Pullman car weights, turn radii of 3-axle trucks Options

[The Dutchman]

The old Pullman cars came in a plurality of designs but typically had a massive center beam underneath the platform level, onto which the flooring was built, onto which the sides and roof were riveted. The 3-axle trucks apparently weighed in at 42,000 lbs (presumably the pair). Does anyone know the typical design weight of such a car? the question arises as the cars upgraded at some historical point (presumably in the change-over from wood to metal cars) from two-axle to three-axle, presumably for weight reasons. The Colorado Railcar DMU units came in at 175,000 lbs and used 2-axle trucks. Would anyone know the minimum turning radii of the 2-axle vs. 3-axle trucks? At what weight point is it necessary to go to a 3-axle truck to distribute the weight properly? And is this point a function of the rail weight?