WHILE WORKING ON STONE BOX ON TOP OF S-3 SECO 8 X 20 DECK SCREEN, EE WAS ATTEMPTING TO PLACE A 18"" X 40"" X 1/2"" PLATE UNDER STONE BOX THAT WOULD CONTROL FLOW OF STONE TO SECO SCREEN. WHILE SLI DING THE PLATE OFF THE MANLIFT ONTO SCREEN, PLATE DROPPED APP 6"" CAUSING HIS FINGER TO BE CAUGHT BETWEEN PLATE AND 2"" SPRAY BAR. THERE WAS ONLY 2' CLEARANCE BETWEEN STONE BOX & SCREEN FRAME,