2 rail? or 3 rail

[wsdimenna]

 Two big items:

space... It is very difficult to do any sort of prototypical operations unless you have lots of it compared to 3 rail. That was the issue here.   Although main is easily done in 072 min (072-099). The yard operations use 054.  For track spacing in yard the 072 switch leaves a spacing for yard that is too wide IMO. So either it was 054 or the very long #5 (Atlas). 

Higher cost of rolling stock, limited quantities, although getting better.  Extra cost to change 3 rail rolling stock to 2 rail.  MTH 3/2 engines  have equalized the cost of three rail two rail engines

With command control wiring isn't the issue it used to be.

 

Bill D

 

 

[lionelsoni]

I've never heard of "polarity feedback", and I don't see any danger in using a common return for AC and DC supplies.  In any case, even with a common return, it seems to me that two poles are needed.

[phillyreading]

There might be advantages to either two or three rail but you can run both two and three rail trains on GarGraves track with the use of a couple of double pole double throw toggle switches that will send power to whatever rails you want power sent to. The reason I suggest double pole switches is to keep the A.C. and D.C. power seperated from each other. Some people will say that you can use single pole switches but then there is always a slight chance of polarity feedback with A.C. to the D.C. power supply and thereby blowing the diode circuit in your D.C. power supply or worse harming your two rail engine.

Lee F.

[3railguy]

2 rail is much more feasible today than it was 10, 20 years ago in regards to cost and availability. Space constraints are the biggest factor. You need at least 36" radius (72" dia) curves if you plan to run 4 axle diesels and 40 ft freight cars, 48" radius (96" dia) curves if you plan to run 6 axle diesels and small steam, or 60" (120" dia) radius curves for practically anything.

The pros and cons as far as wiring issues are concerned are about a horse apiece. 2 rail DC engines can be reversed simply by reversing the polarity with a reversing switch at the control panel. It is much easier to do locomotive lash ups with 2 rail DC as all engines run in the same direction depending on polarity fed to the track (and of course if the motors are wired correctly within the engine). Command control has taken care of 3 rail lash ups but at a price. The explosion of inexpensive electronic modules have made signaling much easier with 2 rail. 2 rail command control can be done with DCC. Some are using TMCC 2 rail AC.

As posted above, many MTH engines can run on 2 or 3 rail. Their current 3 rail freight cars can be easily converted to 2 rail as they have Kadee coupler mounting pads cast into the under frames.

Atlas Trainman has made 2 rail very affordable. Conventional diesels can be had for under $200 and freight cars for around $35.

When dealers sell off new old stock, much of it is 2 rail and you can get some pretty good deals. Especially with brass clearance sales. The 3 rail models sell out quickly in comparison.

If you were to sell and buy on the secondary market, It is much easier to sell off  3 rail and buy into 2 rail than the other way around as 3 rail is more in demand. You can come out further ahead if you are patient.

There is also a boat load of O scale 2 rail vintage rolling stock kits on the secondary market at some pretty incredible prices. Kit building is not as popular today and dealers are practically giving them away to get rid of them.

The industry has seen an explosion of O scale building kits and built ups at very attractive prices in recent years. They look just as good on a 2 rail layout as the do 3 rail. and you are off to a good start there.

Lastly, with 2 rail, you don't need to worry about hiding the 3rd rail if realism is a concern for the obvious reason.

There are pros and cons to everything. Personally, if I had the space, I would be doing 2 rail for the realism and the availability of great looking equipment at great prices.

 

[dougdagrump]

Generally speaking 2rail is usually associated with "modeling" and 3rail as "toys", however you will find a lot of 3rail layouts that are equal to 2rail in their modeling abilities. Another brand for consideration would be Atlas, my personal preference, which we have had on the club's layout withstanding 5+ years of use 6+ days a week.

The deciding factor between 2 or 3 rail should really be based on what you like and what you want your layout to reflect. You will find that 3rail is simpler to set up and wire, electrically speaking, you will find a much larger selection of motive power and rolling stock and the prices of of the 3rail is a little cheaper than 2rail.

Before your final decision be sure to do your research and visit any clubs or hobby shops that may be in your area. Haven't checked your bio but be sure to add a general local, there may be another forum member here that can be off help as well.

[challenger3980]

How much equipment do you have? and what kind is it? MTH makes some locomotives that are 2/3 rail convertable, I think that Atlas O may also offer some convertable locomotives. The vast majority of 3 rail locomotives would not be practical to convert from 3 rail to 2 rail. With 3 rail equipment the wheels are not insulated from the axles, and will conduct from outside rail to outside rail, which are both common return, sometimes refered to as  ground, which isn't exactly correct. I'll let Lionelsoni (Bob Nelson ) explain this one. While there are always exceptions generally 3 rail uses AC power, and 2 rail uses DC power (except S scale uses a lot of AC/2 rail) with 2 rail one rail provides one polarity and the other rail the opposite polarity. Because of this, 2 rail wheel sets need to insulated from side to side. 2 rail cars can be used on 3 rail, but the uninsulated wheels of 3 rail will cause short circuits when used with 2 rail. Plus, again generally speaking, 2 rail and 3 rail, usually use different types of couplers.

  If you have a bunch of 3 rail, it is best to  either stick with it, or sell it all, and buy 2 rail equipment. They are not intercompatible on the same tracks. your other option would be to build a layout with both 2 rail and 3 rail track, and run your equipment on the appropriate tracks, and accept that some of your equipment will never run on certain portions of your trackage.

Doug

[ChiefEagles]

paboiler

Or am I just asking for trouble going with 2 rail.  I am relatively new to model railroading, but I can usually figure things out OK.

You asked for an opinion.  Each his own.  Maybe you will get some more posters.  Also, keep on asking questions.  No question is too small or too "stupid".   

[paboiler]

 I am upgrading (?) from Fastrack to gargrave or ross track (3 rail) for a permanent layout and was going to use whichever one was easier to obtain from a local hobby shop.  However, during my research, I am seeing alot about 2 rail.  Should this be an option, (currently I don't have alot invested in the fastrack layout)?  Or am I just asking for trouble going with 2 rail.  I am relatively new to model railroading, but I can usually figure things out OK.