Power districts in DCC layouts have been recommended by several sources for easy troubleshooting if nothing else. What's everyone's opinion on how big should they be?
I've got 120 feet of single main line, 4 significant sidings/branches/industrial parks, and a big classification yard (16 ft and 14 tracks).
I was thinking of splitting the main line into two districts, one for each of the sidings/etc., and the yard into two. Or, am i better splitting the main into 3 or 4 and not separating the sidings into their own?
I would do what seems intuitively the most effective for you, and it should work provided you have the power draw reasonably assigned between the two or three districts you choose. By that I mean if your yard is going to be a busy place with several engines and lighted passenger cars operating at once, it should be a district all by itself, but maybe two makes more sense.
I simply broke my layout into four discrete sectors and made them the four benches that I have bolted together in a square that surrounds me and the operating pit. I don't have boosters, but used tail light bulbs wired in series to control shorts, with each bulb responding to shorts on the bench it serves. A booster should do the same...be wired in such a way that it powers and manages shorts on a sensibly sized and functional area of the layout.
If it were me, I'd make the main one or two districts, as you have suggested, and the yard and engine servicing another. For the main districts, any sidings or spurs would be included.
-Crandell
It really depends on the size and how your layout works.
My layout is in a single car garage. I have three sub-power districts divided by using circuit breakers from one 5 amp booster. Basically, the room is split in the center down the long part of the room. Each side is in a sub-district. I also have an upper level. That is the third sub-district. My layout uses 12 locomotives, but not all at the same time.
The power districts in our club are divided by areas of the number of locomotives in use. The main yard and loco facilities is one, staging is another. We have a branchline that is another. We also have a subdivision on an upper level which is another. Then the main lines are divided into four parts. All are powered by individual 5 amp boosters.
There are two purposes for using power and sub-power districts. One is due to the size of the layout and the number of trains running at one time, you need more power. The second, which is actually sub-power districts, is to separate the locations where most switching takes place and thus possible derailments which would affect other parts of the layout.
For your layout, one power district may be the yard and engine terminal. This can be divided into two sub-districts, one for the yard and the other for the engine facilities. The rest of the layout (the other power district) can be divided into sub-districts at the locations of the towns with their switching areas. This would include the mainlines. As an example, if you had a large loop with four towns, each in one of the corners, the sub-power district for town B would start middle way between the preceding town (A) and end middle way to the following town (C). It would also include all sidings and switching areas. That way, a train that shorts the power while switching town B won't take out the power for any trains switching towns A, C, or D.
There are other ways to do this of course, but should be set up in some sort of logical way. Without seeing a track plan it is hard to visualize what you really have and how it is arranged.
Hope this helps.
Elmer.
The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.
(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.
"It really depends on the size and how your layout works."
This is so true, there is no set formula for breaking your layout up into power districts. Right now I have each one of the main lines on their own separate district and the entire branch line on it's own district and the main yard will be on it's own eventually. The hidden staging in the next room will eventuality be #4. I consider the sidings to be part of the branch line so I did not separate them as I dd not see the need to.
In all truthfulness some times it's not entirely necessary to break your layout up into separate power districts. I have a friend who has an odd shaped layout it lives in a 40'x 10' space right now it's a point to point set up and he has it broken up into four districts with four separate power districts. His wiring is impeccable, down right flawless and he is running an NCE power House Pro so he has plenty of power. He does do a lot of switching on his layout but never runs more then three trains at one time. So why all the over kill and extra added expense. Piece of mind? This may be of some help. http://www.wiringfordcc.com/wirefordcc_toc.htm
I agree with others, what you do is up to you to decide. My Santa Fe layout is three decks, all three have major yards/staging areas. I use NCE, and broke the railroad up into 4 power districts. One is strictly on the top deck, the Oklahoma City area which has a lot of switchers working along with locals and through trains.
Leaving the Oklahoma City area is the second power district, strictly mainline, but with two towns with a lot of switching, and the main goes into hidden staging, while the Enid district starts down a helix to a second deck. Part of the second deck is branch mainline with two towns that have some switching. Rest of the second level is branch mainline into the town of Enid, which has 13 grain elevators, a refinery and a lot of switching. This stretch is the second power district. Out out of Enid the line continues down a long hidden grade to the bottom deck. This line is on the third power district and controls a BN mainline and the ATSF Enid district. Fourth power district is the large staging area at Waynoka OK for both ATSF and BN.
Now to some, this is overkill and I could have done away with one power district for sure, but the bottom line is: during an op session, a lot of trains are moving, and a lot of locals are localling, and a lot of yard engines are switching. With two powered units on each consist (plus some dummies), that is a lot of diesels. IF there is a short, I can quickly isolate the district by spotting the blinking light on the booster, and home in on the problem easier and quicker. Also the other districts can keep working while I find and fix the derailment. That is the major reason for me to have the districts. More expensive, really no more wiring than one district, and adequate power for engines at all locations.
pastorbob