Union Mills

[Keith Bingham]

I wonder why it is the bogies on my N-gauge 4-6-2 and 2-6-0 locos quite often jump off the track, anywhere, not  just on pointwork. This applies to all manufacturers, with only Union Mills locos the exception. Perhaps because Union Mills locos are heavier which makes them such good runners. I regret Union Mills are no longer in production.

[Crepello]

I've often found stray ballast to be the culprit, especially with points.  Failing that I suggest you check back-to-backs and baseboard joins. You shouldn't have any problems with decent tracklaying.

[PLD]

I wonder why it is the bogies on my N-gauge 4-6-2 and 2-6-0 locos quite often jump off the track, anywhere, not  just on pointwork. This applies to all manufacturers, with only Union Mills locos the exception. Perhaps because Union Mills locos are heavier which makes them such good runners. I regret Union Mills are no longer in production.

Most likely causes are either track issues - obstructions (such as ballast as suggested) or poor joints; or operational - going too fast around too sharp curves...

The reason for Union Mills being more tolerant of track issues is not the weight as such, but in the way that the front bogies are mounted which is closer to the prototype and means the bogie is carrying some of the weight of the loco rather than just being along for the ride on the end of a loose wavy bar as most models have (a compromise which helps to get around overly tight trainset curves)...