Is it possible for a layout to be too big? that is, is there enough power to function everything that far away from the electrical source? just how far can a train be operated, hundreds of feet? thousands? Some very large club layouts must have hundreds and hundreds of feet of track, is there only one source of power or is there additional power somewhere in the system? could you essentially have a piece of track 2500 feet long and the train still run effectivley?
Our club has 10 blocks with separate power supplies. But it is not because of distance it is because of the power consumption of mass quantities of locomotives. We also wanted to isolate any short circuits to one part of the layout.
There has to be a theorticial limit that could be calculated by the resistance of the track. A long time ago I had an O-gauge locomotive that slowed down about 50 feet away from the power supply. It was steel track so I added a second feed from the power supply through some bell wire (copper) to the other end of the track.
In theory yes, a layout can be to big for one power supply even if it is only running one locomotive. Every inch of wire or track has a tine electrical resistance. Every connector has a little bit more resistance. Ultimately these small resistances add up to more than the power supply can provide. Back in the 1920’s when my prototype was running electrics they built small powerhouses roughly every 10 miles. Large club layouts with DCC can put boosters intermittently along the track but for most of us we run out of room before the resistance in the wiring and track eats up our power. Even the clubs that us boosters do so because of the number of locomotives running not because of the resistance in the track.
No, you can’t have super long wire.
Specifically, the wire becomes a resistor (just like your locomotive).
The resistance in a wire (neglecting temperature effects) is equal to a constant specific to the conductor, multiplied by the length of the wire, divided by the cross sectional area of the wire.
In the case of a layout, the track becomes the “wire”.
In short, you increase the resistance as you increase the length of the wire. You decrease the resistance as you decrease the diameter of the wire.
Hey, you could always use like golden gate bridge support cables for wire, then your resistance wouldn’t drop, and you could have a pretty good sized HO layout![:D]
In theory, there is no limit to how big a layout can be (provided it’s not bigger than the earth, that is. [:)]). You can distribute power effectively to make up for any kind of voltage drop if you know what you are doing.
For example, at our club, our layout will be 6,300 sq. ft. We don’t expect to have any problems as long as we have enough boosters (we’re running DCC). Currently, we have approx. 1/3rd of the layout operating, and we’re using five 8 amp boosters spread out around the layout. Each booster powers a “zone” or block that can be several scale miles long (that’s 60’ per mile in HO scale).
Now, as far as one track and one power supply, then yes, there is a practical limit to how long you can run the current before the voltage runs out due to resistance of the transmission medium.
Paul A. Cutler III
Weather Or No Go New Haven
If you are going to build a monster layout, you should have a bus wire to carry the current rather than rely on the track to do so. This is a must for DCC layouts since track is a poor conductor. Yous should also do this for DC if you have a very large layout. Feeder wires should be run from the bus to the track at least every six feet for DCC.
Excellent answers, thanks, even I can understand the electrical concepts here, not that I am planning a 6300 foot layout, although, hmmmmmmm.
OK, it’s just a theoretical question, but humor me, OK?
If you are running DCC with Boosters, you still need to get the basic DCC signal to the boosters, besides getting booster power out to the locomotives through the bus wires and track. How far from the main base station can you put a DCC booster, assuming reasonable wires (smaller diameter than suspension bridge cables?)
Well, one assumes that if you can send digital information back and forth across the planet via wires across the planet, the way that we’re doing right now, there is no difference between that and being able to send DCC signals–it’s all just ones and zeroes!