I know !! I know !! It's a 2 rail forum.

Look for the center rail pick up rollers. If no rollers it's 2rail or HO

Cross section views, which is usually the case with auction houses. Look at the middle drivers. A two rail engine will have flanges on all drivers, 3 rail engines have blind drivers ( no flange ) and as mentioned above, the big fat middle rail pick up rollers is usually the dead giveaway,…..

Pat

3rd Rail doesn't build HO locomotives.  All 3rd Rail stuff is O-scale, either 3-rail or 2-rail.  The guys above are correct.  Look at the underside of the locomotive, not the tender.

Rollers = O-scale 3-rail

No rollers = O-scale 2-rail

@Bob posted:

3rd Rail doesn't build HO locomotives.

Really?????   I have a friend that models the GN and NP in HO, with an enormous HO layout (takes at least 8 to 10 guys for an operating session), and he has quite a few Sunset/3rd Rail HO NP steam locomotives. I suggest you check the Sunset/3rd Rail website for their HO offerings.

All 3rd Rail stuff is O-scale, either 3-rail or 2-rail.  The guys above are correct.  Look at the underside of the locomotive, not the tender.

Wouldn't the box indicate whether it was O or  HO, and if O, 3-Rail or 2-Rail?

Rollers = O-scale 3-rail

No rollers = O-scale 2-rail

Hi guys.  I appreciate your comments,  thanks.  I wanta be sure.

HO models are marketed under the Sunset Models brand name.  What makes it confusing is that the websites seem to have been consolidated with everything now starting off with 3rdRail.com per this link: http://www.3rdrail.com/ho_scale.htm.

I google search the description. It seems Sunset/3rd Rail has this Road Name and Cab Number on both an O and HO models. I would ask for pictures to share on forum.

I know fully well that Hot Water's friend Jerry Z has a lot of HO brass from Sunset Models.  But, I'll bet that none of those models have a box that reads 3rd Rail.  The 3rd Rail stuff is all O-scale, 2 and 3-rail.  Sunset Models has produced in HO and in O 2-rail.

The original poster's auction house says it has a 3rd Rail locomotive.  That makes it O-scale, period.  The only question is 2-rail or 3-rail.

Hi Southern Fan56,  I went down the same road as you, hence the reason for my confusion.  As soon as I can get my hands on one or the other I'll post.