Deck crane Their specifications are as below: For hydraulic alter breadth crane, there are more than ten types which swl ranging from 0.5t-5.0t, hoisting speed is 20m/min, slewing speed from 1r/min to 2r/min, alter breadth time from 25s to 35m. For electric derrick crane, there are more than six types which swl ranging from 0.5t-5.0t, hoisting speed is 15m/min, slewing speed 0.8r/min, alter breadth time from 40s to 45s. For pneumatic derrick crane, more than five specifications, swl ranging from 05t-2.0t, hoisting speed 20m/min, slewing speed:0.8r/min to 1.5r/min. Wooden packing