A proposal for panel caving a massive ore zone using undercuts 250 ft by 600 ft (76.2 × 183 m) in plan and 14 ft (5.4 m) high is made. If the bulking porosity is 0.075 and caving occurs directly over the undercut, how high above the undercut will the cave zone extend? Draw of ore removes solid material and creates additional void space. If caving extends to the surface, estimate the tons of ore drawn (12 ft3/ton, 0.34m3/ton), if the draw rate is 50,000 tpd, what is the elapsed time from undercut completion until the draw appears at the surface?