Wiring Blocks - Can This Be Done??

[TankedEngine]

I am at the envisioning/planning stage of an HO layout (DC due to budgetary constraints) & I wonder if the following scenario is technically feasible & if there are any articles around that tell one how to wire it -

What I would like to be able to do is have a mainline that meanders around, essentialy in a  loop  - that is divided say into 5 blocks, that somehow is wired so that i can let 2 or 3 consists run on it off the one cab &  is wired up so that when the front train is in Block 1, the following train stops at the start of block 1 [or end of Block 5], & won't enter Block 1 until Train 1 is clear of that block.

This would prevent a 'faster' train 2 from colliding from the rear with a slower Train 1 & allow several trains to be left to circulate the main line safely whilst I was off shunting or whatever.

 I have seen it done with a demo Tram set up running several Trams over the same set of track concurrently, but did not have time to find out how they were doing it.

Tanked

[cacole]

Since you say you have very limited funds, there's no way you can do what you envision without resorting to computer control with a gaggle of relays, or using DCC.

[CSX Robert]

DCC-BitSwitch(they have DCC in their name, but they do make some products for DC) has exactly what you need:http://www.dcc-bitswitch.com/dc_block.htm

[TankedEngine]

Great.

What I was looking for

 Thank you

Tanked

 

[jeffrey-wimberly]

With what that little gem costs you could by a DCC system if you had to do several blocks. For what it could cost for 5 blocks you could throw in some decoders too. Imagine using those switches on my layout. 16 blocks! WOW!

[TankedEngine]

I don't know enough about DCC to debate this - , could you outline how DCC would handle 'hands off' circulation of say 3 consists on a main line so that they don't run into each other?

Would it rely on fine tuning  of the throttles to equal speed after separation established?, or some other approach?

Thanks

Tanked

[Texas Zepher]

DCC-BitSwitch(they have DCC in their name, but they do make some products for DC) has exactly what you need:http://www.dcc-bitswitch.com/dc_block.htm

That's cool for two trains.  But it assumes the second train actually then leaves the control block before the first one gets back around to run into the back side of it.   For three trains one would need at least two of these.  To be safe one needs at least 1 per train, and probably more like one per block, so as you described five.  That is $250.  For that much one can easily get an entry level DCC system and decoders.  It also doesn't seem to say if the reed switches (3 per block) are included or not.  That is additional cost if not.

[Texas Zepher]

I don't know enough about DCC to debate this - , could you outline how DCC would handle 'hands off' circulation of say 3 consists on a main line so that they don't run into each other?

Would it rely on fine tuning  of the throttles to equal speed after separation established?, or some other approach?

Ah, I down played that part of the equation.  One could fine tune the throttle speeds, but there is always the glitch factor in that.  Another way would be to use computer control, but there one would also need to have some sort of train location detection.

I see the bit-switch product also comes in DCC form, but then that further defeats the budget constraints.    I suppose with tuned DCC throttles it would be safer just to have one control section - but still scarry.    So the DC form of the product might be the best option, and one could then just deal with the investment loss when time comes to upgrade to DCC.

[jeffrey-wimberly]

With DCC you can control each train independantly. As for totally hands off your talking about a lot of electronic equipment that you already indicated you can't afford. DCC is as close as you're going to get for the money. I can control three trains on my layout at once. Make them go in oppisite directions, wait at turnouts for another train to clear. But I have to be there. There's no get them running and sit back and forget about it while you leaf through the Walther's catalog. You can come close with a system that's connected to a computer with the appropriate software but even then the trains have to be monitored.

[TankedEngine]

Well if we take the budget constraints and DC factors out of it ,( I assume you would prefer DCC) - is there a feasible set up to allow 3 consists to wander a mainline  safely, unsupervised??;  [kind of moving wallpaper to stuff going on elsewhere in the layout]

Think of it as mechanical ambience.

Tanked

 

[wjstix]

Well if we take the budget constraints and DC factors out of it ,( I assume you would prefer DCC) - is there a feasible set up to allow 3 consists to wander a mainline  safely, unsupervised??;  [kind of moving wallpaper to stuff going on elsewhere in the layout]

Think of it as mechanical ambience.

Tanked

 

The problem is with DC you're controlling the track - put power to the track for the train to go forward, and all engines in that block move at the same time in the same direction...but unfortunately not at the same speed, since all engines run slightly different under the same amt of DC power.

In DCC you are controlling each train - not the track it's running on - independent of the other trains. You can start one train going say 25 scale MPH, then start the second train and bring it up to the same speed, and then the third train after that. It's probably impossible to get them to be exactly the same speed, one will inevitably be a tiny fraction faster or slower BUT you can slow down or speed up any of the three trains anywhere on the layout, no matter what block they're in - or even if you don't have blocks.

[BigRusty]

I built my last layout that way. I used 10 blocks and the NMRA Twin T detectors for block occupancy. Similar circuits can be made on perf board or ready made. I installed a short section of stopping track before each block signal. When block A was occupied the signal turned to Red, and the followuing signal to yellow. Power to the stopping block was cut off so no train could pass a red board.

I had one 5 block section wired to one cab and the other to a second cab. The track layout was a folded dogbone with double track in the sqeezed portion in the middle, but it was actually a continuous loop.

I ran 5 trains hands off whenever I wanted to just train watch, or to work on some area that wasn't affected by the trains going by.

The same thing could be done with DCC, but you still have to isolate the blokcs for block occupancy detection unless you use one of the infra red detectors.

[TankedEngine]

 BigRusty

This sounds promising - you have actually got to where I was headed - something tied in with signals.

How many Twin T detectors did you need? [dumb q. but at genisis of MR electronics]

Tanked

[wjstix]

You can do something similar in DCC. 

Most DCC decoders can be set to work on either DCC or DC, or just DCC. You can set the decoder so it only works on DCC, and then set up a separate short block of track ahead of a signal, and set the signal so that when it shows red for stop, the section in front of it changes to DC. An engine entering the block will stop. When it changes to green, it switches the block back to DCC and the train goes again. Under DCC momentum settings, the start and stop can be very smooth and not zero to 60 in one second like in DC.

[BigRusty]

You need block occupancy detection for each block.

I forgot to mention 3p2t relays for the signal circuit. If block A is occupied, the signal would be red, but block B would be green because it is not occupied. The wiring diagram lights either the green if A is not occupied, or if A is occupied lights the yellow.

Since I ran some long freights, I needed to have some resisters between the wheels and a light in the caboose, else B would not be shown as occupied resulting in the rear end collisions you are trying to prevent. It is better to have the blocks longer than the longest train you expect to run.

[CSX Robert]

You can do something similar in DCC. 

Most DCC decoders can be set to work on either DCC or DC, or just DCC. You can set the decoder so it only works on DCC, and then set up a separate short block of track ahead of a signal, and set the signal so that when it shows red for stop, the section in front of it changes to DC. An engine entering the block will stop. When it changes to green, it switches the block back to DCC and the train goes again. Under DCC momentum settings, the start and stop can be very smooth and not zero to 60 in one second like in DC.

I was going to mention this, and you beat me to it. What Tanked is wanting to do can certainly be done without the added expense of DCC, but the big advantage to using DCC is being able to use the momentum settings of the decoders. If the trains are close to the same speed and you have large momentum settings, the faster trains probably will not even ever come to a complete stop. When they enter a block that has been switched to DC(you can also use a DCC "set speed zero" block, which has the advantage of working with ALL decoders, including those that do not support stop on DC) they will begin to slow down. When the train in front clears it's block, the following train will immediately begin speeding back up.

[TankedEngine]

Can you give the names of some 'off the shelf' programs  that run trains I can read up about??

Or better still, offer some recomendations?? 

Thanks

Tanked 

[trainnut1250]

Tanked,

I did exactly this on an old Marklin Layout with detectors and relay boxes.  I ran three trains, hands off, with a high degree of reliability.  It was a little jerky, but it worked.  You would need detection and relays.  Sounds very similar to the Twin T described earlier.  The system I used needed a detector and relay set for each of the blocks. 

Rob paisley has a series of build it your self detection circuits at his site, you might want to check it out.  He also sells circuit boards for some of his designs.

http://home.cogeco.ca/~rpaisley4/CircuitIndex.html

In DCC, the Lenz gold series decoders have a feature that can stop the decoder by using a capacitor across the block, I don't have all the details, check out their website...might be useful to you in this application.

 How long is the mainline run here??  How long are your trains??

Guy

[TankedEngine]

The  mainline run will be a folded over dog bone, about 50' and I won't be running long trains, say loco + 8 wagons max. If I put in a relay or Twin T  system as described by others in earlier posts then if I have 3 trains on 'auto pilot' one might be an engine on its own etc, so not looking to fill the mainline with hardware. while they circulate I could be in a corner of the layout with a logging train or something like that.

Tanked 

[TankedEngine]

CSX Robert

DCC-BitSwitch(they have DCC in their name, but they do make some products for DC) has exactly what you need:http://www.dcc-bitswitch.com/dc_block.htm

 

 

Tried the above link without success.

Do they have a different site now??

Tanked

[CSX Robert]

Apparently they have taken the dash out of the website name: http://www.dccbitswitch.com/dc_block.htm

[TankedEngine]

CSX Robert

Apparently they have taken the dash out of the website name: http://www.dccbitswitch.com/dc_block.htm

 

That works.

Thanks

Tanked