Can anyone tell me what the maximum track radius is for a heavy weight three axle passenger car, 85 ft long?
Don Grant

roxb@earthlink.net

> Can anyone tell me what the maximum track
> radius is for a heavy weight three axle
> passenger car, 85 ft long?
> Don Grant
Hey Don, I'd say a zero degree curve, IE: a staight line! Now if you want minimum, the truck design does come into some play, and I don't know THAT answer! ;-)
S'
David D.
(up too early this AM, blame it on DaylightSavings time!)


djdewey@cncnet.com

> Hey Don, I'd say a zero degree curve, IE: a
> staight line! Now if you want minimum, the
> truck design does come into some play, and I
> don't know THAT answer! ;-)
> S'
> David D.
> (up too early this AM, blame it on
> DaylightSavings time!)
Hmmmm- Your right regarding daylight savings I should have typed in Minimum degree of curve. Still need a reply

roxb@earthlink.net

One of 3 things generally limits minimum radius curve that a long passenger car can negotiate at very slow (walking) speeds:

Truck swing: on extremely tight curves, the truck frame or (more ususally) the wheels will rub against the car underframe. Gauge widening will help a little with this. Greasing or oiling the contact area will help in marginal situations. Greasing the rails helps too.

Coupler swing: coupler can swing only so far laterally; the shank may be pushed hard over against the carrier iron, which could derail the car or even break the coupler shank. For 1-time moves at dead slow speed, you could chain the cars together to avoid this limitation.

Is it a simple curve (i.e. part of a circle), or an S-curve? S-curves are much worse for two long cars coupled together.

Probably 25 degrees, with kinks to 30 degrees, is possible in many cases. (Anything greater than 22 degrees is a very tight curve, even for industrial spur tracks.)

To find degrees of curvature: get a non-stretchy (dacron is good) string 62.5' long with a knot or ribbon at the center. Hold ends against the inside face of the outside rail. Measure distance in inches between centerpoint of string and inside face of rail. This is the degrees of curvature.

- Doug Debs


doug.w.debs@fcimg.com