dumb question....

That engine is "Proto-Scale 3-2 3-Rail/2-Rail Conversion Capable", according to the MTH data. It should have the pickup rollers in the box, which you can install and set a switch underneath to 3-rail operation and it will run on 3-rail track and AC power.  It may have trouble negotiating 3 rail tubular track switches, however. 

The restrictions are track rail head, curve radius, quality of track laying/underlayment and turnout configuration. This is based on personal experiences in running scale-wheeled equipment at the club since 2009.

The rail head needs to be prototypically shaped. Atlas, MTH ScaleTrax and RealTrax, and Gargraves/Ross support scale wheels pretty well. The Gargraves track gauge is a bit wider than it should be but works OK.

The curve radius recommendations should be followed -- i.e. if MTH recommends 42" radius don't try running on O-42 (diameter). There are some exceptions, though. The diesels (so far) seem to be able to handle Gargraves O-72 (36" radius) curves OK, but you need to test this on a case-by-case basis with cars coupled. So far I've gotten away with it on the O-72 curve on the club's primary mainline.

Underlayment and the evenness of the track is critical when using the third-rail pickup. The reason for this is that if the track is uneven, the locomotive will ride on the pickup roller and walk out of the track gauge because a flange will be over the top of a running rail. One of the "benefits" of running scale-wheeled locomotives is that the six-axle units will find bad/uneven track. This isn't consistent, though because some locomotives get through while others don't.

Turnouts need to be the numbered variety as the closure rails are straight from the points through the frog. Curve-replacement turnouts can present a problem if taken at speed, but I've been able to creep through O-72 Ross turnouts in the through yard. Quality hi-rail turnouts are critical here.

When running a consist of two or more locomotives, it's important to have the fastest locomotive on point and the slowest bringing up the rear to prevent pushing the lead unit off the rails in a curve. I rarely run more than two locomotives in a consist.

Hope this helps. You can see some of the equipment running on my YouTube channel.

Glad I asked- looks like I'm passing on this. Thanks.

rogerpete posted:

Glad I asked- looks like I'm passing on this. Thanks.

It can be a hassle with steam and I wouldn't recommend it for hi-rail operators. I have two scale-wheeled steam locomotives. I don't run them on the club layout because we have some uneven spots that give them issues. One is an ATSF Blue Goose Hudson, and the other is the 4014 as-restored Big Boy. The Big Boy CAN handle 36" radius on even track, but derailed on a 48" radius uneven curve, so there you go. The H9, having smaller drivers and a short driver wheelbase would probably work, but if you have uneven track or kinks, it will have issues. The other steam I have is hi-rail, but I did buy a 2-rail Sunset ATSF 2-8-0 because I always wanted one and I may set it up to run on 3-rail via a special car in tow so I don't have to put rollers on the locomotive.

I have one 2 rail loco I use on my three rail Gargraves/Ross layout, most reliable locomotive I have. Never stalls on a turnout at slow speed or stopped, doesn't jump the track, pulls a good string of cars, smokes really good and starts only when requested !!

MTH NYC 0-6-0 PS3    Does all my switching.   

clem k posted:

I have one 2 rail loco I use on my three rail Gargraves/Ross layout, most reliable locomotive I have. Never stalls on a turnout at slow speed or stopped, doesn't jump the track, pulls a good string of cars, smokes really good and starts only when requested !!

MTH NYC 0-6-0 PS3    Does all my switching.   

I've seen video of your layout, Clem and your track work is very good.