Reverse Loops Make Sense

[SpaceMouse]

I was looking at the DCC primer and there does not seem to be anything wrong with reverse loops as long as you are running DCC (and don't plan on inviting anyone over who has an analog locomotive.) What is nice about the reverse loop is that it doubles the pathways across a landscape and double what you can do, e.g. drop off a loaded car on the way out and pick it back up empty on the return.

According to the primer again, DCC can handle the transistions flawlessly if the loop is isolated and it has a booster.

But I've heard here that there can be problems. What's up with that?

[rrinker]

I don't think they're a problem in DC OR DCC, just that in DC they are a pain because you have to remember to throw the toggle switch all the time, or your train stops dead with a short.
DCC makes it easy - you can change the 'polarity' (technically, since it's a square wave signal, the phase) right under a moving train and nothing happens. But DCC also allows you to use a device to automate this switching. You don't need the expense of a second booster unless you actually need the extra power. There are auto-reverse devices from Digitrax, MDC, Tony's and others that will do the job just fine.
The problem comes in if your reverse section is too short, and you have metal wheels entering AND leaving the insulated section at the same time. The auto-reverse can only switch one way at a time, if the entrance and exit gaps are both bridged at the same time it will short, there's no way it can switch that would keep things happy.

--Randy