New N Gauger: Track Blocking

Discussion in 'FAQs' started by traintraveler, Mar 7, 2007.

  1. traintraveler

    traintraveler New Member


    I'm really trying to understand how one 'blocks' track sections.

    I'm using the Bachmann N EZ track and have been looking for Bachmann terminal joiners
    and connectors. I see Atlas products that seem to do the same thing but thought Bachmann
    would make something for their own track. Maybe not ? If you can use Atlas, do you use
    the "55" or "80" items for terminal joiners, regular joiners and insulated joiners ?.

    I first thought that the Bachmann 'under-the-track' straight pieces and the curved
    rerailer terminals track would be for track blocking but I'm confused now.

    Much thanks.
  2. MasonJar

    MasonJar It's not rocket surgery

    Hi Traveler,

    Welcome to The Gauge.

    I model in HO scale, with flex track, so have no real experience with the roadbed track in N scale... However, track "blocking" is basically creating electrically isolated sections of track. This is done by insulating one or both rails when using DC power, and both rails when using a DCC system. Atlas makes a plastic rialjoiner for this purpose in HO, and I imagine they make one for N. Again, I am sorry I can't answer your specific N scale question.

    Blocking is used in DC primarily for multiple train control, as any two or more locos in the same electrical block will behave the same (speed and direction). With DCC this is not an issue, but the boosters (power supply) are limited in the number of locos they can handle at one time, so blocks are created on layouts that would see a large number of trains operating at once. There are other advantages too, like occupancy detection (locating trains on the rails for centralized control, and signalling, among other things).

    Your second question is about terminal joiners. They are used for feeding power, although many modellers elect to solder feeder wires (18 ga or smaller) directly to the underside or outside of the rails. Don't solder it on the inside, or it may interfere with the wheel flanges.

    Hope that helps.

  3. traintraveler

    traintraveler New Member

    Thanks Andrew,

    If I could get 2 trains running at the same time, that would be great.

    1. Would I need 2 powerpacks to run 2 trains at once ?
    2. If you run 2 w/2 power packs, how do you set it up ?
    Do you need to have totally seperate tracking to do this, so there is
    no shared track areas ?
    3. What I'd really like to do is to have blocked sections of track, like spur lines
    where I have an engine sitting and ready to go. I'd then turn that section on
    and the other section off. Overall I guess the main layout would be available
    for any train use.

    I've been looking at some Atlas suggestions.

    Are there other helpfum booklets on the wiring side ?

    Much thanks
  4. MasonJar

    MasonJar It's not rocket surgery

    Atlas seems to be the most straightforward, although they tend to describe the installation in terms of their specific components. Much of their lineup can be replaced with less expensive (electrical) switches from an electronics store - on/off, DPDT, etc.

    To use the "traditional" DC approach to running trains, you need as many powerpacks as you will have engines operating simultaneously. So if you are going to run only one at a time, you need one powerpack. You will also then need at least one section of track that you can turn on/off for each engine that will be on the layout.

    To run two trains with DC, you need to divide the layout into electrical blocks - at least twice as many as the number of locos you plan to run simultaneously (e.g. to run two trains, you need a minimum of four blocks). The wiring for two simultaneous trains is relatively straightforward, and uses DPDT (on1-off-on2) switches to assign the section of track to the right powerpack. You will need a powerpack for each engine (or one of those MRC ones with two throttles on it, which amounts to the same thing).

    Beyond two, you are much better off going to DCC. It will simplify the wiring, and you can concentrate on running the trains, not flipping electrical switches as the train moves around the layout.

    You can keep the track separate, but it is not necessary. Just take your time with the wiring and you should be ok.

    Even with two trains, DCC is often simpler to do. There are lots of options for decoders in Nscale, as well as ready to run (if you haven't already got enough locos).

    There are lots of internet sources for basic information. One good place to start is - beginner page. And to get an idea of DCC, try or a simpler explanation at

  5. traintraveler

    traintraveler New Member

    OK, Seems that I can proceed better now.

    Do you have a suggestion on a good (& adequately powefull) power pack ?
    (Should I consider a dual unit in case I end up there ?)

    To provide sufficient juice for a layout, should one have several electrical hookups
    spaced out over a layout connecting to the power pack ?

    Since all my engines are non DCC, I just figured I'd have to stay the conventional
    Isn't it expensive or even impossible to convert the engines to DCC ? I can sure see
    now why it's poplular.

  6. MasonJar

    MasonJar It's not rocket surgery

    Any of the packs made by MRC (Model Rectifier) are good - sort of an industry standard. You may be able to find them used for a decent price, but if you have to buy two of them new, you are looking at the cost of a good starter DCC system, or even more than a basic starter.

    If you are thinking it is likely that you will end up with two trains running simultaneously, then you might want to consider the dual pack. It would theoretically be slightly cheaper to do so, but only slightly.

    In terms of the multiple hook ups to the track, what you are describing is a "buss". THat is heavier gauge wire (like 12 or 14 ga) running under rouhgly under the track, with short, finer wire (like 18 - 22 ga) "feeding" the track at regular intervals. This is highly recommended for DCC, and also for DC. With DC, you have to remember where your blocks begin and end in order to avoid wiring two together, so to speak.

    Older engines are not impossible to convert, but some are trickier than others. I would imagine that Nscale is more difficult, considering the space restrictions. But many decoder manufacturers make decoders for Nscale, so you could try. I would suggest you do a bit of research based on your specific engines before you rule it out completely.

    The cost of new DCC equipped engines is coming down all the time, and is currently at the point where some engines are no more expensive with a decoder (and might be hard to get without...!). Decoders are also getting cheaper, but as with anything, it is possible to spend as much as you'd care to on decoders - from less than US$20 to $100 or more, depending on sound, functions, etc.

  7. traintraveler

    traintraveler New Member

    Thanks again.

    I'm going to get the Atlas book for electrical wiring to better understand some
    of the electrical considerations.
    I've looked at the Atlas selectors and connectors which show some hookup
    arrangements on its package backside. The selector setup clearly shows 2
    power packs, the track blocking, the selector and how it's wired.
    But what still confuses me big time is just how does one powerpack end up
    controlling a specific engine when the wiring seems to merge all together
    when you see the diagram. Gee.
  8. baldwinjl

    baldwinjl Member

    The idea is that at any one time only one power pack (or none, depending on how you have things wired) is connected to any block of track. As you 'drive' around the track, you throw the 'selector' switches to power the next block you are coming to with the power pack you are controlling your train with. It should become clearer when you get the book.
  9. MasonJar

    MasonJar It's not rocket surgery

    It may also become clearer that DCC is a better option, instead of blocked DC operation...! ;)

  10. baldwinjl

    baldwinjl Member

    I was thinking that. I think that for just starting out it is almost the only way to go. If traintraveler wants to discuss it, I'd be happy to say why!

  11. pgandw

    pgandw Active Member

    From what I understand of EZ track, it uses regular rail joiners for the electrical connectins between track sections. If I'm wrong, ignore this paragraph. You can subsititute the plastic rail joiners for the block boundary insulator. Or use no rail joiner and make sure the rails do not quite touch. Most folks glue a small tab of plastic between the rails and file to shape when the glue had dried. Last option, in my mind, would be to cut the rails on the EZ track, and fill the gap with a plastic tab.

    Using Atlas track, cutting the rails away a couple of inches from the rail joint seems to give smoother running track than the plastic rail joiners. The plastic joiners seem to do a poor job of horizontally aligning the rails over the long term.

    Rules for blocking in DC: Setting up blocks for DC control has become a lost art, and is never addressed in magazines any more.

    Rule #1: Every continuous route or loop needs at least 2 blocks per train that will be operating on the circle, oval, or loop simultaneously. This gives one block for the train to occupy, and a second block to advance into. Two trains folowing each other on a simple loop layout need 4 blocks on the loop alone. It there are less, each train must stop until the block in front of it is vacated.

    Rule #2: Both tracks of every passing siding must be separate blocks. This allows one train to be stopped (or moving) on the siding while the other train passes on the main.

    Rule #3: Every dead end spur where you might want to park or operate a locomotive while a train goes by on the main branch of the spur turnout must be a separate block. Power routing turnouts can be used instead of a block toggle for blocks on dead end spurs. The power routing turnout cuts power to the spur when the turnout is thrown for the main.

    Rule #4: Block boundaries at turnouts shall be at the frog end of the turnout, normally close to the clearance point. The clearance point is where a stopped train will not be hit or side-swiped by a train using the other branch of the turnout.

    Rule #5: When possible, blocks shall be at least as long as the longest train. This is a requirement for reversing loops and sections.
    These rules give the maximum operating flexibility using mulitiple trains on a DC layout. Fewer blocks than the rules indicate result in less operating flexibility. The guiding principle is that no 2 trains are ever in the same block.

    yours in DC wiring

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