Help with my 3 level double track up and back.

[96RAF]

Have a read of this guide to reverse loops . . .

https://uk.hornby.com/community/forum/faq-do-i-need-a-reverse-loop-module-and-how-do-i-install-one-322539

[Weymatt]

Hi 96 RAF

On reading your tutorial am I correct in thinking you don't have to have a turnout within a closed loop, as in the classic, down one rail and back to the start, but only isolated track longer that the trains you use on meeting the opposing phased tracks?

Oh how simple that would make my situation.

Cheers

Matthew

[Fishmanoz]

Hi Matthew, I’m having a little problem understanding what you mean but can I make a couple of points for you:

• an RL exists if and only if it is possible to start at some point on the layout, trace your way around the layout and come back to the initial point facing in the opposite direction
• does an RL know or care if there is a change of level within it? No it doesn't.
• an RL does care if trains can be both entering and leaving its isolated section at the same time. Therefore, while making sure the section is longer than your longest train, don’t have it excessively longer.
• must the isolated section in an RL contain a turnout? No, there is no requirement for this. In fact, control of the isolated section is simpler if it doesn’t due to the “entering/leaving at the same time” restriction

Now in your layout as shown, there are 2 obvious RLs. They are in the top layer (shown in the middle) and are the green loop and the blue loop. These RLs are contained fully within the top layer and do not include the up or down tracks to the other layers.

You must include isolated sections in each of these loops, both sections being part of the loops and must be longer than your longest train. They can be anywhere convenient within the loops.

Does that help?

[What About The Bee]

Hi Matthew 👋.

There are a thousand ways to skin a cat. The cat doesn't like many of them. Here is how I check for return loops. Not "the" way, just the way I do it.

Take out two colored pencils. The colors don't matter, but they should contrast. Say red and blue. Pick some spot on your layout. Pick out one of the two rails, say the right rail. Right, Red. Pick up red and start tracing your right rail. Keep going in the same direction until you have all the right rails colored red. Do the same for the left rail, only this time in blue. Left, Blue.

Every time red meets blue, you have a polarity issue, which requires attending to. Fishy already spotted two, and you should find those quite readily. Are there others? Consider frog polarity at each point/turnout. When you trace your rails, red will meet blue at every point/turnout. Every one.

I get the sense that you are just starting out on your model railway adventure. If so, welcome aboard!! If not, please disregard the following. Starting with a very large and complicated layout, such as the one you present, is bound to prove a monumental task that will burn out the person attempting it. It is entirely too big for a relative newcomer. Start smaller and learn all the tasks required, such that when you do understand what and how, you can build the layout you present.

Apologies to all cat lovers. No cats were skinned in the writing of this post.

Bee

[Weymatt]

Hi Bee

I have in fact done something similar on my top level as shown in previous post, my problem is what to do about it.

You are correct regarding such a large layout, as my wife keeps telling me, so i may just initially start on one level.

Thanks for your advice, I will digest and reconsider my options.

Many thanks

Matthew

[Weymatt]

Hi Fishmanoz

Thanks for your help I will inspect my layout and take note of what you are saying.

I have printed out both yours and Bee's replies so I can consider them further as they both contain the information that I require to help me along.

Many Thanks

Matthew

[37lover]

Weymatt,

I am relieved to read that you are gong to digest and reconsider your options, a sensible decision. I have followed this thread but have struggled to understand your original very ambitious plans. You have suggested three levels but didn't actually confirm if they were stacked, or side by side. If side by side why have different levels? If stacked then you would need a lot more vertical clearance between each level to reach in! I look forward to seeing further posts from you once you have reviewed your plans.

[What About The Bee]

I have in fact done something similar on my top level as shown in previous post, my problem is what to do about it.

 

 

Hi Matthew 👋.

Let us suppose the most simple of situations. We have a straight run of track. Perfectly straight, no points, nothing. Just a straight.

In the middle of that straight is a gap. This gap provides electrical isolation. You could use insulated rail joiners here, but this is not necessary for our experiment.

We will wire this layout such that when at the northern end, headed south, the right rail is +. When at the southern end, headed north, the right rail is +.

Now if you are following along, you will notice that at the gap + faces -, for both tracks.

If you were to command the locomotive across the gap, you will electrically short the controller at the gap, because + is connected to -.

Full stop. Draw this and study it until you understand what I am showing you. This is an electrically short. It removes all the air out of the layout balloon.

Suppose we had a way to flip the electrical polarity (change + to -, and - to +) when we wanted to go onto the track after the gap. Then, when the locomotive crosses the gap, + meets + and - meets -. Naturally, you would need this on both the southern and northern end of our straight.

In direct current (analog), you will require a double pole, double throw switch on both the northern and southern end of our straight to make this work. Full stop, if you do not know what a DPDT switch is, go get a diagram from the internet and learn how they work. There are literally thousands of explanations on the internet of how they function. You should be able, at the end of this exercise, be able to drive from the northern end to the southern end, and visa versa, without creating a short. Keep going until you can draw the diagram of the wiring.

Now if you are in Digital Command and Control, there are far more elegant solutions. In DCC, you command the loco, not the track. A device, such as a frog juicer, automatically switches the track polarity for you. Before you jump to a frog juicer, though, learn the basics.

Bee

[96RAF]

Some RLMs can in fact work on DC as well as on DCC I am assured. I have not tried it but the theory is elegant.

[What About The Bee]

Hi 96RAF

At this juncture, I am making an attempt at showing WeyMatt what a short is and the very basics of how to deal with it. After an extensive exhange of messages, we have at last arrived at the root of WeyMatt's issue, to wit, polarity.

We shall not speak of his temerity in disobedience of SWMBO, but following the Admiral's direction is advised 😉

I know every lad here can draw the circuit. The ladies too. What I am trying to do is teach WeyMatt how to do it. There are indeed 1000 ways to skin a cat. Let us show WeyMatt the first way.

Bee

[CORKY.]

If you need help with traction, DCC Concepts supply sets of magnets for locos, and a sort of metal underlay called PowerBase, and TODAY ONLY Rails of Sheffield are selling at 35% discount

[Weymatt]

Hi 37Lover

Below is a plan of my structure for each level. This will be built initially without the turquoise Cross members so that all areas are reachable from either around the outside area ie 24" or 30" outside clearance or the 24" passage created via the turquoise area this means there will only be a maximum reach of 2ft to any area.

I will then do the track work on level one, without what goes on the turquoise area but mapping out what will eventually be built there.

Yes the levels will be on top of each other using the same procedure so the 12" hight restriction will not come into play as the lower level is completed with the exception of the turquoise which will be built 2ft at a time on each in a "back fill process".

I hope this process is making sense to you!

Many thanks for you interest.

Matthew

[Weymatt]

Hi Bee, "again"

Thanks again for your help I think I understand what you say after reading you last post.

I have in fact got some frog juicers that I tried to use on an insulated frog point without success and I phoned the supplier who told me you can only use them on electro frogs, is this correct?

I am sorry I seem to have caused a little reft between yourself and 96 RAF !!! Let me assure you all I am appreciative of all the reply's I receive.

Cheers

Matthew

[Fishmanoz]

Hi Matt, while in theory you could use a frog juicer on an insulfrog point, in practice you can’t because they are not made electrically in such a way that you can.

Going back to the task Bee has given you, I think I know where he is going with it (now have 2 breaks in that long straight track) but will leave him to do so with you.

[96RAF]

Over to you Bee. Sorry to have trodden on your toes. It is true though that you cannot change the polarity of a plastic frog.

[What About The Bee]

Hi WeyMatt

I think 96RAF and I get along just fine. 96RAF, naturally, may speak for himself.

Technical discussions are not indicative of personal rancor. Model railways have many facets and we are always learning, all of us. Some are further along the curve than others. In simple fact, I am quite appreciative of the vast knowledge base displayed. The discussions here are meant in a genial sense. Treat them thusly, and you too will get along!

Now go do your homework and present us with the diagrams 🙂. We will get you to the next level but your cooperation is needed.

Cheers

Bee

[Weymatt]

Hi Bees

I was totally Tongue in cheek with my comments, in fact I am amazed how all people on the forum are so helpful. I am sorry to have upset anyone, please accept my apologies.

Matthew

[Weymatt]

Hi 96RAF

Please do not drop out of this discussion I need all the help I can get.

My comments were totally tongue in cheek.

I am trying to take on the information people are giving me to the best of my very limited ability.

Thanks again for everybody's help.

Cheers

Matthew

[What About The Bee]

Hi WeyMatt

The purpose of the exercise is to get you to understand polarity and how to control it manually. Automation happens after that!

No one is slipping out of the conversation. I'm also fairly comfortable asserting that there has been no offense taken in this thread, by anyone or by any means! You are just fine as you are.

When you present the requested diagrams, there will be many who will chime in.

Probably to correct me 😉.

Bee

[ModelerXYZ]

So you have some Return loops? To fix this issue on a DC circuit, put Insulated rail joiners on a section, and then switch it with a Double Pole Double Throw Switch. I do that on my triangle as well... But thats a whole different issue. Such Loops do exist in Real life, there was a double track one at Didcot power station before it was removed.

XYZ

[96RAF]

The RLM FAQ document tells how to recognise a reverse loop which as seen can be a loop or a Wye or be effectively hidden in more complex track work including past points.

And as Bee correctly states you get the basic concept on board of tracing the rails round your track plan to see if it comes back on itself then you will see why you need to have a means of swapping the polarity (DC) or phasing (DCC) to prevent shorts.

Using a truck with coloured tape can be one way of doing it on the actual track or using coloured pencils on your printed track-plan. If red rail meets blue blue for instance then you have a reverse loop scenario to fix.

The insulated rail joiners are fitted at strategic locations determined by the reverse loop track geometry and to suit your longest train in order to give you a safe haven where the train can be placed to allow the polarity/phasing change to be made.

No I hadn’t fallen out with Bee but at times too many cooks spoil the broth or in our case too much information can confuse the OP rather than help them.

[Weymatt]

I have had no feedback since last Wednesday.

Has everyone fallen out with me?

Matthew

[P-Henny]

Matthew,

On page 3 of this thread you said you would consider your options, then you went largely quiet apart from a couple of posts that seem unrelated to the information members have given in replies made on pages 4 & 5 that gave a lot of information regarding Reverse Loops and Polarity. So far (unless I have missed them) I haven't noticed any follow up from you regarding the contents of those replies. I should imagine that the members that have been contributing technically in this thread are taking the view that the ball is in your court and awaiting some form of feedback on those posts before chirping up again.

[What About The Bee]

Has everyone fallen out with me?

Matthew

 

 

Absolutely not! Not at all.

After quite a bit of conversation, it became quite clear that the biggest assist you needed was understanding polarity. Quite a few spotted this. Understand that we are not judging you as a person, we are simply assessing technical level so as to provide the best help that will be most meaningful to you!

You were left with a simple puzzle in polarity. Some DPDT switches and a simple straight track. This puzzle, WeyMatt, will absolutely help you directly to the next level of understanding.

We await your solution and diagrams. Patiently and with hope that you can solve it. We have confidence that you can solve it. I would suggest to you that you try to solve it. Why? Because you need to understand polarity to make your layout work.

Bee

[Weymatt]

Hi All

I certainly am listening to you all but there is lots to assimilate in the various posts.

I Include below a sample layout where I have followed the tracks around and I use red and black markers to indicate the polarity of the rails, and come to the dreaded "short" where i then include a break, marked in green, and a rail gap at both ends, protected by a RLM.

I have downloaded "Do I need a return loop" to study closely.

Many thanks to you all.

Cheers

Matthew