easier to think about it now than after the event.

 

Thanks Andy. Perhaps a simple dust sheet can be found in a relevant size. How bad are we talking about though? Would a regular hoover of the points also work? I could ask the cleaners to incorporate it into their weekly routine which might keep everything ship shape. As for the locos and other removable items that are too tall to fit under the bed (trees, cranky the crane etc...), I am thinking of building some drawers into the underside of the base board which would also keep everything clean.

 

[Andy Hayter]

The problem with beds is that we spend 1/3rd of our lives in them.  During this time we shed skin which sticks to the sheets.  When the bed is changed some of this dead skin, plus fibres from bedding and bed clothes then fall to the ground - often through the bed supports.

 

If the dust then ends up on the layout, when you run the locos they will pick up some of it and somehow it works its way between the back of the wheels and the electrical pick up strip, eventually breaking the electrical contact.  Putting the locos in a draw will help but not eliminate the problem.  They will still pick up dust lying on the layout.  

 

A dust cover may well help but it may make some items on the layout vulnerable to being damaged as the cover is placed and removed.  

 

Depending on the bed design, it may be possible to fix a cover to the underside of the bed but do remember to allow good air ventilation to the base of the mattress.

[ITG]

17 hours ago, BroadLeaves said:

The reason for this is that the points are self-isolating - they only pass current in the direction they are switched.

Surely the second part of this phrase is only partly true, in that the self-isolating feature succeeds only in isolating via the non-continuous rail; the continuous rail remains live all the time. So it is possible if two points are placed in a certain configuration , and set in a particular direction, and dependant where the track power feeds are, then both rails will end up being live, completing the polarity circuit. I must admit here that I do not operate either DC or self-isolating points, but I’m trying to find the balance between ensuring the OP understands the issues, but at the same time not over-complicating it. Hopefully!

[BroadLeaves]

18 minutes ago, ITG said:

So it is possible if two points are placed in a certain configuration , and set in a particular direction, and dependant where the track power feeds are, then both rails will end up being live, completing the polarity circuit.

True, which is why the power feeds and isolation breaks are where they are.

[BroadLeaves]

3 hours ago, Fold said:

Why do you say the power could be moved to the straight section of track on the inner loop, but not for the outer loop?

Because moving the inner power feed to the bottom left straight section keeps it between the two crossovers, so that's OK. What you can't do is move either power feed to be the other side of a crossover. However, if you have two power tracks, you can do this, and move the top crossover to the right, and now you can use your two power tracks. This arrangement and some point clips on the two green points will mean no soldering at all.

[RJS1977]

Before we go too much further with the wiring - I'd suggest reversing the left hand siding so that the point is at the top of the board rather than the bottom. This is because as drawn, a train proceeding around the outer loop in an anti-clockwise direction will go straight into the siding and the loco will be trapped at the wrong end. Reversing the siding means the train will set back into it, then the loco can be uncoupled and go off and do something else.

 

The right hand siding (with the kickback) should stay as it is.

 

Two other advantages of this are:

 

1)  Apart from the crossover by the blue arrow, all the points are on one side of the baseboard (so easier to reach).

2)   This removes the need for the point clips at the bottom of the plan.

 

I'm not quite sure why the blue arrow is where it is (should be the other side of the crossover), or why there is a double break shown on the inner loop. I'd have the blue feed to the right of the crossover, and double breaks in the middle of the crossovers.

 

To get from one loop to the other, either wire it up so both loops can be switched to either controller, or, more simply, just set both controllers to the same speed and direction.

[ITG]

7 hours ago, Fold said:

o be clear @ITG the only modification you're suggesting is that insulated fishplates are put between both sets of crossover points? I can see that this literally makes the loops completely separate at all times. How does switching track work in this scenario?  I'm guessing, to go from the inner to outer, say:

1. the outer loop controller is turned off
2. the points are switched
3. the inner loop controller drives the engine to the point where it just about crosses the point before it loses power
4. the inner loop controller is turned off and the outer is turned on
5. the outer loop controller drives the train across the point
6. the point is switched back to straight

Well, I guess it’s all down to how you view the need to switch controllers. I haven’t traced every permutation of train travel through points set in whatever direction, so I bow to what Broadleaves has said about optimum locations for feeds. It seems to me there is a reliance on ensuring the right controller is off at the right time.

Broadleaves - If it isn’t, what happens when a loco reaches the double rail break on the right? When the pick up wheels straddle that rail break, isn’t there a potential for power pick up in opposition to each other? It’s a long time since I had youngsters playing with train sets, but I can’t say I’d be wholly comfortable relying on them to remember to switch controllers on and off, and switch points in alignment.

Ian

[DCB]

I think moving the power clips and isolated section would improve flexibility.  I know there would be times when both controllers would power the same piece of track.  Not a problem with controllers with an off position.  No gpod for Morley...

 

Edited January 25, 2022 by DCB

[BroadLeaves]

5 hours ago, RJS1977 said:

This is because as drawn, a train proceeding around the outer loop in an anti-clockwise direction will go straight into the siding and the loco will be trapped at the wrong end. Reversing the siding means the train will set back into it, then the loco can be uncoupled and go off and do something else.

But surely when the train is going in the other direction, you have exactly the same issue? 

 

5 hours ago, RJS1977 said:

I'm not quite sure why the blue arrow is where it is (should be the other side of the crossover), or why there is a double break shown on the inner loop. I'd have the blue feed to the right of the crossover, and double breaks in the middle of the crossovers.

That prevents two operations which might both be common: 1) Driving a train from one loop all the way onto the other without having to stop and change or sync controllers; and 2) By setting both crossovers to "cross", you get a single loop under the control of the orange controller where the route is the left-hand half of the outer loop and and right-hand half of the inner loop.

The arrangement I suggested is (I think) easier to operate and gives more route variation.

 

5 hours ago, RJS1977 said:

either wire it up so both loops can be switched to either controller, or, more simply, just set both controllers to the same speed and direction.

There's a number of ways that this layout can be wired, and my suggested approach is by no means electrically perfect. However, given the requirements (no use of a soldering iron) and the constraints (the two main operators have a combined age of six), I've tried to keep it simple and remove the need for any separate switches or the need to synchronise two controllers.

[BroadLeaves]

5 hours ago, ITG said:

When the pick up wheels straddle that rail break, isn’t there a potential for power pick up in opposition to each other?

Yes, but see my final point to @DCB above.

[Chimer]

Broadleaves' suggestions for wiring may be (a) clever and (b) work, but I would be nervous of any solution that doesn't include the tried and tested double break on the crossovers.  Personally, I would do this and set up the minimum "cab control" solution, so that each circuit can be switched to either controller.  Then when you want something to change circuits, you switch both circuits to one controller and one child drives it across.  Then change back to separate circuits.  Provided the two DPDT switches required are not set up the wrong way round, it is impossible to have both controllers switched to the same track at once.  Like so .... shown with both circuits switched to Controller 1.

 

 

 

 

 

 

[Zomboid]

On my childhood layout (which was DC) we didn't put any breaks on the crossover, just used the automatic isolation that the points provided, and only used one controller if anything was to cross between the circuits.

 

I don't see anything in this plan to suggest that such an approach wouldn't work here.

 

Nothing bad would happen if both controllers supplied a section of track anyhow. Or it didn't when I tried it.

[Andy Hayter]

Potentially rather dangerous.  If the controllers are fed from the mains, and if one of the controllers is unplugged, The first controller takes 230V from the mains, feeds 12V to the track which the second can then receive as a 12V input and generate 230V which is live at the pins of the unplugged electrical plug.

 

Several ifs there but it can and has happened.

[Zomboid]

Theoretically possible if they're the transformer type, but I doubt that's possible if it's a switch mode supply. Admittedly the standard Hornby ones are transformers. And the rating will be so low that the current available at 230V will be next to nothing.

 

Still several layers of swiss cheese there, so depends on your approach to risk.