Does 2-RAIL Atlas Rolling Stock Have Problems On 3-RAIL Track ?

Two rail "O" trucks with small profile flanges will not run well on tubular 3 rail track, or through 3-rail turnouts/switches/crossings due to improper flange clearances.

Bill in FtL

Atlas O two rail will run on Atlas I three rail but turnouts must be crossed slowly.

Scrappy

2 rail flanges are much smaller than 3 rail.    They will run pretty well on 3 rail track IF it is in gauge and has flat top rail.    As mentioned above, you have to be careful on switches and crossovers.      The gaps at frogs and the guard rails are wider than on 2 rail switches.     

I ran 2 rail cars on Gargraves track in the late 70s.   Their track at the time had a nice flat top profile.    I did have to add filler pieces on the guard rails on some switches.   

As for speeds, I never made any adjustments.   I ran at typical 2-rail speeds which tend to be slower than 3 rail.

Just dont back up 

I've been doing it for years now at the club. Most 2-rail cars don't have a problem with the club's Gargraves and Atlas track with Ross turnouts. There are some caveats, though:

• Your turnouts need to be numbered turnouts (11-degree/#5) as the frog is straight and the gap isn't as large as a #6 or #8. Curve-replacement turnouts like O-72 will likely cause issues at speed or when backing.
• Insulated rail signal triggering won't work with scale-wheeled cars due to the insulated axles. The work-around for that is a caboose or last car with non-insulated axles.
• Body-mounted couplers introduce a requirement for more careful placement in the train. Long cars should not be coupled to very short ones because the trucks are set further in on longer cars and the end swings out from the center of the track more than on a shorter car.
• The weight of cars at the front of the train can become more critical to prevent string-lining because you're dealing with smaller flanges.

In the video below, the locomotives all have scale flanges and the cars are a mix of hi-rail and scale (the transition cars have scale wheels and coupler on one end).

Hey Matt, that's a good looking train. Are the locomotives MTH? 

I've given up trying to run 2 rail stock through my Ross track and switches. Even after shimming the switches, and keeping the 2 rail stuff at the rear, derailment occur as often as not. It just got frustrating.

My 2 rail stuff is confined to a closed loop with no switches, min. radius O-80. No problems there. Even there though, I keep the 2 rail stuff at the rear of a train to minimize possible trouble.

Hudson J1e posted:

Hey Matt, that's a good looking train. Are the locomotives MTH? 

Thanks, Yes, they're MTH. Scale-wheeled C40-8W's. All three powered.

Same here Terry, been there done that. Derailments are just not acceptable.... on any railroad.

Matt we refer to that as the "long-short" rule and many cars have to be set out to comply with that rule, especially on the Diego's