Should/could I get rid of the third rail?

@Robbin posted:

I was able to examine an M1(A or B) up close and noticed that driver 2 and 3 of 4 do not have flanges.  Silly me.  I figured that this was just a feature of my model engine and never dreamed that the real thing also might have to negotiate sharp curves and would not want all the drivers flanged (see photo).  Just for reference the K-4 does have all three flanged but it seems that the four (and assume five driver engines) it might depend on the wheel base of the drivers.  So this definitely clears the way in my mind to having as sharp as O96 or 48" radius curves and two rail engines like an M1 and J1 that I would assume also dont have to have all the drivers flanged!  Just like the real thing.

I only own two 2R Steam engines and all drivers are flanged (Pacific and Niagara 4-8-4).  I understand your excitement.  Before making the assumption that the 2R models follow the prototypes, I think it would be worth checking with 2R guys if that is the case.  Hopefully they post to this topic, but if they don't you may want to start a topic on that.

As always it is worth to check prototype photos if that interests you.  Many larger steam locomotives did indeed have flangeless drivers.  What drivers were flangeless varies by road and locomotive type. 

Here are observations from my own layout

36" Radius (this is my minium, a lot of these can go around narrower)

MTH 2-10-0 consolidation

Sunset GP7  (fixed pilots)

Sunset GP9 (fixed pilots)

Sunset SD9 (Fixed pilots, six axle)

MTH F7 ABBA  (Fixed pilots, Factory Spacing)

Atlas RSD7 (Fixed pilots, six axle)

MT Train Master (fixed pilots)

Weaver RSD 12 (Fixed pilots, six axle)

Atlas RS1 (fixed pilots)

MTH Aerotrain (Fixed pilot, prototypically close coupling locos and all coaches, converted to 2 rail)

All GGD 21" passenger cars  (Factory Spacing)

MTH GG1 (converted to 2 rail)

40" Radius

MTH F7 ABBA (Prototypical close coupling)

Lionel ABBA Sharks (fixed pilots, prototypically close coupling, converted to 2 rail)

MTH L1 (2-8-2)

46" Radius

Sunset GG1 (widened slots in four wheel trucks)

MTH P5a and P5a Modified (Fixed pilots, converted to 2 rail)

All GGD 21" passenger cars (prototytpical close coupling, diaphragms touching)

Sunset M1b (4-8-2).   Center drivers blind

Sunset B70m baggage car

MTH I1 (center divers are blind from the factory)

Sunset N1 (2-10-2)

All of the above curves are hidden for asthetic reasons.   Which means equipment has to be super reliable

All of the above curves have easements

One more note: Awhile back I had a Westside J1a (2-10-4). A massive locomotive that had been reworked by Ed Rappe to go around tighter radius curves.  I set up a test track, and with easements it could easily go around 44" radius curves,  going forward and backwards. It looked a bit silly with all that overhang, but that had nothing to do with the number of rails.  Or its ability to track the 44" curves

I left the center rail a few years ago, never looked back.  Found along the way many “beliefs” of 2R were not necessarily true.  

Most of all, my modeling focus changed and 2R is where I want to be.  Haven’t regretted it.  

PRR steam locomotive practice with regard to blind center drivers varied widely by class.  J1 and J1a 2-10-4's were fully flanged. PRR I1 2-10-0's were built with 3 blind center drivers, but in the 1930's flanged tires were fitted to drivers 2 and 4.  H6sb 2-8-0's had blind center drivers, while H8 ,9, and 10 2-8-0's had fully flanged drivers.  That said you'll find many classes of previously imported PRR  O scale 2 rail locomotives can with minor adjustment (like drawbar lengh) can negotiate 48" radius curves.  When in doubt about a specific model I recommend posting a question on the 2 rail forum asking about other's experience with the model.   

Thanks Ed,

any idea how they made the decision and what the trades were on which engines got blind drivers?  I was not aware of any of this and this is the sort of thing that I find interesting.

@Robbin You might like some of this...

https://cs.trains.com/trn/f/741/t/162184.aspx

Even switchers such as Pennsy's 0-6-0's sometimes had a blind center driver, as well to help negotiate tight curved trackage.

Tom

Nice!  Seems like I have read you kind find a prototype/example for everything.

2 or 3 rail there is a lot to say for battery power especially since you are starting your layout

no track wiring- this is a big amount of effort saved

no track power transformers (you can simply use regulated inexpensive dc power supplies for building lights and accessories)

no track cleaning

this also opens up more options for control systems (for sure more than 3 rail)

I wanted again to say how much I appreciate everyone who has posted taking time to share information here!  I am still re-reading the posts and digesting while doing research.  I was noticing upon reading the posts again that in the post John Sethian put in that there were converted 3 rail to 2 rail engines listed.  Would anyone that has done this point me to information about what that would look like?  What I mean is, what is involved in converting a center rail lionel or mth to two rail?  It would be nice to have a two rail digital control conversion option for the fleet of engines I have.  But I did not even know that conversion to two rail was possible.

Robbin

Are you asking about are you asking about the control systems for running 2 rail locomotives?  Or about converting 3 rail locomotives and equipment to run on 2 rail track? 

If its the former, all control systems work equally well for 2 rail or 3 rail locomotives.  For example, I run both DCS and TMCC/Legacy on my 2 rail layout.

If its the latter, send me your e-mail and I will send you a copy of a talk I gave on converting 3 rail equipment to 2 rail.  My e-mail address is in my profile

@Robbin posted:

I wanted again to say how much I appreciate everyone who has posted taking time to share information here!  I am still re-reading the posts and digesting while doing research.  I was noticing upon reading the posts again that in the post John Sethian put in that there were converted 3 rail to 2 rail engines listed.  Would anyone that has done this point me to information about what that would look like?  What I mean is, what is involved in converting a center rail lionel or mth to two rail?  It would be nice to have a two rail digital control conversion option for the fleet of engines I have.  But I did not even know that conversion to two rail was possible.

The conversion of 3 Rail Steam Engines to 2 Rail can be done, but if you don't have Machine Tools it is not simple or inexpensive.

The "problem" is 3 Rail equipment is it designed to pick-up the current from both outside rails and the chassis is "live".  The center roller is insulated from the chassis and sends power to the input of the board or reversing unit.

2 Rail equipment has the wheels on one side insulated, in most cases a "wiper" is used to pick-up the current from those wheels.

Remember that the vast majority of 3R equipment including rolling stock has metal wheels and axles.  If any of this equipment, or the wheels on the tender or pilot trucks on a steam engine are not insulated on one side (which is almost always true of 3R), they will create a dead short on the layout.

That is what has driven me to the conclusion that if I want to go from 3R to 2R it will be via Dead Rail.

Hope this helps?

I was in the middle of trying to figure all of this stuff out myself, and the decision I had made was to go with Blunami and battery power and 2-rail track and Kadee style couplers, but with 3 rail wheel flanges on everything, both steam and diesel. Luckily my rolling stock collection was fairly small, so it wasn’t overwhelming to convert everything.

Initial testing showed promise using hand laid 2-rail, code 148 track and turnouts (clearanced for deep flanges), but then I got sidetracked by O scale and 1:24 trolley and interurban kits and scratchbuilding, which has become an all-consuming passion.

Right now anything that isn’t a trolley or interurban is either sold or in the process of being for sale so I’ll probably never know how well my O scale 2-rail deepflanged layout would have worked…

Jeff C

Thanks for the replies!  To be clear, I dont know what I am asking exactly.  I would like to know what options are available if I convert to 2 rail.  I am making trades prior to starting a layout in NC probably within a year.  I have about a dozen three rail mostly tmcc large steam and a few mixed 3d Rail, MTH, Williams(with err Cruise) diesel and overhead electric.  I like the engines (admit I have too many for the size of my layout) but would like to keep them if that makes sense.  I am used to scale HO layouts so it is appealing to think of running two rail O scale, multilevel in NC.  Even though I have only a 1&1/2 car loft to fit it in (gulp!).  I need to make trade offs but would like to understand the trade offs.

I dont rule out dead rail as the amount of time I am spending prewiring Ross switches, running wires on my basement layout here is significant.  Sure I have bought some fun switches for the Ross switch controls (see attached) but I can see where it would be nice not to count on the rail for electricity for the engines.  The passenger cars would be a complication (I loosely have the trains from Washington DC union station from the fifities, Pennsy, B&O, Southern etc).  No freight yet.

Would like to understand the options to have the best shot at making the new layout enjoyable as possible the first time out.  My time in O scale has been fairly limited (about 3-4 years) and my hobby time is very limited.  But I definitely want to stay in O scale.  Thanks!