How many yards will a tri-axle dump truck hold?

i believe a tri axlw will hold about 14 yards of top soil A Tri-Axle will hold up to20 - 25 yards of soil depending on weight. A Tandem will hold about 14 - 17 yards of soil. Tri-axle can hold about 30 yards of mulch.

How much it will hold, depends on the size of the box. I can 'legally' load 20 yds of

'pit-run' (gravel) in a 24 foot tandem trailer (in my province).