150 is now described with primary reference to fig5 7 a and 7 b the bin lift and dump mechanism comprises a bin engaging member 151 structured and arranged to grasp a bin b that contains material to be shredded and a powered lift device coupled with the bin engaging member 151 and operable to lift the bin engaging member from a first position e g ground level as shown in solid lines in fig5 and 7 a generally vertically upward to a second position the middle position shown in phantom lines in fig5 that places the bin in a generally upright orientation adjacent the rotary shredder 130 and operable then to move the bin engaging member 151 to a third position the top position in fig5 that tips the bin so as to dump the material to be shredded from the bin into the rotary shredder as best seen in fig6 the powered lift device includes a pair of spaced chains 152 arranged in vertically extending loops about drive sprockets 153 and idler sprockets 154 fig7 a a drive shaft 155 connects the two drive sprockets 153 of the respective chains 152 and the drive shaft is coupled to a hydraulic drive 156 that receives pressurized hydraulic fluid from the hydraulic pump 190 fig1 for driving the shaft and hence the drive sprockets so that the chains rotate a transverse rod 157 is attached at its opposite ends to the chains 152 adjacent.