Model Railway Forum

hi everyone, hope you can help again. i have a twin track, see pic, and have 2crossovers using peco points. my problem is that i have an american loco, a prrt duplex5548 which is a 4-4-4-4.although this will go over normal turnout points, say to a siding, with no problem it always get stuck and derails over the crossovers. i would like to have this loco run on both tracks but at the moment the only way is to manually transfer the loco which defeats the object somewhat. running with dcc power. any help as always appreciated

I take it you have checked the track is perfectly flat ? , and the loco back to back measurements are all ok. It may be that using two turnouts as your picture is just to much for a 4-4-4-4 . Is it derailing on the front bogie or elsewhere.

Hi, track is flat. Derails when Front bogie reaches 2nd points. Also does it when in reverse and the tender does the same thing

Have you tried turning loco around to see if its the same that way.

Unfortunately yes

do you think replacing turnouts with this would do the trick

I suspect the points have too tight a radius ie Setrack, short or medium. This loco may need a more generous radius.

Have you as suggested by Brian 1951 and checked all wheels Back to Back distance? Special B2B wheel gauges can be purchased to aid this checking which is vital distance.

Not an N guy, but what pops out is the proximity of the two radii, which create a nasty little S curve. This may, or may not be relieved by adding a few centimeters of straight track between the curved sections to reduce the lateral forces.