Precision Scale Niagara

No response, because that is probably a rare model.  Most scale Northerns will have trouble with anything less than 72" radius - Twelve foot diameter.

I have USH, Scale Craft, Max Gray, and scratchbuilt scale Northerns, and they are restricted to my 74" radius test loop.  The problem areas are engine truck/cylinder clearance, and trailing truck/tailbeam clearance.

Have him contact PSC at  psc@ixi.net and ask them about it.

I have a PSC Niagara that I purchased new in 1983 or so. It has been on my former and my present layout continuously since that time but in recent years has been operated only occasionally. So it is not as "tight" or rigid as a new PSC Niagara. My current layout uses Micro-Engineering Code 148 nickel silver track, and I glued the ballast so the track literally cannot move. The engine has had a replacement Pittman motor installed, and I used the Toyota flex tubing for a coupling. The gearbox has had a 12:1 worm installed, and the gearbox drive shaft is pretty "loose" as well. The engine, hauling an eight car heavyweight train, operates around a 69-1/2" radius, but will not operate on a 65-1/4" radius. (The reason for the somewhat odd radii is due to curve easements entering and exiting each curve.) On the sharper radius curves, it is important that the track/rail curvature and also "cross level" be as good as possible. On the 65-1/4" radius, the front wheel set of the front truck derailed. Nothing has been done to increase the range of motion of either the front truck or the trailing truck on my engine. The PT 14 wheel tender is also pretty stiff and a potential source of problems on sharper radii. I also have a USH Niagara that operates well on a radius as low as 60". The PSC Niagara is still the "gold standard" of NYC O Scale Niagaras, and I believe you will have no problem if your minimum radius is 72", although mine operates "OK" on 69-1/2".