I know you guys have missed me, so here's my next unbelievably Electronics 101 question. Yes, I could study wiring books, and I actually have been studying Atlas' Wiring Your HO Layout by Paul Mallery Associates, which is thorough enough and has great illustrations but was written in 1958. I thought it would be a good place to start and it's been useful. But a lot of water has gone over the dam since then, so I figured I'd see if I could rouse some of you guys from your Independence Day torpor.
Below is a crude drawing of my layout with (almost) all the turnouts lettered and each of the three joints for each lettered turnout given a unique identifier. (A1, A2 and A3 for turnout A, etc.) Some turnouts are back to back with others, or back to front, so some joints share a number (B1 and C1 are the same joint, for example, as are G3 and J3).
To see at max resolution, click open, then close, then click image open again. (I don't know why.)
Things to note:
I plan to run a bus line under the mainline, waggling it a little like a radio wave to enable shorter feeders from the branch, spur and yard tracks. I've got 14 gauge for the bus, and 22 for the feeders.
What I want to be able to do in DC is to isolate the yard and the branch from the mainline -- I guess we call that creating blocks -- so that I can run trains separately in all three at the same time, one mixed local up the branch, a bigger freight or passenger train on the mainline, and a switcher switchin' in the yard. The siding is not so important to isolate.
I need to know two basic categories of very specific info, and I wonder -- is it an easy thing to communicate them using the diagram above?
1. Which joints on this diagram should I use isolating rail joiners at to achieve the three main blocks?
2. What connecting wires would need to be added from one rail to another to power the sections that would lose power with the abovementioned isolation?
If trying to get specific wiring info on my layout this way is a fools errand, I'm able to hear and accept that. I'm also able to hear that I should just knuckle under and keep reading until I understand (and venture more recently published books). But I quickly get overwhelmed with discussions of bifurcating potentialities, and I thought, if the Forum Guys knew exactly what I'm trying to do and what my track looks like, it may be as simple as saying, "run feeders down north of turnout D, use isolating joiners at the east rail at B1 and the west rail at D3, and run a wire from this frog or that diverging rail," etc.
Another question is, should I even bother with a bus line for such a small layout (http://cs.trains.com/mrr/f/11/t/287927.aspx)? I do have one DCC loco and plan to someday have more. Easy to do. I drilled holes for the wires to pass through the stringers when I built the benchwork, and I have all the wire and connectors.
Any help appreciated, with my advance thanks. I humbly submit my enduring ignorance in the service of one more functioning model railroad in the universe.
-Matt
Returning to model railroading after 40 years and taking unconscionable liberties with the SP&S, Northern Pacific and Great Northern roads in the '40s and '50s.
I’m old school and for a small layout like yours I would go with block wiring and forget buss wiring.When I wired my layout I went with two conductor twisted pair #19 AWG Bell wire home runs back to my control panel. Each block has a DPDT center off reversing switch.That will work with both DC and DCC. Each home run will handle 2 amps which is more than sufficient for two locomotives in each block.My layout has a total of 28 blocks, the mainline has 10 blocks the rest are yard and sidings. My mainline is 121' so about 12' blocks.
It has worked fine for me for over 30 years both on DC or DCC.EDIT:I thought I should explain the switches on my control panel. They are mini toggles with colored slip on covers on the handle.White is lighting – SPST, ON-OFFRed is turnout control – SPDT, On-OFF-On momentary.Blue is Block Control – DPDT, ON-OFF-ON (Reversing)Green is turntable control - DPDT, ON-OFF-ON (Reversing) & OFF-ON momentaryYellow is Special – DPDT, ON-ON (Track continuous 12 volts DC power for charging on board batteries)Mel Modeling the early to mid 1950s SP in HO scale since 1951My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California Aging is not for wimps.
I use DCC and I would recommend feeders at each 36" of track - more if you have many joiners. So the simplest way to do this is to run a bus wire. But if you plan on having many DC blocks, then a common bus makes no sense. Looking at your layout I can see two locos running, one on the mainline and one on the yard. Three blocks should suffice. So 3 sets of bus wires maybe?
Simon
snjroyI use DCC and I would recommend feeders at each 36" of track
I use DC, and have also found that feeders every 36 inches even in the same block is a very good idea.
-Kevin
Living the dream.
If you're going to run DC locomotives, the best thing to do is to wire the layout as two-cab DC. You power each block with a DPDT center off switch. Two wires run from each block to its own switch. You can assign any block to either cab, or shut it off. True, you can't run more than two trains at once. I don't like to run more than ONE train at once, so I don't see the point.
You've got a lot of what appear to be gapped rails--too many for me. For example, D, E, and F should be just one block. The pink "main" over on the left, should also include at least the two switches (G and A). C and B should be just one block. The two J switches should be a single block. That crossover setup in the lower left just might should be left alone. Some thought might resolve that.
One of the ways of figuring out block placement is to imagine running trains on it. Will it work?
Looks like you then have about 15 blocks. That's 15 switches laid out on a track map.
I wouldn't use the Atlas switches. They're too big and too limited. Just use "regular" toggle switches.
You can use really teeny wire as a drop from the rail above to down below. 22 gauge, or even smaller. That's because you will use a VERY short piece of it. Below, you will connect to the bigger wire, and run back to your DPDT's. 14 gauge is not a bad choice, though you could likely go smaller. This all assumes you're soldering the 22 gauge wire to the rail. You might also consider soldering SOME of the railjoiners. Every section of rail that ends in an unsoldered rail joint should hae the 22 gauge tap wire. You should never depend on slide-on rail joiners for electrical continuity.
When you want to run DCC, you replace one of the power packs with you command center. MOST people will also suggest you make sure to disconnect the other power pack, just in case.
I recommend getting a book on layout wiring. Kalmbach has one out right now:
https://kalmbachhobbystore.com/product/book/12491
I used Westcott's book from half a century ago--not much has changed for DC wiring:
https://www.amazon.com/Railroad-Wiring-Everyone-RAILROADER-LIBRARY/dp/B0028J0Z8I/ref=sr_1_6?Adv-Srch-Books-Submit.x=32&Adv-Srch-Books-Submit.y=8&dchild=1&qid=1625427899&refinements=p_27%3Alinn+westcott&s=books&sr=1-6&unfiltered=1
And read them. Most everything we're telling you here is in there. And much more.
Ed
crossthedogBelow is a crude drawing of my layout
By the way... BRAVO on the quality of your "crude" drawing.
It was easy to understand and interpret. The addition of an easy to interpret drawing will always get you better answers.
7j43kYou've got a lot of what appear to be gapped rails--too many for me.
Woops. Sorry, Ed. None of the joints are gapped. I just drew them that way so we could talk about the joints and see the locations we were talking about. The turnouts from the main into the yard/branch and all the turnouts (curved and straight) inside the yard are so far joined only with rail joiners. The west side of the mainline is pretty much all soldered both rails at each joint, except the west siding turnout. I wanted to get all this good info before I added gaps or plastic rail joiners or dropped any feeders.
All these responses are very helpful, and especially your assesment of what blocks make sense.
In reading back all the way to Mel's response, I keep wondering if there's a piece of this I'm not correctly imagining, and it's about the location of the DPDT switches. If the switches are on a central panel, then how are they wired to the block's rails? Because the feeders have to be very short. So when we talk about block wiring, are we saying that each block has its own bus that runs out from the DPDT switch on the panel to where that block's feeders come down?
Yes, okay, I will read more books
crossthedog If the switches are on a central panel, then how are they wired to the block's rails? Because the feeders have to be very short.
There is no need for the wires from the DPDT CO toggle to the track to be very short.
Yup, read more books. It's good for yuh!
In answer to your question:
The RAIL feeders should be very short. That's because they're very small. And that's because big wires soldered to your track look stupid.
Once those teeny wires get down below, you can connect them to the bigger wires that travel farther. In this case, to the center two terminals on your DPDT center off switches. Those wires feed power to each and every block you are creating.
You might find that a block has three track sections, each with two wires hanging down. You've got to "tag" each of those three with your fat wires.
So now you have two wires from each DPDT center off (center terminals) to each block. HOORAY!
What's next?
I'm gonna be mean, and tell you to look in the books. NOT because I love being mean (which I do), but because they explain it much better, with pictures with circles and arrows......
Persevere, Horatio. Because when you've waded through this once, you look back and think: SO obvious.
Remember when getting a spoonful of Cheerios into your mouth was a challenge? Not anymore, I'll wager. Same thing.
We'll help you out! But not with the Cheerios; you're on your own there, pal.
LastspikemikeTwo wire Block wiring is parallel wiring. Two wire bus wiring is series wiring for most of the length of wire.
You need to post a diagram to explain this.
"Series wiring for most of the length of the wire" makes no sense.
Matt,
The thing Mike is trying to talk about is "common rail" wiring. In this case, the block control switch only controls ONE wire to the block, instead of the TWO I described. Some people like common rail, some don't. I don't.
Get those books! Then you can read all about it yourself.
7j43kSome people like common rail, some don't. I don't.
I also dislike common rail wiring.
We have had discussions about which books are the best for learning the ins-and-outs of DC wiring.
Outcomes of these discussions are that there are a lot of books out there, and none of them describe wiring the way Sheldon or I do it, and Sheldon and I approach wiring differently from one another.
For my suggestion, I think "HO Primer" from Kalmbach has a good chapter on the basics of DC wiring, and is a good place to start.
Linn Wescott's and Paul Mallory's books are excellent, but are far more complicated than is needed today. If you were going to build a layout that complex, the clear choice today would be DCC for most people.
Some random comments on DCC aspects:
1. On books, I liked the Kalmbach "The DCC Guide", which covers most subjects, including wiring. I have edition 1, which is fine. A couple of favorite websites were useful for more detail:
https://wiringfordcc.com/track.htm
Wiring for DCC - DCCWiki
2. On power to track, I relied on (a) soldering nearly all rail joints, then (b) adding feeders at 6' max spacing. (Occasional short (unsoldered) rail pieces and turnout parts got their own feeders so all rail was powered via a soldered connection.) That spacing means that the juice from a feeder to a loco has to travel no more than 3' of rail, since the loco is always within 3' of a feeder. I had seen that (for HO, nickle silver rail) as a guide in more than one place. After installing, do read about the DCC setup "quarter test" to ensure the setup is adequate for the booster (or subdistrict circuit breaker) to sense a short (and trip) on any piece of rail on the layout.
Paul
Modeling HO with a transition era UP bent
peahrensThe Kalmbach "The DCC Guide", which covers most subjects, including wiring.
I read that book while working on a friend's layout with DCC. It was probably the first edition of the title.
I found it very helpful.
There is another Kalmbach book, Basic DCC Wiring, that sounds similar in content, but I have not read it.
Lastspikemike Common Rail and bus wires take power to all locomotives through just two wires: the current draw adds up in the bus wire(s). That's in effect wiring your powerpack in series (until the very end of course, each pair of feeders and each locomotive is in parallel). All of the electrical load is carried by the bus wires all of the time.
Common Rail and bus wires take power to all locomotives through just two wires: the current draw adds up in the bus wire(s). That's in effect wiring your powerpack in series (until the very end of course, each pair of feeders and each locomotive is in parallel). All of the electrical load is carried by the bus wires all of the time.
Wiring in series is setting up multiples of the same two-wire electrical item (light bulb, resistor, capacitor) with the output of one connected to the input of the next.
Here is an example:
Note that ONE thing cannot be wired in series. So how is ONE powerpack wired in series, Mike?
7j43k So how is ONE powerpack wired in series, Mike?
Ed,
I am 99.9% sure you understand all this already.
A complete electrical circuit is a power source, conductors, load, and a pathway for current to return to the power source through the load.
Series circuits have only one path for current to flow through the load(s).
Parallel circuits have seperate pathways through the loads, and will apply equal voltage potential to each load.
Series/Parallel circuits combine these features.
It is obvious that this is not understood by all.
Oh, I see.
It's another word for "connected". So Mike is saying that the power pack is in series with the layout wiring. Or something.
Note that, using your description, as soon as two block toggles are on at the same time, the system is no longer "in series".
I had the impression that Mike was trying to explain the difference between regular two wire block wiring and common-return block wiring. And that he thought the difference was that the latter was somehow "in series". I guess with that power pack he mentions.
7j43k So Mike is saying that the power pack is in series with the layout wiring. Or something.
I have no idea what he was trying to say... or something.
I asked for a wiring diagram, and he questioned my intelligence.
LastspikemikeIf thought experiments are difficult for you I suggest you draw a diagram.
Whatever.
Hi guys. Let's take a deep breath. I think Mike's comment about the thought experiments may have been directed to me, not to Kevin, and I didn't take it negatively. I view all this feedback as people trying in good faith to help and share their experience. And I'm going back through all the replies repeatedly, reading more carefully each time and getting a bit more of a picture that -- by necessity -- is a sort of patchwork or mosaic of many members' visions of how things should be.
Thanks again.
It's not a large layout, so it should not be rocket science. Figure out how many locos you want to 1) sit on the layout; and 2) operate at the same time. Then figure out the rest from there. If you are only speaking of one or two locos, I would refer to the KISS principle. And do consider going DCC full-time. That will simplify things a lot.
One thing is for sure, your DC/DCC switch should apply to ALL of your layout, not just one question. Locos crossing a DCC section to a DC section will smoke, including the diesels .
crossthedog Hi guys. Let's take a deep breath. I think Mike's comment about the thought experiments may have been directed to me, not to Kevin, and I didn't take it negatively.
Hi guys. Let's take a deep breath. I think Mike's comment about the thought experiments may have been directed to me, not to Kevin, and I didn't take it negatively.
Yes, Ed is right, you need to figure out operating scenarios in order to define your blocks. The good news is that, it's quite easy to add a block later if you find that you cannot do the operations you want. You need at least two blocks on the mainline (in red in your picture), and one for the yard. If you put a passenger station inside the North siding, you could put a block pretty much parrallel to the siding (between A2 and b2). That way, you could run one passenger train, and one freight, with one resting on a siding while the other passes by... And both could sit while you do some switching. Other gaps would be C3 and G3 for the yard.
Anyway, just a thought.
snjroyYes, Ed is right, you need to figure out operating scenarios in order to define your blocks. The good news is that, it's quite easy to add a block later if you find that you cannot do the operations you want. You need at least two blocks on the mainline (in red in your picture), and one for the yard.
It's probably buried back in one of my replies or the original post, but I think I did mention that I already know what ops I want and it's pretty straightforward:
I don't envision running all three at once, but certainly the mainline train would be running continuously while I spot cars up the branch or build trains in the yard.
I had thought three main blocks for all that, just wasn't sure what the boundaries of the blocks would be around the C and D turnouts, which is where all those three operational areas touch each other. How do you figure "at least two" blocks on the mainline? Is it just because of its length, or because of the location or all the turnouts, or what...?
I'm going to pick up some of the more recent wiring books as soon as I can, but I think I've understood the basics of what my options are. The chief thing I still don't get is, when all those big wires come back from their respective blocks to the control panel, and each one gets a DPDT switch, and I have, say, a minimum of 4 or 5 DPDT switches and possibly as many as maybe 15 -- how do so many switches get wired into just one or two power packs? Ed only said this:
7j43kOnce those teeny wires get down below, you can connect them to the bigger wires that travel farther. In this case, to the center two terminals on your DPDT center off switches. Those wires feed power to each and every block you are creating.
...and he tantalizingly refused to give more clues until I school myself with the books. If you all maintain Ed's wall o' silence, very well. I'll go read. But I'm hoping one of you just can't contain yourself and will explain this last hole in my understanding of how the blocks are wired to the power source.
I'm going to draw a picture of what I think this looks like. Might take a day.
Thanks
LastspikemikeOr you can run both sides of your wiring through DPDT switches instead of only the Block control wires through SPDT switches. But why?
Hi Mike. As to the why, I'm not sure why, except that I think I can picture the DPDT method and intuitively "get" what's happening there, while I haven't yet fully grok'd what you've outlined. I'm sure it's all there, but I would need to sit down with a drawing pad and read your replies again and draw a schematic of what you've described. Then it might make more sense, since I learn best visually.
But regardless, it sounded like you just told me I could connect more than one pair of wires to the DC terminals on my power pack. I just wanted to confirm that's what you're saying, because that's a surprise. I thought you were going to say that each set of bus wires coming back from the blocks has to have its own power pack. But if I understood correctly, even Mel is using just two power packs. I still don't get it, unless it's the comment you made about all the block switches being strung along one wire.
Wo, I think a light bulb just went on in my head. Maybe.
For those still waiting for Amazon to deliver the books they ordered two days ago, here's a picture of a "layout" with 4 blocks, wired in the traditional way:
Here's a picture of a layout wired with common rail:
Note that it is Extremely Dumb to just run only that one common wire to your layout. When the locomotive is on the other side of the layout from the common wire connection, it will be using a goodly length of rail in its circuit. And, of course, using a number of rail joiners to conduct the electricity. Or not.
7j43khere's a picture of a "layout" with 4 blocks
Note that for BOTH styles, there is a handedness to the track. You'll see if you got it right when you first try running trains.
And be SURE to get the center-off style. That's how you can store your engines.
Hi there. I said three blocks for the mainline thinking you might have two locos on the mainline, and one switcher that goes on the mainline for switching operations. When switching, the other locos need a place to "rest" while the switcher is active.
As for the power sources, using two powerpacks makes it a bit more complicated if you also want DCC. One powerpack is easy because you can just switch between the DC power source and the DCC system. Two powerpacks makes it much more complicated and risky. Frankly, your layout is not that large, not sure two power packs are that useful.
Simon's point is interesting. While tradition* for DC block wiring uses two power packs, there's no need IF you will only run one loco at a time. Then all you need are essentially kill switches, and the blocks to "kill".
Staying with the common rail theme, then all you need for each block is an SPST (plain on/off switch).
The two power pack approach becomes necessary if you want to run two trains at once. And if it's only you, maybe you just don't want to. It's hard enough to manage one train.
*I think the tradition of two cabs is because it's not much harder to wire for two than for one. So two is sorta "free". Three or more gets into some fancier switching. In my old club, we had eight cabs, and the dispatch panel was covered with rotary cab switches. They are NOT a delight.
The wiring of eight cabs is not all that difficult. You still only need two wires out to each block, though there WERE a lot of blocks.
But DCC is INFINITELY better than what we had!
Ed, I ran my previous 4X6 layout for years that way. You can run two locos on one powerpack, but the controls are obviously more primitive. But I quickly found out that running two locos on a small mainline is not that enjoyable, unless you run your locos very slowly. It was OK with my slow geared steam - i would run one lumber train and one mining train pulled by Shays and Heislers. Nice and slow, on the same line. It was neat. In fact, now that I have a larger layout, I don't run my geared steam as much as I did with my small pike. I should learn to be more patient.
Anyway, I digress. My point in my precious message was mostly about mixing the traditional common-rail, two power pack wiring to a combined DC-DCC wiring. I can't see how you can go from DC to DCC at the flick of a single switch with that arrangement, at least between the power sources and the track. I could imagine a major DPDT switch that turns off the 110 volt connections, turning on either the DCC system OR the DC Powerpacks, with a middle OFF point to ease the transition. But the current may reach the other systems and harm them if no other switches are involved... Perhaps someone like you or Mel can figure out a way to do it otherwhise.