I've been doing some reading on the subject of whether or not the whole DCC-friendly/DCC unfriendly facet of Walthers/Shinohara track is a myth or fact, and I'm somewhat confused.
Fact is, I have many Shinohara turnouts that were given to me a few years back from a friend who had to liquidate of a lot of his trackage due to space limitations. The turnouts that he gave me are beautiful #8 Code 83's, however are obviously power-routing turnouts. I see that Walthers is now selling the 'DCC-Friendly' version of the same turnout with some obvious modifications which led me to believe that I might need to purchase the DCC-friendly track (as I'm going DCC on the layout yet to be built)...until I started reading back and forth articles on the subject. One article even suggested that the whole DCC-friendly concept is merely a myth and is simply a fancy marketing tactic. Another suggests that someone has used 'DCC-unfriendly' non insulated frog turnouts on their layout with absolutely no problems at all, and without making any modifications to the turnout itself.
So, I guess the lingering question for me is: Is there truth to the fact that the whole 'DCC -Friendly' concept is a myth?
Will these turnouts that I now own work on a DCC wired layout, and will they work well with a good solid wiring job without making modifications to the rails?
Speaking of turnouts in general, but equally applicable to specific brands, the whole, "DCC Friendly/Unfriendly," concept is a misnomer!
There are two kinds of turnouts, power routing and dead frog/live rails. The latter are called "DCC friendly," in that you can run right in from the heel end, split the points and set yourself up for a head-on collision with the train you were supposed to stay in the siding for, assuming that you don't derail the locomotive and make a mess far bigger than simply re-setting a circuit breaker. (This is, "Friendly???")
To use power routing or live frog turnouts, all you have to do is gap the rails at the heel end of the frog and route power to the frog and closure rails through contacts, either on a switch machine (most already have, or can be fitted with, contacts) or on an electrical switch which is part of the point-moving mechanism. Depending on the points to carry power to the frog is not a good idea.
As long as the engineer is awake and paying attention, a power-routing turnout is just as friendly as a dead frog/live rail turnout. The only advantage that the latter has is that if the engineer is inattentive the DCC circuit breaker will not trip and prevent derailment at a turnout thrown to the opposite route (or that head-on a little farther down the line.) As for me, I'd rather have to reset a breaker, thank you.
Chuck (modeling Central Japan in September, 1964)
I'm in the camp that says DCC Friendly is only advertising hype in an attempt to convince the gullible that they need to purchase all new turnouts when they change from DC to DCC operation. If you have the layout constructed and wired correctly for DC operation, it will work just fine in DCC mode without having to change any of your trackwork.
The 'DCC Friendly' concept was to reduce the chance of a short if an engine derails on the turnout. With the 'live frog' type of turnouts(like the original Walthers/Shinohara) it was very easy to produce a 'short' from the stock rail to the points. With DC, this would only affect the train that was derailed(one power pack, one train...).
With DCC, you have some serious power running through the rails(even with you throttle turned down). Typical DCC systems have anywhere from 2.5 amps - 10 amps available to the track. A short like above will shut down the entire railroad if there is no 'power districts' to keep only the derailment site shut down. Long wheelbase brass steamers sometimes 'touch' the inside of the points as well and short out. You might even 'tack weld' your engine to the rails!
The above said, 'DCC Friendly' just reduces the chance of a short happening. Myself, I have no problem using 'live rail' turnouts - But I have power districts to protect each of my towns/sections of the layout(8 total). Some LHS's and 'experts' will tell you you need DCC turnouts for a DCC layout(the same folks have also said that DCC is so simple, you just hook 2 wires to the rails and you are done...). The bottom line is with DCC you need to use larger gauge bus wire, and you should really break down the layout into power districts(at least anything bigger than the typical 4x8) - Just to make trouble shooting a whole lot easier.
Jim
Modeling BNSF and Milwaukee Road in SW Wisconsin
NevinW wrote:I don't think it is a myth. I have seen problems with momentary shorts with some the old Shinohara turnouts on some layouts. Other layouts seem to have less problems. I would recommend reading http://www.wiringfordcc.com about the differences. It is certainly possible to use older turnouts without problems- there seems to be a number of factors that determine how much of a problem it is going to be. Modifying older turnouts to be less of a problem is described at that website. It certainly isn't a marketing scam. - Nevin
The 'modification' needed to prevent point-back shorting of long-wheelbase locos is a dab of clear nail polish on the outside of the point. If you don't have a nail polish user in residence, any clear lacquer will do.
On my hand-laid turnouts, I went for a more thorough solution. The points pivot around nails dropped into drilled holes at their heels, my throwbar is insulated and the open point has no electrical connection to anything - and thus, no way to cause a short.
Andy Sperandeo MODEL RAILROADER Magazine
Sorry for the long reply....I would agree that the idea of DCC friendly turnouts are in fact another name for bullet proof switch wiring that has its roots in the DC days. The idea that a layout that operates well in DC, will operate well in DCC is pretty accurate. I have seen several conversions of older, well operating layouts to DCC with very few problems. The only exception can be the issue described in section 1. below.
Shorts in DCC and DC are different. DC can tolerate a small, quick short with little effect on the locos running on the layout. In DCC due to the large amount of power on the rails, momentary shorts trip the circuit breaker which then kills power to the section of the layout that is powered by that breaker. On some layouts it will stop the whole layout if there are no power districts. There is usually a reset time (a few seconds) and then everything powers up again. When this happens a lot, it can be very annoying. Joe Fugate has lot of info in various threads on this forum about short management and ways to manage this issue..
There are several issues that come up with switch wiring:
1. Points and closure rail polarity: The old shinohara design has the points and the closure rails all the same polarity depending on which way the switch is thrown. This can cause a short if the backs of the wheels of loco or car (metal wheelsets) bridge the gap between the points and the stock rail of the opposite polarity. In DC no problem with this momentary short, in DCC could be a show stopper due to the sensitivity of the circuit breaker.
There are two fixes here that are employed by DCC friendly turnouts. One is to insulate the points from each other so they are not the same polarity and the second is to hard wire the closure rails to their respective stock rails so they are always the same polarity all the way to and including the point rail. You must isolate them from the frog to do this.
2. Dead frogs versus live frogs: Many DCC friendly turnouts isolate the frog and leave it dead or leave you the option to power it by soldering a wire to it and running it out to an external switch of some type. The power routing turnout was supposed to save the modeler the trouble of setting up this external switch by powering the frog and closure rails through the point contact on the stock rails with the added bonus of changing the polarity automatically. This arrangement is notoriously unreliable over time and generally fools the modeler into thinking there is no problem because it runs well when new. As the layout ages and especially after ballasting, the points begin to lose contact. This leaves the points, closure rails and the frog dead and will stall a loco running through the switch. Then the points cleaning process begins......To be avoided if possible and is a drawback to power routing switch design.
Many modelers with diesels or large steam can get away with unpowered frogs. Those who want to run smaller wheel based locos, small brass etc. will have problems with stalling on a dead frog, particularly in large radius curves where the frog is long. Therefore the frog must be powered. There is a catch here as the polarity must be changed with the points to avoid a short. There are lots of ways to do this. Pick the one that works best for you.
There are some modelers who opt for dead frogs so that an engineer who is running though the switch thrown against his train won't cause a short. This is a judgment call. I personally haven't found a need for this.
Most of what I have described above is true for switch wiring in DC as well as DCC. As one might expect there are lots of opinions on this and there are several different switch wiring schemes. Personally, I opt for super reliability and I power the frog, and Isolate the points and hardwire the closure rails. I buy DCC friendly when buying new stuff, not because it is DCC friendly, but because it is more robust switch wiring. I took the time to modify my old shinoharas. It was time well spent.
One of the difficulties with all this is that it is easier to make switch wiring modifications when the switch is on the bench than later when it is on the layout. I have had to go back and retrofit stuff after installation and ballasting and it isn't fun. So do you spend extra time in the beginning to do certain modifications or do you wait to see how well it runs? I have my answer, many others opt for different solutions.
Take the time to learn switch wiring thoroughly and then ask some other modelers in your area how their stuff is working. Go run on some layouts and see for yourself. I find that the idea of "runs good" is somewhat subjective. I think you will get a pretty good idea of how you want to proceed.
Your mileage may vary,
Guy
see stuff at: the Willoughby Line Site
Unlike Andy Sperandeo, most of my DCC and turnouts bad experiences have been with shorts at the frog end of the turnout. And contrary to MR's head-in-the-sand approach to this issue, I find the term DCC friendly turnout to be very useful.
A DCC friendly turnout is simply a turnout that has less chance of causing a short.
I discuss this whole topic more in my post titled DCC friendly turnouts made simple.
Turnouts can have more shorts if the points/closure rails are not the same polarity as the stock rails, and they can have more shorts if they use a live powered frog. It is *very valuable* on a DCC layout to reduce the possibility of shorts. The MR staff should know this, so frankly I'm puzzled as to why they pretend like the whole DCC friendly turnout issue doesn't exist.
MAKING TURNOUTS LESS SHORT-PRONE
Dead frog turnouts will result in less shorts if someone happens to enter the turnout from the frog end and the points are thrown against them.
A DCC-friendly turnout has the points and closure rails be the same polarity as the stock rails, and it has an isolated frog so you can leave the frog dead if you like. If something happens to derail on a DCC friendly turnout, there is less likelihood of a short.
And shorts on a DCC layout are generally considered BAD, because they can shut down much or all of the railroad unless you have specifically wired the layout to have robust short management.
Joe Fugate Modeling the 1980s SP Siskiyou Line in southern Oregon
From the far, far reaches of the wild, wild west I am: rtpoteet