DCC Blocks

I am currently in the final stages of the planning of my layout and I was wondering how big a DCC Block can be to run smoothly.

 

That all depends on the power output of your system (how many amps) and the draw on that section. A Power District can be a yard, long stretch of main, or a combination. Also, if you want on/off switches, I would block it as if it were signalled.

 

I've got zero experience with DCC but I am wondering if electrical supply would be the only reason to wire track into blocks with DCC other than reverse loops, wyes etc.? Is there any harm parking unused DCC locomotives on live track or would it be better to kill the power under stored locomotives?

 

The only reason to kill power to an engine on a dcc system is if the engine is the analog (non-dcc) engine on the layout. Sometimes the analog engines can hum quiet noisily and some fear over the long term the engine can be damaged.

A block can be long or short depending on what you want to use it for. A block is just track that is seperated from other track with rail insulated joiners. If you are lazy, more blocks is better since finding electrical problems will be isolated to one block. If your layout is all one block, then you have to suspect all the connections on the layout. If your layout is divided into many blocks, then you have to only suspect the connections in the block that isn't working.

Blocks is one of those hard questions to answer. If you are thinking of going computer run or signal run, more blocks is better. Almost every piece of track is its own block on my layout; every turnout is its own block.

At present I have about 120 feet of track laid (about 1/3 of my layout) and I have around 50 blocks. I am doing over kill on my layout for blocks, but I am doing it for computer running in the future.

When you are newer, the tendency is not to want to do blocks because they seem somehow intimidating. Remember, you don't need toggle switches on blocks.

In dcc, a standard that is being flogged, but not picked up that much is to have feeders every three feet. If you do this, then each piece of flex track can be its own block. You just hook them up with non-metal railjoiners instead of metal ones. The feeders give the power to the rail and the dcc signals, so it really doesn't matter if you use metal rail joiners or not.

 

I thought the reason for doing blocks is to divide up the power usage. Like my layout will have one major yard (Austinville), a major passenger and freight station, Service station, and Roundhouse with turn table, so naturally this will take up a lot of power. In case your wondering, I'm doing an N&W Branch-line "New River Branch" in the Virginian Mountain. Will one block really be able to handle a power usage of a large layout?

 

With DCC, there are really only two reasons to install blocks:

1. To isolate areas so that a short in one area doesn't shut down the entire layout. This would be more properly called zones than blocks.

2. For signaling.

It sounds to me like Rick is over doing it with blocks but more power to him. I have signals on my layout so I have blocks plus I have broken the layout into multiple zones.

Assuming that Poltergeist is really talking about zones, it is really up to you. I have about 7 zones on my layout. Yards are usually a single zone while long mainlines are combined into single zone. I did it this way since there are seldom derailments that could cause a short on the mainlines. Derailments are more of a problem in yards.

David


David

 

I have taken this from a dcc topic at the Atlas forum and pasted it here. It kind of addresses what we have been talking about and it is easier to paste then do another long reply:

"A block is not a power district and a power district is not a block.

Power districts: the best way to understand them is having your layout divided into three separate areas, each run by its own power pack. Light bulbs don't create a power district, a power district is run on its "own" power.
Blocks: lets say you have three pieces of flex track all joined by metal joiners with one set of feeders or more going to the power bus (the two sets of wires running underneath your layout). These three pieces of flex track are all one block, assuming they are part of a larger layout. Now take those same three pieces of flex track and hook them up with insulated rail joiners; now you have three separate blocks. Each flex track would need its own set of feeders.

One turnout can be its own block if it is hooked up to all the other track with insulated rail joiners (again, it needs it own feeders). In fact, I am describing my layout, with gobs and gobs of blocks. I am anticipating computer running and I plan on using the blocks for the computer to identify a location of track. So in the computer I can tell it to tell Royal Hudson 2860 to slow to 40 MPH in block 29 and come to a halt in block 30.

Normally advising people on issues in model railroading is fairly easy, but how many blocks on a layout is more difficult to say. Blocks depend on laziness, confidence, signaling, computer running, and probably some other issues I haven't thought about.

Laziness: the more blocks the better so when you have an electrical issue and block 29 is the culprit then you don't have to worry about the remaining blocks. When you entire layout is once block, then where it the electrical problem? Everything is suspect.

Confidence: newer folks such as I are easily intimidated by concepts we don't quite understand. Blocks is one of those issues, particularly if you are adding dcc but have never had other layouts that had "traditional" blocks. So the inclination is to add no blocks (a big mistake).

Signaling: blocks are integral to signaling.

Computer running: blocks help locate running stock on a layout.

Davie,
I'm not light bulb in the know but I do know some recommend it; some don't.
Using the PM42 from Digi I will be creating separate areas that although all powered by the same booster (power source plus amplification of the signal), will be independent of each other; so that when a short occurrs, only that area is shut down. But each area will have many blocks. These blocks will be hooked up to the BDL162, in fact many of the BDL162 as I have lots of blocks to detect. Each BDL162 can detect 16 blocks.


So I will have a block (lets say one piece of flex track) hooked up to a BDL162 block detector, then the BDL162 hooked into the PM42 districts. So each district will have many blocks, but all powered by one booster.
The most engines I can run in N scale on my layout (due to the fact there is room only for 3 operators) is 6 engines - 3 trains each double headed.

So my 5 amps will be more than enough power, therefore I don't need more boosters, but I need districts that will shut down if they have a problem, without shutting down the entire layout."

 

This is all very interesting. I've had DCC for about 4 years now on an in process layout. As layouts go, its fairly large, 19x25', two decks. Except for tracks in staging yards, I have no "extra" blocks. My bus runs beneath my roadbed with feeders (eventually) to each piece of rail. Eventually because I laid my mains with Atlas code 100 with plans to replace with handlaid code 83 later. For now the code 100 has very few feeders, and works admirably. Anyway what I wanted to add to this discussion is simply this: Don't worry about blocks to the point of delaying construction. You should have a bus wire running below your track. If you decide in the future that you need a section of track to be an independant block, all you need to do is gap the rails, cut the bus and reattach the severed section to the booster, usually thru a circuit breaker. I use a 5 amp Chief by Digitrax and haven't yet needed more power, when I do, I will do as I just described. There have been a few times over the years when i wished I had blocks to turn off for finding a short. And when someone runs thru a turnout thrown against them my entire layout shuts down. I don't have people over to operate often enough that this is a major problem. If it were, I would create blocks right away. As it is, I have plenty to do and will put off installing blocks till I need them. I will have a better idea of where I want them gapped then.
To sum up the comments so far, reverse blocks definately need gaps and are their own block. Areas you want to be able to kill track power should be their own block. Installing switches to kill power to each block will aid in locating shorts. Signalling and/or computer assisted running will require blocks. All these issues can be addressed later, don't waste time worrying about them now. Lay some track!

Gary