My! this has been an interesting and long discussion of 3 vs 2 rail. I am 86 and can remember back when model railroaders laid their own track and switches. Way back then, there was no ready track unless you went with Lionel, Marklin, American Flyer or Marx. Everything was hand laid track; even the ties had to be hand cut for use. I remember a childhood friend of mine had a Marklin train using the old style raised 3rd rail. At the time, I was just getting into 2 rail HO, My friend's Marklin train was always running without problems while my 2 rail trains wouldn't run reliably. O scale (non Lionel) used outside 3rd rail which was very reliable, though not very prototype. Steam locomotives with an outside 3rd rail pickup wasn't proto, but one didn't really notice. The pickups were a piece of wire spring rubbing on the 3rd rail. There were models of electric locomotives with the same outside 3rd rail that was more true to prototype. In the U.S. there was the outside 3rd rail system used mostly in the large cities and subway systems and the overhead wire system used on the interurban systems between cities. These were extensions of the transcontinental steam rail lines. Railroads like the Milwaukee, Northern and Virginian used overhead wire on their long routes. The use of electricity was chosen due to the cost and availability of electric power. When diesels came along, everything changed with the demise of steam and long distance wire. As Americans, we naturally took up 2 rail as we rejected any 3 rail models which were called "tinplate" and considered toys for around the Christmas tree. As for the popularity of 2 rail over 3 rail, serious modelers as opposed to children, wanted to be considered "serious" model railroaders. Even today, Marklin is still considered "tinplate", but has it's following, I for one being a long time 2 railer, have switched over to 3 rail. Today's 2 rail is completely changed from the way it was 80 years ago. Much less emphasis today is placed on building models, either from kits or scratch built. Instead it consists mostly of "toss it up in the air and it comes down full assembled and ready to run". As a result , craftsmanship has lessened in favor of the ready-to-run train system. I guess people now-a-days don't have enough free time to devote to model building. IT's only the old guys, like myself who still have the time (although diminishing) and patience to build. Due to age, I have switched to 3 rail so I can get a layout up and running quickly. I do like the European prototype models and being American, that really doesn't bother me. It's MY railroad and I can run it any way I want. I may run American cars with German locomotives. I would also like to point out; 3rail doesn't lend itself to hand laid track methods. When you use Marklin track sections, what you get is it; not much you can do. When you use 3 rail track, you are committed to the 3 rail system. 2 rail systems allow you to design track in ways that can't be done with 3 rail. Personally, I like the realism of 2 rail track and it's cars and locos. It has come a long way up from the Strombecker wood locomotive to the present magnificent models. Again, for us old timers, DCC leaves us out in the cold (can't teach an old dog new tricks). I'm not sure if I have answered the OT at all, but would like to contribute to the discussion anyway I can.

Actually overhead catenary with DC was a relatively easy way to avoid the problems with 2 rail DC. When using a catenary, the + was always the catenary and the - was always one (or both rails). When a locomotive would run on a reverse loop with both tracks used for -, there was never an issue with a short. When the tracks were separated into + and -, it created a short when the loop closed.

This enabled many modellers to run 3 rail AC models using the track and the centre rail and to run 2 rail DC models using the track and the catenary on the same layout.

Regards

Mike C

What issues?
I have no problem by use two rail polarity by use reverse-loop digital modul.

Hello Good morning

I think the 3-lane system is the best. We all know its advantages.

But I think it has two problems, although these only affect a very small part of the fans.

The first is that if you want to make a very realistic layout with very large radius turnouts, you have the problem that it is very difficult to get the current collector slider over the rails on a very slender turnout.

The second problem, which only affects heavy use layouts, for example MiWuLa or Merklingen, is that the pukos wear out due to the friction of the sliders and disappear, in the two mentioned installations, they started with K-track, and now they have changed to the 2-rail system.

Best regards

As for me, the choice was very clear. We, my brothers and I, grew up in the late 50s/early 60s. Dad had American Flyer and Lionel trains. At around

7 or 8, I got the Tyco DC HO set "General", Civil War era train. It was ALWAYs derailing and never ran right, in spite of dad making me a board layout with

tracks tacked down. I lost interest. Then, one Christmas back then, I saw the fantastic, huge Märklin show layout at FAO Schwartz in Manhattan and I was hooked with

Märklin then and never looked back. The multi-train operation with signals just blew me away! Cheers from Peter.

"pukos wear out due to the friction of the sliders and disappear,"


I have never heard this before.
Would that happen on any other layout than MiWuLa?
(1000s of hours of use)

Has anyone every had this happen? I know if you lean on or push down the pukos by accident then yes, it will have contact issues... but "wear out due to friction of the sliders" I highly doubt any normal layout would wear out. Please correct me if I presume. Its seems the sliders wear out first. Does K track wear out sliders more quickly is another question? I don't know.

The Miniatur-Wunderland website explains:

"The Roco Line track is used in our Hamburg, Scandinavia and Italy sections. Why did we use Roco and not Märklin? Because there is much more rolling stock available for two-line track, so we were spared having to convert the material. As tram track or in the harbour area, the two-rail track is generally excellent because you can also lay road paving between the rails without interference."

Source (German): https://www.miniatur-wun...modellbahn/gleissysteme/

After so many hours you say. My C track is still fine after years of use. You do need to clean the rails after some hours of use which helps with slider contact. Never heard of Pukos disappearing.

I once saw a Märklin layout in a museum. There was no more traffic on the loops with slim turnouts because the Pukos had become so short that locos would always short-circuit the layout.
There still was traffic on the industrial area with regular turnouts (where rails near the frogs are insulated).

Not an everyday problem for private layouts, but It can happen on layouts other than MiWuLa, too.