Why Offset Bolsters in Many MT Trucks?

[tehachapifan]

This is one of those things where I may have known the answer at one time but forgot. That said, at the moment I can't come up with a reason for the bolster holes not being centered.

[ednadolski]

I had always assumed it was to make room for the truck-mount coupler box.

Ed

[nkalanaga]

Ed:  That's the only reason I've heard.  Since other manufacturers were already using centered bolster holes, there wasn't any truck-related operational reason.

My guess is that Kadee wanted to use their existing 1025 (MT-5) couplers for truck mounting, and had to decide whether to extend the coupling distance, or offset the trucks.  In the early 1970s, they probably felt that more people would like the closer coupling than properly aligned bolsters, especially since the body-mounted couplers coupled a lot closer than Rapidos.

They wouldn't have had to make the choice if they'd used 1015 couplers on the trucks, but those hadn't been introduced yet...

[Gozer the Gozerian]

The offset is to give the couplers a bit more swing, much the same way we do it in a more extreme manner with the Heavyweights.  It helps keep the ends of the cars as close to the center of an arc during transitioning trough a curve.  For body mount applications, say the car you are converting has the bolster that might be too far forward, you can turn the truck around and have the visual center of the truck further back...minor application I know but it was in some of the notes I saw in the archives many years ago.

Joe

[tehachapifan]

Good info! Makes sense. Thanks!