What length of track can be driven by one standard 16V/1A transformer?

[Frankv]

I would like to know if there are guidelines as to how long a stretch of track can be driven by one standard 16V/1A transformer? I plan to expand my 8'x4' layout with 2 more 8'x4' sheets forming a U around 3 sides of a 12x12 room. The track will be Bachmann n/s EZ Track. My partner in this venture, my 5 yr old grandson, isn't interested in switching - he wants to see long consists roaring down long straights at top speed. We will have a 22" radius loop at each end of the U, with 2  90 deg turns at the corners. About 56 linear feet of track. Will I need to break it into blocks with insulated joiners? Or can I just gang more transformers on, of course paying attention to polarity? Get a single more powerful transformer? Appreciate any help. I discovered this forum only a week ago and I've learned so much in that brief time. Thanks guys.

[hotrainlover]

I have  a 14' X 22' "L" shaped layout that uses only ONE power supply. 

[Tylerf]

One transformer will power the whole thing, however you may expirience some power dropping on the farthest point from the transformer, a quick fix for this is to simply install feeder wires with a main track bus every 3-4 feet of track. The reason for blocks is for running two or more different trains seperatly with different transformers. Also putting two transformers together to boost power won't work by insted create big issues. Honestly track length really has no effect on the transformer, it's the amount of load on the tracks(ie, locos, or lighted cars.) in dcc we require boosters to essentially break a layout onto blocks and each smaller block has it's own power supply but unlike DC  the control remains the same as every booster comunicates with the command station.

[Jim Banner]

If your power pack can run your train to your (and your grandson's) satisfaction on a short track, it can run it on any length of track as long as the power can get from the power pack to the track.  The track itself does not use any power.  However, contact at the joints and resistance of the rails can cause the track to lose power between your power pack and the train.  The solution is to run a power bus underneath your railroad so that the joint and rail losses do not occur.

A power bus is really quite simple.  All you need is a pair of heavy copper wires, usually 14 gauge or 12 gauge, each a different colour.  These wires can be solid (single strand of copper) which is cheaper or stranded which is a little easier to handle.  These wires should run the length of the railroad under the table.  You could run them right underneath the tracks, but there is no reason to do so unless the table is very wide (say 6' or more) and you need to run more than one pair of bus wires.  It is a good idea to lightly twist these wire around one another, just two or three turns per foot.

Your power pack connects to one end of the bus.  You may want to use short lengths (a foot or two) of #16 or #18 gauge stranded wire between the end of the bus and the power pack so that the heavier wires do not put a mechanical strain on the connections on your power pack.  Then at intervals along your tracks, you can drop feeds wires from the track down to the bus.  It sounds like your layout is an elongated oval.  Just make sure that all the feeder wires from the outside rail go to the same bus wire.  And all the feeders from the inside rail go to the other bus wire.  If you are using Bachmann E-Z track, and you want to use the connector/rerailer sections for connecting to the rails, some special instructions apply.  We will get to those in a minute.  The feeder wires should be no longer than 3 feet but can be quite small, 20 or 22 gauge wire is about right.  Feeders should be spaced not more than 10 feet apart measured along the track and each siding should have its own feeder wires as well. The feeder wires and the wires for the power pack should be soldered to the bus wires using rosin core solder and a soldering iron of at least 75 watts or a soldering gun of at least 125 watts.  Either stagger the joints or tape them to prevent the bus wires from shorting together. 

There is no need for any gapping unless you want a siding where you can park a train.  Then you should insulate both rails at both ends of the siding, where the siding tracks connect to the turnouts (track switches.)  And the  power for the siding should be routed through a double pole switch so that both rails can be turned on and off.  Knowing five year olds (and grandfathers) I suggest you install at least one such siding in preparation for the day when the two of you decide you just have to have a second train.  (Hey, I am a grandfather too, and I too have grandchildren.)  Anyway, just keep adding feeders until you reach the far end of your layout.  There you can leave the ends of the bus wires unconnected for the moment.  Tying them to screw eyes is convenient.  Then they are ready for adding more wire to extend the bus if/when you decide to make the layout even longer.

Now about the E-Z Track.  Adding feeders is easy - all you have to do is substitute a straight or curved connector/rerailer section for a straight or curved regular section of track where you want the feeders.  The problem comes up when you plug in the wires with that special flat plug.  It is difficult or impossible to tell which wire connects to which rail just by looking at it.  But here is a trick that works for me.  After you install all the feeders and have then connected to the bus (one feeder wire to each bus wire, don't worry about which to which) go around and unplug them all.  And take the train, or at least its locomotive off the track.  Then with your power pack connected to the bus, turn it on and turn up the power.  The track power light should be on.  If your power pack does not have a track power light that gets brighter and dimmer as you turn the speed control up and down, add one to your power bus.  An inexpensive grain of wheat bulb from the hobby shop will do the job.  Connect the two wires to the bus, one to each bus wire.  No grain of wheat bulbs?  You can substitute a small dash light bulb from an automobile (but not a tail light, dome light, or other automotive bulb.)  Your track power bulb shows there is power coming out of the power pack.  If it does not light up, then either your bus is shorted or for some reason there is no power coming out of the power pack.  Let's assume it lights.  Now connect one of the track power plugs to one of the connector/rerailler sockets.  The track power light should stay lighted, indicating the track is not shorted.  Now plug in a second track power plug into its socket.  If you have plugged it in right way around, then the track power light will stay lit and you can move on to the next plug.  If it is plugged in backwards, the track power light will go out.  Then the solution is to unplug the plug, turn it over, and plug it back in.  The light should now stay on, indicating that both plugs are the same way around.  Continue on, one plug at a time, until you get them all plugged into their sockets and the track power light is still on.  Sound complicated?  It's not.

A few facts about this bus system, based on a 1 amp power pack:

With 14 gauge bus wires, the farthest point on the bus should be no farther than 150 feet from the power pack.  With 12 gauge wire, not more than 250 feet.

The slight twist in the bus makes it suitable for use with Digital Command Control if you ever want to run two trains at once in the future.  It is very easy to put the twist in now and very difficult to put it in after all the feeder wires are attached.  I highly recommend doing it.

Speaking of DCC, these bus wires are good for a 30 foot bus (#14 wire) or a 50 foot bus (#12 wire) assuming a 5 amp system is used.  Since systems over 5 amps should not be used, there is no reason to use larger wire.  And since #14 building wire is the cheapest, there is no need to use smaller wire.

Looks like I've been a bit (a lot?) wordy again, but that's the full meal deal.

Jim

[Tylerf]

Jim,
All I can say is you could easily write a great how-to model railroading book about every aspect of the hobby.

[renniks]

Frankv,

An 8x4 is great so long as you can access all sides. Shove it into a corner and half the track is out of reach.
Have drawn a plan with two 6x2 sections on left. This gives 2 foot wide access to the ends of loops. Have included one turnout -- add more as you wish. Not knowing EZ-Track, think that I  have used wrong curve sections.
With the power pack/controller in the middle of left side ,it can be connected to center of a power bus (does not have to connect to one end).



Eric Uk

[Jim Banner]

Tylerf,
Thank you for the kind words.

Frankv,
You are of course right that the power pack can connect to the bus at any point.  I like your cut aways in the corners - they are particularly good when it comes to us old guys.  Another alternative is to cover the outside corner with a hill/mountain that is big enough for an access hole inside it.  The front track can still be outside the mountain.  That arrangement can be expanded to a double tracked folded dog bone in the same space.  That gives double the running length but leaves very little room for sidings.  It also requires a duck under at each end for servicing although lift out bridges might be an option.

I like your diagram.  What program did you use?

Jim