First off I love reading the forums and seeing all the cool pics of the layouts you all have created. I hope to some day get to the point a lot of you are at…REALLY neat stuff!
I am in HO scale.
I would like to have a long run of two parallel tracks. I will not have a lot of fancy stock (just basic passenger cars and rolling stock). I would like to know how far apart the two track should be (on center) to allow trains to move freely, while also being able to use typical double track bridges that you can buy from various companies? (I really don’t want to build custom bridges…modify a little yes but not scratch built)
I am going to run DCC. Little confused about the bus wire. The Command center supplies power to the bus. Then you run feeder from the bus to the rail. My question is does the Bus wire loop back onto itelf at the end? (Does the starting point of the bus get wired to the ending part of the bus or can I just stop the bus with my last feeder to the track?)
I really hope these basic questions make sense for all of you pro’s! And I really ADMIRE what you are able to create and hope to get there someday!
To answer your first question. You can have the roadbed of the two tracks up against each other and that should work. Others will have other ideas.
On your second question, you should not need to loop it back to it self. I don’t have a layout, but I did see a guy’s personal layout where he used the end of the buss wire and soldered his last feeder to and then to the track.
First off. How large is your layout going to be? These two pics might give you some ideas of where to start. The first pic shows how I did mine. My buss lines run out like fingers down this 18’ bench. They are only as long as they need to be. Right now there are four fingers. One for each side of the two loops. My farthest away feeders are joined to the ends of the four buss wires. I have feeders every six feet. If there is a piece of track without a feeder attached to it I make sure that track is soldered to one that is. Though most of my track is soldered to the next as I like redundancy.
I will ad more “fingers” as I ad some yards. The plywood holding the power distribution panel is hinged so it flips up and out of the way until access is needed. Good luck, ask lots of question and post photos of your progress.
The typical separation of two parallel tracks (centerline to centerline) is 2 inches. Bridge models usually have the same track separation. Of course, if two single bridges are used, they will need to be further than 2 inches apart. Still, usually more than 2 inches of clearance is needed on curves so trains on the different tracks won’t sideswipe. The separation depends on the track radius, car length, and nature of the locomotives. See this site for recommendations:
Mark’s got it right! I will add that crossovers (double and single) also use a 2" spacing (IIRC). I use 2-1/2" for most of my double track mains on the straights and 3" (33" and 36" radius) on curves. I converge the tracks for a pair of double crossovers and use parallel single track bridges. Never had a problem even with long cars. Of course, 80 footers don’t look great on 33" curves but they do run without sideswiping.
Generally 2 inches. If you have long cars it might be good to expand it out to 2 1/4" or even 2 1/2" on the curves. The tighter the curve the further apart they need to be.
Either. It really depends on how big the “loop” is. On something like a 4x8 layout a loop is a natural. Around the room layouts where a loop is longer than 25’ it gets questionable. Usually if one gets to that size one starts making multiple blocks so there is no natural loop.
Yep. If only because of the long straightaways on the 18ft. You could get away with 2 blocks, I’d go three myself, divided up relatively evenly. That wy your trains don’t start to dog at the other end of the layout.
2 inch apart is fine for running, but if you are working on the trains (big hand from the sky) and changing cars it would be a tight fit if both lines have trains on them. Back of my bench where the trains just run, I use 2.5 inch’s, just worked out that way. On the front where I fiddle with the cars, rather passing spur or yard I use 3.5 inch. Just makes it a Little easier not to knock another car off.
On turns, I use 3 inches, I run big steam with tighter turns than I would like to. 26 inch is the biggest, and still have one 18 inch left. It is going to go!
Blocking, hum I might get a rash on this one. The only reason I see to block DCC is if you don’t want all the trains to stop if there is a short (Derailment) during Op’s with other people running. You will need extra equipment to do this, around $40.00 or so. If you are going to run by your self most of the time, I see no reason to do this. My bench is 19 X 13 with apx 300 plus feet of track with 3 main lines, 49 turnouts and 4 interchanges (one line goes to another line) and mine is not blocked.
In there is one pieces of advices I can give you, it would be use heavy gauge of wire for your buss. 18 gauge is the smallest I will use now. Long story but, when I add the new section, used a temp buss of only 24 gauge. Had power and forgot about it. $200.00 in decoders later, Simon 1966 found the problem. If you 5 x 15 is a loop, one buss down the center will feed both sides. I use 18 gauge as feeders, trim out half the wires from the end that gets solder to the rails so it not unsightly. 22 is fine for a feeder if it is under 3 foot long IMHO.
5 foot wide? Is it going to be against a wall? If free standing all the way around you are in good shape! against the wall, time to back up and rethink!
Thanks Ken for your advice. My layout is out away from the wall. What I actually did is put lockable roller/casters on the bottom of some sturdy legs so I can roll it up against the wall when not working on it ,so I can have that dense feel to my layout.
A typical Ho scale double track main should be 2-1’2" from center to center the reason for this is if you intend to run heavy weight passenger cars such as you mentioned in many cases depending on the radius of your curves cars will over hand and hit objects such as switch stands, signs signals etc. even a passing train on the opposing track. An easy way to verify this is measure the center-line distance of any double track bridge such as Walthers, Central Valley or Micro Engineering for example all measure 2-1/2" center to center. Below is a copy of the HO scale chart from the NMRA website along with the notation that applies. When it comes to questions like this not to say that you won’t get the correct information here but the NMRA is the standard by which most everyone follows.
As far as the buss wire looping back to it self I wonder where this originally got started, think about what would happen if you put current to a wire then then touched it to it self? Instant short circuit, you can absolutely dead end your buss wire I fabricated several wire insulators out of wooden dowels that are attached to the bench work in various spots on the layout. the corresponding buss wires terminate at the insulators and are clearly marked as to which zone the are .Ken has some good advice on feeder wires etc. Generally when it doubt always go a step bigger does apply but when it comes to buss wiring you typically get no benefit from overkill like @12 wire which some guys choose use. Our club layout is over 3500sq. ft and we use #14 broken up into zones with not issues what so ever.
Note 8 reads as follows
Construction or operation of equipment on curves sharper than those listed for its class are neither prohibited nor recommended.
Mark’s got it right! I will add that crossovers (double and single) also use a 2" spacing (IIRC). I use 2-1/2" for most of my double track mains on the straights and 3" (33" and 36" radius) on curves. I converge the tracks for a pair of double crossovers and use parallel single track bridges. Never had a problem even with long cars. Of course, 80 footers don’t look great on 33" curves but they do run without sideswiping.