The Christmas layout I had planned to have finished for this holiday season hasn’t quite gotten there yet due to a number of factors. One thing that is still vexing me, and which Google searches have been fruitless in resolving, is whether it is possible to do block detection / control on a DC layout. Basically, I’ve got a two track main, but only a single track through a tunnel and over a bridge. As we all know, trains (and planes, cars, people, etc) can’t occupy the same space at the same time, so a blocking system is needed. Is an automatic block system possible in DC, and if so, how? Does anyone have any resources they can point me to? Thanks in advance, and Happy New Year.
Edit - If possible, I want to avoid optical (IR, etc) detectors, since this will be under a Christmas tree for part of it’s life, with varying lighting conditions.
You can ‘automate’ it - But the cost is going to be more that you have in the layout! I agree that optical detectors can be ‘iffy’ depending on lighting conditions. Use IR detectors and you do not have a problem. CMRI(Computer Model Railroad Interface) is available at the following URL:
Basically in your case, what you need is detection of ‘anything’ in the single track area, and power being turned off on the double track approaches. You will also need to reverse polarity and align the switches. I would not even ‘guess’ what this will cost you. I have 8 blocks of signalling on my layout - about $500 for detectors/signals/logic/power supply. Automation is not cheap!
CTI has a system that can be used for DC. You would need a computer but you may be able to do it for about $100. Check out www.cti-electronics.com. The starter set board has four sensor ports and four relays. You would have to add the IR sensors but they are available from CTI with instructions. The documentation can be down-loaded for free to see if that is what you are looking for.
that looks like something I saw at the TCA York meet a year or so ago and was fairly impressed by. I can’t recall if it’s the same company or not, but it is along the lines of what I’m looking for, thank you BTW, the reason I’d prefer not to do DCC on this particular layout is that one of my locos (a Bachmann 2-6-0) doesn’t have DCC installed, and from what I’ve heard, it isn’t easy to get a decoder into it due to some electrical concerns (isolating the frame, etc).
IR detectors and Light sensing detectors are two seperate things. IR detectors will only really be affected if the layout sits in bright sunlight.
BTW: Yes it is possible. MRR had an article on how to do it in a 1992 magazine article. However it’s vastly outdated.
Digitrax has a block detection system that will work with DC. You have to create a circuit attached to a relay when the block ahead is occupied.
A simpler solution however might be to use a “feed from the points” turnout. With this type of turnout, power is fed down one leg at a time. So if you are approaching the points and they are thrown against you, the train stops dead.
The Miniature Railroad Club of York (www.mrrcy.com) is holding their open house. The last open house is this weekend. They use a DC block control system.
If you come by, you can say, “Hello” I’ll likely either be by the pierfront or the steam engine facility.
Man, talk about bad timing, my brother and his family are coming up this weekend to visit. If York were closer (I’m about 2.5 hours away), I’d try to convince them to go with me
EDIT: The above system is labeled for DCC use, but it MIGHT work in DC. You should contact the company and see what they say. If you wire the polarity properly, it might not be an issue.
You don’t have to isolate the frame, you have to isolate both motor brushes from the frame (and from anything else that’s electrically “live”).
Either way, I certainly wouldn’t let one possibly difficult loco dissuade me from using DCC. The wiring simplification alone, to do what you are proposing, would make it more than worth your while.
I’m hoping to find someone online that’s done this…I’ve seen lots of “how do I…” for this loco, but no “how to”. I don’t want to take it apart without knowing what needs to be cut/removed, etc. I’ve got a few good leads, so hopefully one will follow through.
I agree wholeheartedly. I will be using DCC on my main layout, but since this is a smaller one that would only be running two trains around the tree (technically, 4, but the other two are other gauges and won’t be sharing track with these two), I was hoping there was an easy out for using DC only on this. I may decide to just run two mains through the tunnel and over the bridge to simplify things even more.
Have you looked at the Atlas system. They have detectors setup for DC, but you still have to divide the mainline into a number of blocks to isolate each train. Nothing in signals or block detection is really cheap but this is fairly low cost and it works right out of the box. Dick Foster
that actually looks pretty close to what i’d like to do. i can’t tell, though, from their page, if it just controls the signal aspects, or includes stopping locos, etc…
You may want to look at www.oaktreesystems.com for solutions to DC control. This is not necessarily a super low cost solution, but is available for those who don’t want to convert to DCC for some reason.
