You missed the “isolated power packs” in my post.Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
Lastspikemike...The problem with common rail when using nickel silver is that it is a poor conductor, relatively....
ATLANTIC CENTRALYou guys can talk all you want about buss wires and feeder drops. I have blocks 60' long with one feeder, no voltage drop problems, all rail joints in each block soldered.
Here's the power feed to my layout, also with all joiners soldered...
Not counting staging yards, double-tracked areas or industrial spurs, there's approximately 250' of mainline.
While I run only one train at a time, in most cases it likely has more than one locomotive, due to the many grades, most at about 2.8% and most of them on curves, too.
Yeah, the trains slow when going uphill - heavy grades and lots of curves have that effect. When they reach level ground again, speeds return to normal, regardless of how close or far they are from those two wires.
My wiring is simple because my operational needs are simple...I guess I'm pretty simple, too, as I'm still havin' fun.
Wayne
Kevin, clearly what you do with power routing is a simple version of what I do.
My first layout was wired as you describe.
Sheldon
The OP had a fairly simple question about DC wiring. I believe DPDT CO switches for each block, and gapping both rails will be the most straightforward and easy to implement solution to his situation.
That said...
My approach to wiring is to have the toggle switches on the control panel operate the turnouts, and all block selection functions controlled by the auxiliary contacts on the turnout motors. I started building like this on my first HO scale STRATTON AND GILLETTE layout, and have stuck with it.
I control turnouts, the turnouts route the electricity. I will have no cab selection switches, and only a few blocks will require On/Off switches.
Common rail can create problems, and it can make troubleshooting more difficult.
I have heard that it is easier to convert DC layouts to DCC if you do not use common rail, but I have no experience with this.
I prefer to only talk about subjects where I actually have hands-on experience and solid understanding. I also freely share pictures, good and bad, of what I have done.
That way, people know I am not just repeating things I have read and do not actually understand.
I know DC wiring, layout building, and a little about brass steamers. I am learning a lot about other subjects, and I would like it if only correct information was posted.
-Kevin
Living the dream.
Even with only one power pack, I always used direct home wiring, not common rail. Just never liked the idea. And absent a reversing section, the Atlas plans almost all showed one feeder to the common rail for the entire layout (since Atlas turnouts are not power routing). With sectional track, that never worked well for me, feeding both sides in each block was much more reliable, not using unsoldered rail joiners as the only path for electricity. Keep in mind, I was doing this at a fairly young age, and did not have proper tools to solder rail if I wanted to. Layouts as an adult use flex track for fewer joints and I do solder, at least some of them, and no loose rail joiner is used as a power path.
I mainly was just following what my Dad did - I understood what the Atlas books showed, but I never followed their exact wiring on the couple of layouts I built from their plan books. My Dad always gapped both rails and ran two wires back to the block control. It all started when I was about 5, came down one Saturday morning to find he finished the track all the way around, so I tried running a train - it got halfway around and died. I crawled around trying to figure out wire, found the insulated joiners and the terminal track. Got some wire, screwed it on, and had the train running by the time he got home from work. No need to wonder how as a freshman in high school I already knew I wanted to get a degree in electrical engineering.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Lastspikemike What we did is equivalent to common rail, works and is completely DCC ready, in fact can be switched back and forth between DCC and DC. We have modern MRC powerpack/controllers. One twin and one single for our three cab layout. Works great for us. Easy to describe, no diagrams required. Easy to wire and easy to change the wiring.
What we did is equivalent to common rail, works and is completely DCC ready, in fact can be switched back and forth between DCC and DC. We have modern MRC powerpack/controllers. One twin and one single for our three cab layout.
Works great for us. Easy to describe, no diagrams required. Easy to wire and easy to change the wiring.
Mike, I get it, that works fine, clearly it suits your needs. I'm big on control systems fitting the users needs.
For me wireless throttles are a must have. CTC and signaling are a must have.
Sound and the other complicatons of DCC are not something I want.
My system is fully intergated, Cab assignment, CTC, signaling, turnout control, and collision avoidance are all built in. It is this intergrated approach that justifies the complexity. Each feature provides information and actions that make the next feature easier to impliment.
Here I will try to explain how DC Cab Control can be made much more user friendly.
The example is from the layout of a friend of mine, now departed, who had me wire his layout.
It is a single track railroad with passing sidings, here is a control panel from a typical town. The layout uses four Aristo wireless throttles.
In the photo you will see a map of the trackage for that "town". The white marks indicate block boundries.
Only the east and west single track sections are directly connected to a throttle using the lighted pushbuttons.
All other trackage is energized or de-energized based on turnout position and throttle selection for the east and west tracks.
Try to keep up.
If both turnouts are assigned to same throttle, and both turnouts are set to the main, that throttle will control that route all the way thru and the passing track and all secondary trackage will be dead, meaning locos or trains can be parked on those tracks.
If the east block is assigned to throttle A, and the west block assinged to throttle B, turnout position will determine track power at the passing siding.
If both turnouts are still set to the main, the passing section of the main will be dead and prevent trains from running into a block they don't control.
But if the turnout on one end is set to the main, and the other end set to siding, the two operators approaching the siding will be able to pull into their respective track.
After one or both stop and the turnout is thrown, and the oposing throttle reassigned, the train trapped in the siding will have no power and the other train will be able to proceed.
And so on, as you feed your route, from one end or both, you can use the trackage of the route you set. If you have no route, the track under you is is dead. If you put a loco in a dead end siding and throw the turnout against it, it has no power.
The pushbuttons in the upper left, power the next block in the next town so you can have walk around operation without running ahead or doubling back.
Only rule - don't take a block that someone else is using, wait for them to turn it off, then you know you can have it.
This layout was run for years by a group of guys who mostly use DCC at home, they all found it easy to use and liked it.
I don't know if I have enough time and energy for this conversation, but here goes.
There is nothing "wrong" with common rail wiring, but there are advantages to not using it.
To explain those advantages, it would be best to have drawings, drawings I do not have at my finger tips ready to post, and that require more time and effort than I have available right now.
Some dual power packs over the years will not work with common rail.
I use pushbuttons, not toggle switches to connect throttles to blocks. When you select a new throttle, the previous one is released. This allows redundant controls at both ends of every block and duplicate controls on the CTC panel, allowing CTC control or walk around tower control.
Much better than rotary switches if you want more than two throttles.
Now, I hope everyone will be able to follow this. If you do not use common rail, and therefor you switch both wires, and each throttle has its own power supply transformer, you can prevent trains from crossing gaps into a block assigned to a different throttle by simply staggering the rail gaps by a length similar to your longest loco. If the two blocks are not assigned to ther same throttle, and a loco crosses the gap closest to it, there will be no current path to either throttle, the loco will stop.
Every interlocking on my my layout is such a section, and only gets power when both blocks on either side of a route are assigned to the same throttle.
This also means that large complex interlockings do not need to be blocks at all. They are called X-sections. They become part of the two blocks in the selected route or routes thru the interlocking.
This is done with contacts on the same relays that control the turnouts from both the CTC panel and the local tower panel.
This eliminates about half the blocks the average DC layout will require.
You guys can talk all you want about buss wires and feeder drops. I have blocks 60' long with one feeder, no voltage drop problems, all rail joints in each block soldered.
There have been lots of good DC Cab Control systems built over the years, and lots of bad ones.
The good ones are easy to use and understand, and often don't use all that many "toggles", if any.
One club I once belonged to used control panels that were a map of the layout. Each block contained an 1/8" phone jack, you "pluged in" to assign a given block to your throttle. It worked fine. No toggles.
Reverse loops can also be handled a number of different ways. My new layout only has one, not really a loop, but a wye, and it is "semi automatic". You never reverse the "main" like other reverse loop wiring, you simply need to know if you are leaving the wye to go west, or to go east, and set your loco direction accordingly.
On my layout, from all viewing positions, trains moving left to right are eastbound, trains moving right to left are westbound. The wireless throttles have a left direction button, and a right direction button.......
RR_MelGreg is correct. It’s not possible to operate two locomotives in opposite directions on a DC layout without the possibility of shorting whether it is common rail or both rails switched.
confusing.
it's certainly possible to operate in both directions using common rail. Atlas sells products to do this that i'm sure thousands have used.
there is the possibility of a short similar to when bridging the gaps at a reversing section. cabs need to protect against this
i don't see how excessive voltage can occur across a passenger car lighting circuit, for example, before a short occurs. if the right side wheels are on the common rail and the left side wheel are connected together, won't there be a short when different wheels on the left side straddle the the gap between blocks? won't one wheel possibly see 12V and the other -12V.
How to wire a layout for two-train operation
greg - Philadelphia & Reading / Reading
Greg is correct. It’s not possible to operate two locomotives in opposite directions on a DC layout without the possibility of shorting whether it is common rail or both rails switched.As long as all traffic is operating in the same direction it will work either common rail or both switched.All of my layouts since 1951 have been both rails switched and I operate in both directions simultaneously but I have to be careful to make sure the advanced blocks are the correct polarity, a mistake could be disastrous. That is a major advantage using DCC, no polarity problems.
Sorry for the error. Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
RR_MelYour post says DC and if you want to run separate locomotives in different blocks using DC in different directions you can not use common rail, you must switch both rails.
not true
I built my layout using common rail, and it meets all of my needs, as I have no desire to have more than one train moving at any time, nor to have multiple operators.Wherever I have double track (only through every town on the layout), it's controlled by DP/DT/CO switches, allowing one train to pass another one, which is stationary (in either direction). This suits my choice of sequential operations, where each particular train moves only when I decide that it should move. My version of the KISS method.
I have also never used common rail. Isolating both rails makes troubleshooting easier.
My planned layout only has one "block" that can be controlled by one of two cabs. The cab that controls this section will be set automatically when a turnout is thrown to connect this block to the mainline. Then it will switch to the mainline cab.
Planning a layout for one man operation lets you do all kinds of things in a more simple manner.
Your post says DC and if you want to run separate locomotives in different blocks using DC in different directions you can not use common rail, you must switch both rails.
Using isolated power packs would work but I wouldn't recomend common rail!!!! An accident looking for a place to happen.
If the top rail in the picture below was common there is a potential high voltage between the two blocks. An iluminated passenger car with trucks in both blocks could have higher voltage applied to the lighting.
Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
ATLANTIC CENTRAL gregc RR_Mel You would need to use a DPDT switch to each block. a DPDT? maybe for a reversing section where polarity is reversed How to wire a layout for two-train operation Sheldon
gregc RR_Mel You would need to use a DPDT switch to each block. a DPDT? maybe for a reversing section where polarity is reversed How to wire a layout for two-train operation
RR_Mel You would need to use a DPDT switch to each block.
a DPDT? maybe for a reversing section where polarity is reversed
I believe the popular Atlas block control components (and thus the Atlas wiring books) assume common rail. Westcott's old wiring book shows both.
Dave Nelson
I have never used common rail in my 69 year model railroad career and don’t recommend it. I have always used DPDT switching both rails. My current and last layout has 24 blocks each with a DPDT Center Off switch. I run dual mode, DC OR DCC.
This is my control panel showing the DPDT CO block switches. It's hard to tell the colors but the blue toggles are block switches, the red are turnout control, white are lighting.
This is a CAD drawing of my layout.
Are you suggesting SPDT switches and common rail? I've been using DC cab control for 53 years and do not recommend common rail wiring. Maybe later when I am not working I can take the time to explain why.
I edited my post, I forgot to put in Center Off. He will need to duplicate the “Block Switch” for each Block.Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
RR_MelYou would need to use a DPDT switch to each block.
Right on KevinStix is correct. You would need to use a DPDT Center Off switch to each block. Parallel the Cab wires for each block.Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
Bing MattsonI'm thinking a section of trsck that can be powered by two cabs, one at a time
Normally in DC, the entire layout would be divided into blocks, and each block would be wired with a DPDT switch so it could be operated by either DC controller. So the entire layout could be run from controller A or controller B, or some blocks by A and some by B. You wouldn't just have like one 'section' that would be wired to a DPDT to transition between a block only powered by A and one only powered by B.
Some large layouts have been set up using a rotary switches instead of DPDT toggles, to allow power to be routed from 3 or 4 different controllers.
Mel's drawing is correct.
The switch you want is a "Double Pole Double Throw Center Off", often abbreviated like DPDT CO.
The center off position allows you to disconnect power to that block without a seperate On/Off switch.
I hope this is what your looking for.Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
Can anyone put up a drawing of controlling power between blocks? So I can run a train into a block, shut it down and have a differant cab take over and restore power to that block without powering up the other block, I'm thinking a section of trsck that can be powered by two cabs, one at a time, Thanks if you can help.