2 wires? - your 'avin a larff.

[Clive Mortimore]

I have a moderate sized 00 scale layout running radio controlled battery powered locomotives. So far I have 49 converted locos. It is a cumbria inspired continuous run with 2 main lines, a continuous run branch and small goods yard plus loco shed. mid 1950's to mid 1950's so I run steam and early green diesels.

 

Power on board = battery, a backwards step - Actually it is a forwards step, Why? because you get none of the problems associated with delivering power and command signals through the track and wheels. This has been a basic problem even with DC. There are lots of work arounds but that is what they are, workarounds!. with battery power you get pure PWM modulated DC delivered to the motor, no workaround needed.

 

Technology has not reached a point to make a battery that is small enough and provide long term power requirements for a train - how long is long term? My operating sessions last from 2 to 3 hours with 12 to 15 locomotives per session. My rule of thumb for a 3 hour session is each loco pulls at maximum load for half an hour  and sits idling in the fiddle yard for two and a half hours. That's 56 circuits per half hour at scale 60mph!

 

Take a large pacific loco as an example. This typically requires about 400mA of battery power to pull a 12 coach express at scale 60mph for 1 hour. The receiver/voltage regulator needs less than 20mA per hour when idling. 30 minutes pulling needs 200mA and 150 minutes parked needs 50mA. That means the battery needs to supply 250mA. A battery that size is easy to fit, large loco tenders can have at least 500mAh with ease. Lets do a large exhibition layout and a 8 hour operating day. There are 16 locos per running line, not excessive in my experience. Half an hour pulling and seven and a half hours idling needs 200mA + 150mA = 350mA, well within the capacity of our 500mAh battery

 

then there is the performance issue every time you charge a battery it loses a bit of total storage capacity - yes it does, so does your phone battery. A use a lot of lithium polymer batteries (lipoly) and typically they can be recharges 150-250 times, probably more because model train use does not strain the battery the way model plane/car/truck does. A lot of my diesels can use NiMh batteries they can be recharged many hundreds of times, even over 1000!. Back to the lipoly batteries, I average 1 operating a week so a battery should last 3 to 5 years, so I need to budget about 3.3p per battery toward replacement cost, or about £43 per year or even less, especially with NiMh.

 

Then there is the problem of charging it and having to remember to do so - do you forget to charge your mobile phone? I recharge all the batteries used in a session after the session. I can charge 10 lipoly and 8 NiMh batteries at the same time. With typically 25 lipos used in a session recharging takes less than 2 hours spread over a few days

 

Also how do you charge - I charge off loco and have 4 lipo chargers and 2 NiMh. I don't have on/off switches either, just plug the battery into the harness before the session. My locos have easy to remove tender and diesel bodies. I can fit a battery set in a loco in less than one minute!

 

Increased efficiency of your locos - I found converting to battery power improved the loco haulage capacity. It is all down to the lack if power pickups My reading has Dapol class 20's having poor pulling power. my converted one lifts 20 coaches with ease!. Sigle bogie drive? no problem, I use Bullfrog Snot for traction and pulling loads of wagons

 

Batteries can be a viable power source for model railways, even with existing technology!

Hi David

 

For my purposes I have not seen any advantage of DCC over what I can achieve with DC but what you are using sounds wonderful.

[Roger Sunderland]

Hi David

 

For my purposes I have not seen any advantage of DCC over what I can achieve with DC but what you are using sounds wonderful.

Use what you feel most comfortable with is what I say. I do, however, cringe when you say there are no advantages of DCC overDC. You say you drive trains. Sorry but you dont. When you turn that knob you provide power to the track NOT the loco. Unless you provide isolating switches every 12 inches, or so, all locos in a power section will operate under DC not just the one you want. How is that prototypical.

 

Although you say you don't want them (plenty of people do ) permanently lit coaches, loco lights and idling loco sounds are all an advantage of DCC over DC.

[newbryford]

Hi David

 

For my purposes I have not seen any advantage of DCC over what I can achieve with DC

 

Bites tongue...…………

 

[Clive Mortimore]

Use what you feel most comfortable with is what I say. I do, however, cringe when you say there are no advantages of DCC overDC. You say you drive trains. Sorry but you dont. When you turn that knob you provide power to the track NOT the loco. Unless you provide isolating switches every 12 inches, or so, all locos in a power section will operate under DC not just the one you want. How is that prototypical.

 

Although you say you don't want them (plenty of people do ) permanently lit coaches, loco lights and idling loco sounds are all an advantage of DCC over DC.

Hi Roger

 

Where does the electricty come from to power a DCC fitted loco? Those two bits of metal under the locos wheels. No difference.

Where does the instruction come from to tell it to move? From the up and down buttons, slide thingy or twisty knob which the human operates with her or his fingers. No difference.

 

Where I need to isolate locomotives, or DMUs for operational purposes I use a cheap slide switch. Some of the my switches are now on the fourth layout. When I built Hanging Hill pre-DCC being the "in thing" I could achieve long lines of locos coupling to coupling (it would have been buffer to buffer had I removed the tension locks) I done so following experiments with isolating section lengths I did on Southbridge circa 1985.  When Hanging Hill was on the exhibition circuit I had a stock of over 300 locos, I could run them all on it. Had I converted to DCC how much would that have cost me? Please don't say I only needed to do those locos which were my favorites, I wanted to be able to run all my models which I did. 

 

I was using sound with Hanging Hill, nice under baseboard sound unit, the bass (missing off DCC sound fitted locos but ever present on idling Sulzer of English Electric lumps on the real thing) would travel across the exhibition hall and I would receive complaints form exhibitors and traders on the other side of the venue. So I stopped using it, before on board sound started to annoy fellow exhibitors. Not many layout owners seem to appreciate the guy on the stand next door might be a bit fed up by the afternoon of day two.  Anyhow sound is generally wasted on me because a diesel sounds like a diesel, with my limited ability to distinguish between tones a diesel engine sound is a diesel engine sound. I don't need it, if you do then good.

 

As for lights, I can remember pre-ETH fitted locos and air -con Mk2s in day time the lights were switched on by the guard when entering a tunnel and switched off when the coach he was in reached daylight again. And they were not very bright. Headcodes were the only front lights displayed in the period I model. Even if on in normal daylight the bulbs were not powerful enough to shine through the thick roller band. At night they illuminated the headocde but still didn't shine through. Rear red lights were used in some locations, the ER 25 KV EMUS used a red light not a tail lamp. Most places used a paraffin tail lamp. The flame shining through the red lens didn't show up in normal daylight so to save paraffin they were to only be lit in adverse weather or at night. While on the subject of lights, a mistake I made with Pig Lane and Hanging Hill was to have the yard lights on in the day time.  Pop outside and see if the street lights are on during the day, they are not and the railways like your local council don't waste money on electricity that is not needed so why do we modellers have our yard and station lights on when the model represents day time? 

 

I did try a night time running session using the lighting on Hanging Hill, after bumping into too many things in the manshed I gave up.

[Dungrange]

I was having a discussion with a chap who is implementing full automation on a reasonably complex and he was complaining that DCC isn't the 2 wires that he was told it was and that after almost 400m of wiring he was getting fed up with the DCC claims - I have some sympathy as my small layout has almost 200m of wiring (I know how many rolls of wire I have used ).

 

I asked who had told him that DCC was only 2 wires, he couldn't say and I wondered if there are other around labouring under this misapprehension that 2 wire are all that are needed - though I guess that in theory you could just have 2 wires to the track and then plug everything into the track and that would be the wire for the rest of the layout.

 

Has anyone else had this discussion about the mythical 2 wire layout - I agree that digital can dramatically reduce the wiring needed to achieve the same result in DC layouts, but in truth I don't think that what I am doing could be done in DC anyway therefore not a valid comparison.

 

Any thoughts?

 

I think that the DCC 'two wires' claim is technically correct in the context in which it was originally made, nearly three decades ago.  Take two yards of track, place three DCC fitted locomotives on said track and you can have independent control of all three locomotives with 'only two wires to the track'.  You can't do that with DC, where additional wire and section switches are required.  As such, the original claim is technically correct.  However, as the complexity of a layout increases, so does the need for additional wiring and that applies irrespective of whether or not the layout will be DC or DCC.  The problem is that some people seem to interpret the 'two wires to the track' claim as applying in all circumstances.  It doesn't - it just means that there will be less wiring compared to a DC layout of similar complexity.

 

Back in the 1990s, I was quite impressed by some of what DCC could do, but not enough to abandon DC.  Sure, DCC could cut the amount of wiring that would be required, but so what.  A few extra yards of wire and a few dozen section switches would be much cheaper than paying out £25+ for each locomotive decoder and £200+ for a new DCC command station.  Some things like Lenz ABC braking also looked good, but that was an additional cost.  For me, cost was a major barrier to entering the world of DCC in the 1990s and it remained that way for the next couple of decades.

 

Jump forward to 2018 and what I note is that the cost of entry to DCC hasn't really increased.  The price of decoders today's seem comparable with prices in the 1990s, yet the cost of everything else in this hobby has increased significantly.  Therefore the relative cost has reduced.  I finally bought my first DCC command station this year, not because of the 'two wires' claim, but because I want better control over lighting (ie no red lights on the rear end of the locomotive when it is coupled up to a rake of coaches / wagons and DCC sound.  To a certain extent, I've always seen DCC sound as a bit of a gimmick, but now that I have a DCC sound fitted unit, I think that driving to those sounds makes for a better driving experience.

 

However, I can see why many people don't see the benefits of DCC outweighing the cost.  It really depends on how much value anyone places on the benefits of DCC and that will vary by person and also by the type of layout that they have.

Edited August 13, 2018 by Dungrange

[Roger Sunderland]

Hi Roger

 

Where does the electricty come from to power a DCC fitted loco? Those two bits of metal under the locos wheels. No difference.

Where does the instruction come from to tell it to move? From the up and down buttons, slide thingy or twisty knob which the human operates with her or his fingers. No difference.

 

Where I need to isolate locomotives, or DMUs for operational purposes I use a cheap slide switch. Some of the my switches are now on the fourth layout.

 

As I said Clive, each to his own. However the "electricity" to power a DCC loco actually comes from the decoder which converts the permanent track voltage, around 18V AC to 12V DC, which the motor likes to run on. The same applies to instruction to move, the chip is interpreting "signals" from the controller and applying them to the motor. As an aside it can also apply EMF which enables no loss of power and of course inertia which enables controlled starts and braking.

 

As for your isolating switches and long line of locos I don't need any of those, or the associated wiring, and there is nothing to forget to turn on/off.

[Clive Mortimore]

 

As I said Clive, each to his own. However the "electricity" to power a DCC loco actually comes from the decoder which converts the permanent track voltage, around 18V AC to 12V DC, which the motor likes to run on. The same applies to instruction to move, the chip is interpreting "signals" from the controller and applying them to the motor. As an aside it can also apply EMF which enables no loss of power and of course inertia which enables controlled starts and braking.

 

As for your isolating switches and long line of locos I don't need any of those, or the associated wiring, and there is nothing to forget to turn on/o

No, the electricity to power the locos comes from the two bits of metal under the locos wheels, it might go through a electronic switch which is called a decoder but it comes from the track.

 

The instruction to move comes from the human hand on whatever box, controller, command module that "interfaces" the action of the hand with the wires going to the track on both systems.

 

I have been using EMF controllers since the mid 80s.

 

You might not need a set of cheap slide switches and their wiring but you do need an expensive electronic switch inside each loco.

 

I have helped on quite a few DCC layouts and I can honestly say that they all ran as badly as my DC layouts, and that is without operator error compounding things. 

 

 

Now what David is doing with his remote controlled locos is different.

[Andymsa]

Regardless of how any type of layout runs it being DC or DCC it can mostly be put down to build quality. As they say a good foundation gives a good end result.

 

Here's a thought, how many times have you been at an exhibition and the lovely train leaving comes to a grinding halt because some switch has not been set with DC. Using a computer does not mean automatic operation, I can run fully auto, semi auto or even manual. When manual the computer sets the route. There maybe those who like setting points and that is ok but with any human intervention that odd switch not being set is possible. Yes this is possible under DCC without a computer but the risk is reduced when using a computer. This is one of the benefits of DCC. That said if DC is your thing that's ok if Dcc is your thing that's also ok.

[newbryford]

 That said if DC is your thing that's ok if Dcc is your thing that's also ok.

 

Nearly four pages and it comes down to the above...………………….

 

[Vecchio]

It is interesting how a thread about two wires went into a fight between DC, DCC and radio control systems....

Let's enjoy our hobby, whatever the power system used is.

 

And working for the cable industry I am happy if you need more than 2 wires

 

Vecchio

(DCC since 2005 just to give you some food for arguments....)

[Roger Sunderland]

It is interesting how a thread about two wires went into a fight between DC, DCC and radio control systems....

Let's enjoy our hobby, whatever the power system used is.

 

And working for the cable industry I am happy if you need more than 2 wires

 

Vecchio

(DCC since 2005 just to give you some food for arguments....)

I agree which is why I said each to his own. Clearly some people have very fixed views though. A well built and wired layout in either DC or DCC will not run badly and I have seen plenty that run superbly.

[Butler Henderson]

One thing that DC is stuck with is the need for a control panel, certainly not necessary on many DCC systems and one of the big advantages IME of them.

[davetheroad]

One thing that DC is stuck with is the need for a control panel, certainly not necessary on many DCC systems and one of the big advantages IME of them.

 

Check out BlueRail at

 

 http://bluerailtrains.com/about-bluerail/

 

They have a video of a radio controlled board replacing the DC controller. I reckon you can do the same thing with my Deltang receivers. giving you DC control with a radio throttle. I think there will need for some protection circuitry added though. You can't have common return wiring either

[Clive Mortimore]

One thing that DC is stuck with is the need for a control panel, certainly not necessary on many DCC systems and one of the big advantages IME of them.

No you don't need a control panel for a DC layout.

 

 

One engine in steam, branch line terminus. Isulfrog points with a mechanical form of control. Two wires from the controller acting as a pair of bus wires, soldered to droppers at the feed positions. As it is only one engine in steam there is no need to have section switches, the section can stay live.

[Andymsa]

No you don't need a control panel for a DC layout.

 

Little Waltham station.png

 

One engine in steam, branch line terminus. Isulfrog points with a mechanical form of control. Two wires from the controller acting as a pair of bus wires, soldered to droppers at the feed positions. As it is only one engine in steam there is no need to have section switches, the section can stay live.

Ah a good candidate for two wires to the track with DCC Edited August 13, 2018 by Andymsa

[davetheroad]

No you don't need a control panel for a DC layout.

 

Little Waltham station.png

 

One engine in steam, branch line terminus. Isulfrog points with a mechanical form of control. Two wires from the controller acting as a pair of bus wires, soldered to droppers at the feed positions. As it is only one engine in steam there is no need to have section switches, the section can stay live.

 

Yep, that works just fine, I would go all sophisticated and have peco point motors but that means more wires

[Ravenser]

No you don't need a control panel for a DC layout.

 

Little Waltham station.png

 

One engine in steam, branch line terminus. Isulfrog points with a mechanical form of control. Two wires from the controller acting as a pair of bus wires, soldered to droppers at the feed positions. As it is only one engine in steam there is no need to have section switches, the section can stay live.

I'm not quite sure what we're proving here.

 

I have in the past built several "2 wire" DC layouts. That was because as a teenager I had no electrical knowledge , and DC connected to a single feed was all I dared attempt. Control panels seemed about as attainable as a trip to the moon

 

I can't recommend the practice. Flaxborough , my first modern image layout, ran very poorly, with serious voltage drop on the far side of the circuit and in sidings .The two versions of "Blacklade - the tramway" were better - the second, which had an isolating section (gasp!) at the far end of the return loop, plus a branch and a depot fan , could even run two trams simualtaneously. But dead-frog points are a serious liability unless your traction consists of bogie units with all wheel pick-up, and track layouts were severely constrained  by the need to avoid kick-backs

 

I am not a fan of the "hand of God" descending to throw points manually and I don't regret moving on to point motors one little bit . To be honest, contriving "wire in tube" control is probably worse than wiring point motors , and coping with the necessary projections beyond the baseboard throws up a further range of problems when building a portable, boxable layout (I can just see wire handles getting crushed as you box up)

 

The Boxfile - which is DC - has no control panel, just switches round the back. Not only are these vulnerable projections, getting at the switches to throw the points while operating is thoroughly inconvenient . I didn't think that one through in terms of ergonomics (And why I thought it would be a good idea to provide section switches I really don't know. They've never been used). Live frog points are strictly necessary when the fleet consists almost entirely of SWB 0-4-0s 

 

Tramlink , as built, is exactly 2 wire - plus a pair of home made chocolate block interboard jumpers. As and when I get enough other projects cleared out of the way , and can face excavating it from under the colliery tip of magazine back issues, it will acquire a couple of point motors and a few other refinements with a proper rewire. But the track plan is VERY simple

 

By contrast, Blacklade has no control panel - but full entrance/exit route control interlocked with working signals.  3-4 button presses and the whole route comes off. This uses the macro feature built into the NCE PowerCab - so the only cost is 2 x4-output decoders   I have operated a DC controlled Minories type layout , and my arrangement strips out 3 sets of common operator error - "Whoops, I forgot to set that section switch" , "Whoops, I forgot that point" and "Oh I forgot about the signal" . You can still choose the wrong route, or move the wrong train, but those are also DC errors ("Sorry, forgot to turn off that section"!)

 

Yes it's possible to build a DC layout with minimal wiring, using simple layouts , manual points and insulfrog. But the restrictions and problems imposed by doing that make it pretty unsatisfactory  

[Clive Mortimore]

I'm not quite sure what we're proving here.

 

 

Yes it's possible to build a DC layout with minimal wiring, using simple layouts , manual points and insulfrog. But the restrictions and problems imposed by doing that make it pretty unsatisfactory  

Simple, we were told that a DC layout needs a control panel. No it does not, and top the lot this plan can be only two wires. Limitations are a one engine in steam branch line terminus. Which I actually think would be great, how often do you see at shows and in the modelling press some sleepy branch line terminus with half of Top Shed's allocated locos on it when in reality only one train would be on the end section at a time. So self imposed operational limits, excellent.

 

Operator discipline is another subject all together, any DCC operator who says they have never made a mistake must be super human. 

 

Mechanical point control does not have to project over the baseboard edge.  Sadly not photographed was the point levers of my Southbridge layout, they sat inside one of the buildings at the back of the layout, within the baseboard edge.

[newbryford]

 

 

Operator discipline is another subject all together, any DCC operator who says they have never made a mistake must be super human. 

 

 

 

EFA

[Clive Mortimore]

EFA

Equestrian Federation of Australia :scratchhead: :scratchhead:

[Clive Mortimore]

EFA

Seriously I said DCC operator because Ravenser's post read as if us DC operators were not very well co-ordinated and kept making mistakes but if used a DCC hand set that wouldn't happen. I have messed up moves on Roundtree Sidings which uses a route setting DCC handset thingy, which I thought was very good.

[WIMorrison]

Now now girls - DC and DCC live together and provide different capabilities and different people are wedded to one or either for different reasons.

 

Personally I won’t ever go back to DC, but I can see the attraction for some people, especially those familiar with the technology and who for perfectly acceptable reasons don’t want to embrace the Digital world. A significant benefit being the costs, especially for a smaller layout as DC compared to DCC is significantly cheaper, DCC does come into own as the complexity and size increases excepting where a DC layout has developed over many years as the cost barrier to entry is very significant.

 

Plus the learning curve for people who are not Digital can be significant, I know as I am trying to help someone move from DC to DCC and they have difficulty accepting many of the concepts, but he does want to learn as he can see the benefits on a large, complex layout and feels that he needs DCC to progress further

[newbryford]

Equestrian Federation of Australia :scratchhead: :scratchhead:

 

Edited for accuracy

[43110andyb]

As I'm currently involved in re-wiring two layouts that are 20 years and 30 years old (one to DCC and the other a DC re-wire) I can confirm that neither are 2 wires!!!

The DCC layout (Charwelton to DCC) has over 700 individual track feeds in the fiddle yard alone going to 2 separate bus-bars, the front will have 3 bus-bars when completed.

Enjoying both re-wires equally with my personal preference DCC after several years assisting exhibiting Thorne yard and various other projects.

 

-Andy.

[Ravenser]

Seriously I said DCC operator because Ravenser's post read as if us DC operators were not very well co-ordinated and kept making mistakes but if used a DCC hand set that wouldn't happen. I have messed up moves on Roundtree Sidings which uses a route setting DCC handset thingy, which I thought was very good.

 

People make mistakes - but the advantage of what I've done , using a feature that was built into the handset, and therefore came free - is that it designs out 3 major categories of operator error that I and others committed on a similar type of layout run with DC.

 

You can't "part-set" a route. You don't have to puzzle out which points you need to change - with every chance of making a mistake. Check the card, key in the number - the lot comes off.

 

Operator error does happen under DCC - a frequent cause is when I've been talking to someone at a show (the layout is front operated) and move a train forgetting I haven't set up the route yet. That would be an equal - if not greater - problem with DC

 

(Yes large layouts can use a computer "glass panel". But - I've seen a software glass panel for a medium-size and complex layout completely rebuilt from scratch in 6 hours . Try rebuilding a hardwired panel in that kind of time! And pretty well everyone is capable of plugging in a USB cable - very different to figuring out the connections flor a hardwired panel)

 

I'm sure it's technically possible to implement entrance/exit route control on a DC layout (eg the Southern Region at 305mm/ft scale). But the circuitry involved in doing that is out of the league of 99+% of modellers. Anyone with an NCE system can do what I've done with an hour or two's work (I suspect some other systems have similar facilities- I  have a feeling Digitrax may have something programmable through the decoders)

 

While yes it's possible to have 2 wire DC layouts without control panels, in practice it can only be done with the sort of layouts featured on the late Carl Arendt's website or their slightly larger cousins. I've built enough of that kind of layout to be acutely aware of the limitations they impose.

 

If you want to go beyond that and you want the layout to work better than "after a fashion" then the wiring required for DC control will be significantly more complex. And 90% of people will want to go beyond "micros" and one engine in steam

 

I'm honestly not persuaded by "wire in a tube" control - and very few others in the hobby seem to be. Modratec lever frames may look impressive but they aren't cheap and DCC accessory decoders will work out cheaper per output. Apart from that, the only commercially products seem to be the Mercontrol system, which dates back to the dawn of time (or at least the 1950s and possibly pre-war), and someone's "Blue " system which seemed to cost nearly as much per point as a Tortoise.  Large wooden knobs sticking out of fascias are a real issue if you want the boards to box up as a crate or sit side by side in the car

Edited August 14, 2018 by Ravenser