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HOW do you block a DC layout?

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  • Member since
    November 2011
  • 343 posts
Posted by SUX V R40 Rider on Wednesday, November 28, 2012 9:17 PM

The Athearn GP50 runs great on the layout. It is cold outside and after I  unpacked it I let it warm up to room temperature. Then I ran it at various speeds going forward for about 20 min. or so then at various speeds in reverse for about 20 min. around the oval. After that I replaced the metal rail joiners with insulated ones on both rails. Remember I am running Bachmann EZ Track, not continuous track where only one side has to be gapped. One one side of the insulated joiners is the turnout and on the other is the new 9" terminal rerailer. The new rerailer is connected to power pack B.

I then tested both locomotives, separately,  with both power packs set to the same direction and it works great. I tested  it in both directions.

So for right now the one and only siding I have is operated by power pack B and the remote turnout and mainline is operated by power pack A.

But I already see a minor issue that could turn into a source of frustration as I build more sidings into the yard. That is when I need to spot cars on the mainline with the GP loco. for the SD loco. to haul I think I am going to have to literally and pick up and remove the SD loco. off of the track by hand. Or do the same with the GP loco.

 I already know I won't have a problem with spotting cars on the various sidings within the yard while the SD hauling its load around the mainline because it is separated or blocked from one another with the insulated rail joiners. But once the GP loco. starts to spot cars on and off the mainline, if the SD loco. is sitting there it is going to be an issue.

Any ideas on how to stop the SD and have it sit idle until I am finished spotting cars with the GP unit without using DCC?

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  • From: Reading, PA
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Posted by rrinker on Wednesday, November 28, 2012 9:30 PM

 You're going to have to go with the extra switches. If not the Atlas components (I've never been a fan of common rail wiring anyway), you can use DPDT center off toggles. One side goes to pack A, the other side to Pack B, and the center terminals to the track. You will need to isolate some sections - for a yard a better track arrangement would have an extra track off the main as an arrival/departure track, the road loco would pull in there, uncouple, and go elsewhere, then the yard engine could come out and grab the cars and sort them. Each section of track could then be connected to either pack A, pack b, or turned off so a loco sitting there won't move at all.

 Please do pick up a book like Basic Model Railroad Wiring which will explain and diagram all this stuff.

           --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by SUX V R40 Rider on Wednesday, November 28, 2012 10:12 PM

rrinker

 You're going to have to go with the extra switches. If not the Atlas components (I've never been a fan of common rail wiring anyway), you can use DPDT center off toggles. One side goes to pack A, the other side to Pack B, and the center terminals to the track. You will need to isolate some sections - for a yard a better track arrangement would have an extra track off the main as an arrival/departure track, the road loco would pull in there, uncouple, and go elsewhere, then the yard engine could come out and grab the cars and sort them. Each section of track could then be connected to either pack A, pack b, or turned off so a loco sitting there won't move at all.

 Please do pick up a book like Basic Model Railroad Wiring which will explain and diagram all this stuff.

           --Randy

 

Randy, I will pick up the book.

But I think what you're describing is build in a section of track to pull the road loco. into that is connected to a selector switch, such as Atlas, and turn off that section of track, via the selector so it is isolated from the rest of the operational layout until the GP unit is finished spotting cars. Then when finished and the GP loco is back in the yard, turn on the isolated section and run the SD loco. connected to the cars it is hauling around the main oval. With building in this section it will not matter what power pack it is connected to because the selector will have on and off switches.I am thinking I could also isolate a section of the mainline into a selector switch as well that could be powered on and off as needed when the road loco. is spotted on it.

Is this kind of like taking a lamp that has its own power switch and hard wiring it into 2 wall switches, one at opposite ends of a room as well? This way it doesn't matter which wall switch is on, if the power switch on the lanp is not set to on it will not work until it is. BTW I have actually wired a floor lamp to do this.

Am I far off from what you describe?

  • Member since
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  • From: Reading, PA
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Posted by rrinker on Wednesday, November 28, 2012 10:29 PM

 What you do NOT want is a simple on.off switch from each power pack going to the same section of track. This will work - up until you forget and turn both on at the same time. If it doesn't matter that the isolated section is always controlled byt he same power pack when turned on, you can use somethign like the Atlas Connector which is simply 3 ganged on/off switches - the power pack connects tot he side, and across the top are pairs of connections that go to each track section. Like the Selector shown for dual cab control, you can chain multiple Connectors together if you need more than 3 sections.

 But this won't be enough if you really want to have the two power packs and control multipel trains. It simply cannot be done other than with either the Selector feeding eacha nd every isoalted section, or DPDT toggles to avoid the common rail wiring. If you use the Connector, and have tracks 1-3 controlled by Pakc A< and tracks 4-6 controlled by Pack B, sooner or later you will need to move a train on track 2 from pack B, and that won;t be possible with a setup like that. Witht he Selector type of setup, you cna control any section of track from either pack, at any time.

By now DCC ought to be looking awfuly simple. No insulated joiners, just have a few terminal sections all wired in parallel (2 wires alone won;t cut it, rail joiners stink for long term electrical connections, so a few extra feeders will make everything more reliable). Then you can run any train anywhere, stop anywhere, even run one up to the tail end of the stopped train and pluck cars off it for switching.

               --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by SUX V R40 Rider on Wednesday, November 28, 2012 11:00 PM

Randy, I wasn't thinking of a simple on and off switch going from each power pack going to the same section of track.

I was thinking of:

  1. Using the first siding as the pull off for the road unit, with or without cars attached, connected to power pack A along with the mainline also connected to power pack A at the same time. the difference is the pull off will be isolated with wiring going to a separate on/off switch. When necessary I pull the road loco. into the pull off and turn its switch to off, but the mainline still has power to it. Only the pull off siding is turned off.
  2. All of the other sidings are operated by power pack B. These make up the yard. It is within the yard where the GP loco. is primarily operated until it needs to enter the mainline to spot cars to be connected to the road loco.
  3. After the GP unit is finished spotting cars on the mainline it retires back to the yard. The switch that has the pull off siding turned off is set to on and the road unit rolls onto the mainline, connects to the cars and off it goes around the mainline.
  4. While the road unit is hauling around the mainline I can still operate the yard loco. to spot cars where needed on the sidings, as long as I do not travel over the turnout that is blocked using the insulated rail joiners.

What do you think of this?

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Posted by SUX V R40 Rider on Thursday, November 29, 2012 12:30 PM
If i use the correct toggle or selector switch to isolate a pull off siding to spot the road loco. on and set the switch to off while the yard unit is sporting cars on the mainline with the mainline operated by power pack A will this work as i described in my previous comment?
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Posted by maxman on Thursday, November 29, 2012 2:41 PM

There have been some good suggestions, along with a couple good sketches.  What you really need is to get one of the wiring books.

If you don't want to get a book, I suggest the following link to an NMRA article called Basic Track Plan Expanded and how to wire it: http://www.nmra.org/beginner/extended.html.  It shows a layout that sounds similar to what you seem to have, as there is a loop with a small yard attached.  It is wired for dual cab control, which is what you would have with your two transformers.  It uses toggle switches instead of the Atlad products.

The only thing I don't like about it is that it is common rail, hence the single pole/double throw switches.  If it were me, I'd use double pole/double throw toggles, where both wires from the transformers go to the toggle switches, and then go to the rails.  However, this is a matter of preference.

If you study the diagram, you'll see that either engine can be parked any place if you don't want it to be running.  Or you can run them independently of each other so long as you don't cross from one block boundary into a block where the other engine is operating.

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  • From: Reading, PA
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Posted by rrinker on Thursday, November 29, 2012 8:15 PM

 Yes, it should work as you describe. That's why you use the DPDT center off toggles - so a given section of track can be connected to pack 1, pack b, or off completely. So you can park a loco by setting the switch for that track to off, set the switch for the main to pack a, and run the train with A. Once clear of the yard lead, you cna set the switch for the siding and yard to B, and run that loco with pack B.

 Excact placement of isulated joiners and feeds is going to depend on the actual track layout. Do you have a plan of what you're building? Hand drawn and scanned, computer drawn, even a phot showing the whole thing, would be helpful.

            --Randy

          


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by SUX V R40 Rider on Thursday, November 29, 2012 11:33 PM

I'll post some photos soon. Right now I am working n drilling holes in the wood deck large enough to feed the square shaped connectors through that plug into the EZ track terminal rerailers and the remote for the turnout. The existing wiring I am using is at the point of needing to run it under the table, instead of across the top of the island and under the track bed. All of the holes are drilled. I just need to clean up the saw dust, put the track back together and add the trains to it.

I am not worried about how many holes I have drilled and the fact that they are so big. Eventually the deck will be covered with the 2" pink or blue insulating board. This will have holes drilled into it that will line up with the holes in the wood deck. Covering the insulating board will be a scenery mat that will be the appropriate color for what I am running at the time. This mat will have slits cut in it to allow the square connectors to feed through to connect to the rerailers and remote for the turnout. What little wiring is exposed will be hidden by something in the scenery.

No I am not planning on fastening down the EZ track because it has to be able to be easily taken apart to be changed or taken apart for transport.

As the switching becomes more complex I have figured out near the corner of the layout just on the outside of a radius corner of the oval will be too small to leave the power packs sitting, especially when I add more switches. For now I am going to use an old desk to sit the power packs on along with switches as they are added. I will mount the switches and the one power pack to a board and clamp it to the desk. this will work until I can build a control table with folding table legs to sit at the end of the layout. All of the wiring, no matter where it is connected to on the layout will end up connecting to something on the control table. I will build this as I need it, which will be as the amount of switching becomes more complex.

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Posted by passenger1955 on Saturday, July 30, 2016 1:23 PM

I was just looking at this old diagram you posted (thank you). Can you please help me understand something about the common rail? When someone flips the direction switch on Power Pack Cab A (so that block can run in reverse) my expectation is that the polarity would switch, and the terminal connected to the common rail would switch from (for example) positive to negative, which might conflict with the polarity in Power Pack Cab B. Obviously it doesn't (or you wouldn't have posted this diagram). Can you please help me understand why having the power packs switch polarity in a common rail setup isn't a problem?  Thanks.

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Posted by rrinker on Saturday, July 30, 2016 1:56 PM

It does change exactly as you think, but the only 'conflict' is between the non-common wires from each power pack. Between the common side and any one of the power packs, you are simply changing the polarity and reversing the train. You need a complete circuit for any current to flow - hooking the _ of one power pack to the - of the other, as happens in common rail if one is set to forward and one is set too reverse, does not make any current flow between the two.

 Let's say they are both on full throttle and htey put out 12 volts. If the common side os - on both packs, thus the free wire from each pack is the + side, you would measure 0 volts between the free wires, but between either free wire and the common wire you would get 12V. If you now flip the direction switch on just one of the power packs, you now have a - on one free wire and a + on the other. If you measure across the two free wires, you will now have 24 volts - this is just like 2 batteries in series. But between the common and any one of the free wires, it will still be 12 volts.

 The only possible place you could have a problem is if you run a train across the gap where one side is controlled by one pack and the other side is the other pack, and they are set for opposite direction. The voltage across the gap is the 24 volts in this situation and if a loco coasts past the gap you could have a 24V short circuit going through the wire that connects the front pickup to the rear pickup.

                     --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by jjdamnit on Saturday, July 30, 2016 10:32 PM

Hello all,

SUX V R40 Rider
Yes, DCC is out of the question right now. Mainly because of the expense.

I would seriously consider DCC.

After purchasing the controllers and switches; either Single Pole Double Throw (SPDT) or Atlas Controllers, and the accompanying footage of wire, you will find that the most basic of DCC systems will serve you better. And cheaper.

As Cody Grivno says, "Don't ask me how I know this, I just know this."

Bachmann makes an extremely simple and inexpensive system know as EZ-Command. (Add snarky comments from other DCC users here.) Ignore the MSRP from Bachmann and look at eBay for deals on this system.

On a 4'x8' simple pike you can get away with one set of feeder wires to achieve your goals of two- or multi- cab operation.

That means, rather than buying and installing literally tens-of feet of wire you can cut that down to a few feet of wire from the controller to the track. Which, is included in the EZ-Command set.

The only other expense is wiring your existing DC locomotives with DCC decoders.

If you have the knowledge and tools to wire a DC pike, installing simple DCC decoders in your existing motive power can be easily done.

However, if you insist on wiring your pike for dual-cab DC operation then I would consider purchasing the Atlas book; The Complete Atlas Wiring Book. This publication not only explains multi-cab control but also is a great primer for turnouts, reverse loops, etc.

Hope this helps. 

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

  • Member since
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  • From: Western, MA
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Posted by richg1998 on Sunday, July 31, 2016 12:31 PM

A resurrected thread. Got to love it.

Back in the early 1980's our club wired a layout using the common rail approach with fourteen blocks and one reverse loop. Wow, time's fun when you are having flies.

A single DPDT switch for the reverse loop and a bunch of SPST switches for blocks. Used the wiring book from Kalmbach I believe.

We used #24 telephone wire because the club president worked for telephone company.

Four throttle capability. We needed a dispatcher at the control panel. “Who's got my loco” was a common question when the dispatcher was gabbing.

Most times, one loco unless someone had a couple locos that matched well under DC.

With DCC, all blocks turned on and reverse switched ignored.

DC ampmeter and voltmeters no longer worked.

Made a DIY DCC ampmeter and used a cheap digital voltmeter for track voltage. NCE Power Pro shows about 13.6 VAC as I last recall.

A large red LED meter shows DCC current and can be easily seen anywhere in the room.

Had to finally install #14 wire for feeding the layout.

Some like the EZ Command for simplicity as compared to DC for only a couple locos and one DC only loco can be used but that is another issue. Some just do not count all the rivets.

Downside, no modification of CV's and last I knew, you cannot do a decoder reset. You can program the loco number but this system is old school but cheap enough on ebay.

You can control nine sounds on sound equipped locos.

Some still use the system as I have seen in the Bachmann forums.

I use the NCE Power Cab which does not run DC locos. I switch systems but that is rare anymore.

Rich

If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.

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Posted by JimKay on Thursday, August 4, 2016 11:05 PM

Hello: I am from the old school I run DC. I usually block 6 to 8 real feet on each main line. On my present layout I am using 3 power supplys. How ever long your blocks are, you have to insulate the front and the rear of the block. I use plastic rail joiners. Than if you are on main line 1 you have to connect a power supply to that block. Now you have to break the power connection with a switch, your choice. When you want to switch from  main 1 to main 2, you leave the turnout stright thru but you must insulate the switch where it goes into main 2 again useing plastic rail joiners. I am running 25 engins and 500 rolling stock including passenger trains. My main line 1 is 100 real feet long, it has 8 blocks, there is signaling at each block. I have 50 turn outs on the layout including 3 way, double cross overs, and double slip switches. I switch between lines 1,2,3 all of the time. Just remember insulate front and rear of each block, turnouts when switching from 1 to 2 and in my case 2 to 3 and dont forget you must power each block with a switch to control the power. By the way I can run 8 engins on each track at one time. Also when you run your power wires, bring back +/- to a central point. Make sure you dont get the wires mixed up with the other power supply. My e-mail jameskrawiec2@verizon.net

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