Without each track being

Without each track being powered separately you will have all  locomotives running at the same time.  If they have sound , it could be annoying.  I prefer to be able to turn on the track I need.

Silent except when addressed

Couldn't most of them be silent except when addressed specifically?

I have heard that they don't turn off completely if they are sitting on a powered track, but do they have to make noise (or move) if they have not been called on??

Kinda...

Decoders can be explicitly configured to

"Make sound when track-power is turned-on, IE if there's rail-power, there will be sound"

OR

"stay silent until explicitly addressed/throttled-up, irrespective of track-power condition"

The 2nd option would solve the audio problem of 
"I power-up the layout, and the entire loco roster immediately starts making noise"...

...but it's up to the Human to explicitly make that decision, and program the decoder(s) accordingly...

Correct, Any DCC loco, INC a DCC sound-equipped loco that is "sitting silent",
is still drawing some ammount of power from the rails.
(Maybe not as much per-loco as when hauling a heavy train upgrade with "Full Noise = ON", but some...
...just like a computer which is "in Standby mode", as opposed to being explicitly turned OFF),

This is why the reccomendation for "DCC layout power distribution planning" often includes setting up roundhouses and engine-terminals with their own breaker, if not their own discrete Booster.

The idea is simply that these locations will be where a lot of locos will congregate ,
and thus that location will demand a comparatively lot of cumulative power/current on "layout power-on",
as all the locos in the roundhouse/terminal try to "power up" simultaneously...

(Flipside, if a short happens somewhere "in the terminal",
where a lot of short-inducing loco movements might logically occur, 
the breaker/booster will take-down and thus protect only the terminal,
leaving the rest of the layout Alive-and-Still-Running...)

Happy Modelling,
Aim to Improve,
Prof Klyzlr

Count the solder joints

You really do need to wire each track separately, and what's more, you probably want to wire a separate on/off switch into one of the feeder wires for each track.

+ Wiring the tracks will be less work than tweaking the CVs on every locomotive you have.

+ Wiring the tracks all together in a daisy-chain series doesn't decrease the number of track-to-wire solder joints, it doubles the number of such joints required (not counting wire-to-wire soldering).

Your series idea just reduces the amount of wire-to-wire soldering where you bring the feeders together. You can get a terminal strip for that if you want to save time on that.

You could use a rotary switch instead that would let you power on at most one roundhouse track at a time, but that's limiting, and you'd probably find the necessary wiring more confusing to do.

If you solder feeders to the dead ends of the rails inside the roundhouse poor soldering will be hard to see, but you'd need holes in the roundhouse floor. If you wire the feeders close to the turntable, the droppers are more visible but easy to get at. Either way should be pretty easy to do the soldering at your bench first and then drill a hole between the ties for the wires to go down through after you place the track.

DCC & Sound Locomotives

If I take a DCC/Sound loco and set it down on the tracks it doesn't automatically start making sounds,.... does it?
It also doesn't start running, ....does it??

Don't I first have to bring up its address on my NCE controller for it to start making sound and motion?

Kinda...

It does, IF it is soo-configured
(EG Tsunami default setting - TSU CV116 / TSU2 CV114 aka "Engine Exhaust Control") 

it does NOT, IF it is soo-confiigured (EG Loksound default setting)

If by "Running", you mean "start physically moving down the track",
then NO, that should NOT occur...

(if it does, you either:
- have a wiring fault in the loco
- have a damaged decoder
- have a DCC throttle already "sending speed comands" to the address of that decoder
- have put the loco down on an Analog DC track, or something the decoder thinks is Analog DC)

...Again, the "Have to bring it up on a throttle" thing is not dependent on the Throttle End of the situation,
it's all about how the Decoder is configured to behave...
(See above)

Happy Modelling,
Aim to Improve,
Prof Klyzlr

The answer is, it depends on

railandsail, I have some DCC

railandsail,

I have some DCC and DC locos.

The DC ones are parked in the roundhouse with those track feeders turned off (SPST).

If I was entirely DCC,  I would have all tracks wired like you plan

Having all tracks powered at

Having all tracks powered at the same time with engines sitting on them not only produces the noise issue that has to be dealt with, but also takes a certain amount of power from your power source.  Unless you have a separate power supply for the roundhouse, you have the potential of reducing the power potential in other areas of the layout.

Similar Situation in my Staging Tracks

The powering of my staging track areas are somewhat analogous. I have 3 separate staging zones of 6 tracks in each. Its my intention to cut all power to them UNLESS I am extracting a train from one of them. Then only that one area of 6 tracks is powered up. Yes I could wire and switch each individual track, but don't think that additional wiring and switch control is necessary?

but also takes a certain

I think I read where the new PSX power shield breakers have built in capabilities to handle in-rush power needed to handle many such situations?

"I think I read where the new

Those could be handy.

Another point of view

Brian,

All of my round house tracks are wired to one kill switch that powers them all on or off at once similar to what you are proposing.. I have used this arrangement for years with DCC sound equipped locos with great results. I don't have so many tracks (8) that the inrush is an issue and the sound from the locos powering up at once is noticeable but not objectionable.I use this arrangement for OPs sessions and it works just fine

I would suggest that you want the tracks powered off for the all of the other reasons stated and also because you don't want stored locomotives to be subject to shorts and the reset cycle if you can avoid it. I agree with the other poster in that you want to solder at the ends of your rails buried in the round house where no one will see the solder job and you don't have to worry about hiding your work.

Guy

Access and power to engine house

  I made my engine house structure removeable but the floor and tracks stay in place. The bottom of the walls have small pegs that key into holes drilled in the floor. This lets me wire the rails thru on/off switches mounted on the fascia. I only have three tracks in the engine house but some of the engines in there are long term storage so should not be idling during operating sessions. ...DaveB 

@DaveB

I would have liked to do that as you did, but my steam engine roundhouse just would have not stood up to that type of construction,...particularly when I may very well might make the roof removable at times.

My diesel engine repair house (over near the steel mill) , and my double deck diesel engine repair house up on the top deck near my SantaFe station will likely have that same location pins arrangement.

My track connecting feeder wire will likely run along tight to the deck surface and be hidden by the ground cover that usually is found in those roundhouse areas.

@Guy,......Nice to hear you have operated a similar arrangement successfully for years,...encouraging.

  "my steam engine

Hi Brian, Yes it took a bit of engineering to make my engine house structurally stable when lifted off the base. I ran cross ties across the width every 4 scale feet and about 2/3 of the way back from the front is a full width bulkhead type wall that extends up in the roof gables. The roof sheathing is thin plywood glued to the top of walls and to a ridge beam. Eventually I'll cover the roof and sides with scale corrugated tin sheets.....DaveB

Mini male/female connectors

Would it be possible to use something like these mini connectors to wire my roundhouse tracks in an individual manner?

Mount them on the base plate of the roundhouse such that they just plug into their receptacle side mounted in the plywood deck, or vice-versa??

Brian, no matter what you decide...........

.....to do, you are going to be stuck doing a lot of soldering!  You have 5 tracks in the roundhouse so that’s a total of 10 rail/wire joints.  Can you access under the bench work that is under the roundhouse easily?  If so, you could use plugs on the end of the track feeders and drop them down for plugged wires coming from the fascia for power.  Don’t be lazy, put an on/off switch on each track!  If you can’t easily access under the round house here’s my idea. Attach your feeders to the very end of your rails at the back ( like someone already suggested) and run them out through the wall at the bottom with tiny plugs.  Now run your feeder wires with plugs up from the bottom and make your connection outside the back and on top of the bench work.  You can always cover the plugs with scenery, lichen, barrels etc so they won’t be visible but still accessible.

Looking at your layout it seems you are doing a great job and taking time to make it look really nice.  Take the extra time and effort with this.  You’ll be happy you did down the road.

Peter

Tiny Plugs

@Peter,
I'm trying to image your suggestion,...what type of tiny plugs are you suggesting? Something like those I pictured above?

Removable signalsWed,

Another discussion of Micro Connectors right here on this forum,
https://forum.mrhmag.com/post/micro-connectors-12199291

Why not cable-ize it?

Buy a 5' cable with male-female connectors on it, at least 10 pins, mate the connectors, cut the cable in the middle, strip a foot of the outer sheath off each piece, connect the 10 wires to your rails, connect the other 10 wires to your switches, or whatever. Don't waste your precious time soldering tiny connectors, for heaven's sake.  These are single locos running at low speed on those short tracks, so the usual caveats about wire gauge don't apply, within reason.  I wouldn't use a cable with 30ga wire, but most robust cable options use at least 26 ga.  Something like a 25 pin RS232 extender cable would do just fine, just make sure the cable is fully populated with wires.

Just my 2 cents.

Blair

flex the flex

The tracks are flex, right? So what about this: Nail down the flex at the end next to the turntable (with nails, not glue), and wire the pieces to power there (you can wire them on the bench then drill a hole between the rails after you determine where it has to be). Leave the flex sticking into the roundhouse loose. When you want to remove the roundhouse, slide it back away from the turntable, flexing the flex so it fits through the door. 

The only electrical connectors you need between the roundhouse base and the plywood below would be for lights, which you won't have until you finish the interior out. At that point you can nail it down for good.

A couple of points about sockets

Bear with me a bit, because this is about mounting electronic assemblies on top of each other, not necessarily model railroad objects.  But it should still apply.  My first recommendation would be to run a cable from the tracks and any lighting down through a snug hole in the roundhouse floor through a larger hole in the supporting surface.  The hole in that supporting surface should be large enough to allow about 1 inch on any side of  whatever connector you attach to the cable.  The roundhouse should be large enough to cover that hole anyway.

If you insist on using pins fitting directly into a socket under the roundhouse floor, consider this:  When you start stacking things together and there are connectors that have to mate to make them work, one thing that is going to happen unless you take steps to prevent it is mashed pins.  This can happen when sticking a printed circuit board into an edge connector, it can be sticking a chip into a socket, it can be when seating a small board onto a larger assembly.

I'm going to skip the "If it's possible to plug it in backwards, it will happen" scenario because something like a roundhouse is going to be pretty tough to inadvertently try and set back on the layout backwards. :D

Anyway, the more pins there are that need to go into a socket, the more sockets involved, and the larger the object  being added compared to those sockets, the more likely somethings going to get bent.  And you only need one bent pin to really mess up your day, especially if you don't find that out until you apply power.  This is commonly referred to as "Letting out the magic smoke" or "The blue flash test", but I digress.

If you are going to try and mate something large like a roundhouse onto something tiny, like a socket somewhere underneath it, make sure that you have several guide pins to key the object into the exact orientation and position over the socket. My suggestion would be to drill 4 holes in various accessible points in the roundhouse interior and on through the supporting surface underneath it, then glue short lengths of brass tubing into those holes in the surface, flush with its top. Fit pieces of brass rod (or tubing) that fit exactly into those lower pieces of brass tube, making them at least 1/2 inch long so that they ensure everything is lined up before the pins under the roundhouse make contact with the socket.  Slide those pieces of rod or tubing into the roundhouse floor and the tubing in the surface below, then carefully epoxy them into place.  This will give you your guide pins. 

As far as the sockets themselves, my suggestion there is that you cut out a couple ties in the track at the back of each stall and make your opening for the sockets in the roundhouse floor.  Mark the spaces on the supporting surface, then remove the roundhouse, install the bottom sockets flush with the supporting surface.  At this point, slide the roundhouse back down in place, add the wires to the proper pins for the connector to each stall's socket, and push the connector down so the pins seat into the socket.  Finish up by gluing the connector in place to the roundhouse floor.  Let everything set up solidly before pulling the roundhouse up to remove it.

Again, from my experience as an electronics tech on the bench, the more pins that are being aligned and connected, the more likely that without a very solid set of alignment pins, you will have bent pins, and the more force (within reason) is going to be needed to seat or unseat those pins when installing or removing the top object.  Once more, this is why I'd personally use a cable with a connector feeding through a larger hole in the supporting surface rather than mating the connectors directly from the roundhouse floor to the supporting surface.  If you insist on mounting some sort of socket to the floor of the roundhouse, then my next suggestion would be to mount all the connecting wiring  from your power and lighting busses to cables that could plug into that socket through a larger hole in the supporting surface.

Hope this helps.

Janet N.

Brian, I make my own plugs using.......

......what I think they call "headers". I mainly use then as tender-loco connectors. Really easy if you know how (and like) to solder. I’ll post some pictures tomorrow for you see what I’m talking about.  That fellows idea using a multi plug cable is not a bad idea either AS LONG as you can get under the roundhouse to plug and unplug it.  I suppose you could hide the plug on the surface and cover it with a lean-to or small shed up against the back wall. Those plugs are pretty big in HO scale!

Peter