Wiring Long Sections
Question: I'm planning a OO model railway in my garage which is to consist of a double track loop with two different station termini running off, each having two or three sidings. The loop itself would be around 18 metres in length. I have read a chapter on wiring in a book by C J Freezer which, if I understand it correctly, suggests that because of the electrical resistance of the rails, one needs to break up the layout into shorter isolated sections each of which must be fed power directly; simply connecting a controller (I was intending to buy the Hornby one) to each of the two main loops would result in poor running of the trains. Is this the case and if so how would I rectify the problem? I want to keep the wiring as simple as possible, for the time being at least!
Answer: The point of greatest resistance is between rail sections across the rail joiners.
Provided that all af the track is easily accessible the simplest way to start is to just connect the wires to a spot somewhere near the centre of the section and see if you have any problems with running. If the trains tend to run slow toward the ends of the section then you drill a small hole outside of the rail on either side of each joiner and run a wire down through the hole on one side of the joiner and back up throug the other. Solder this wire to the rail on both sides and you have provided an alternate electrical path past the joiner.
If there are sections of track that will be inaccessible (in tunnels etc) you might want to solder a wire between rail sections before placing anything over the top as it will be difficult to add them afterwards. In this case you can just loop the wire around the joiner since the track wont be visible.
Under no circumstances solder the rail to the joiner as the rail needs to be able to move in the joiner to allow for expansion. You also need a small gap between the rail ends in the joiner to allow for this.
If you still can't get decent running with all of the rail joiners bypassed with a soldered wire then that is the time to think about running duplicate feed wires to the troublespots.
The alternative if you have a really long section of track is to isolate the track in several places so as to make separate electrical sections from it. You can then just loop the feed point for each section together when you wire the layout. This will result in each feed supplying power to a shorter section of track from the start and will also allow you to change the wiring so as to make them separate electrical sections at a later date (allowing you to run more than one train independently controlled on the same track provided that you have enough track sections). A circle of track broken into five or six sections will allow two trains to run on the same circle.