1, Installing technology 
crane rail installing-----crane traveling mechanism and lifting trolley assembly on the ground------bridge frame assembly on the ground-----bridge frame and crane traveling mechanism assembly on the  ground------bridge frame hoisting-----lifting trolley hoisting -----electrical system and other auxiliary facilities hoisting.
2、Main hoisting machine and tools
l    Under the  factory is not capped，according to the structure and  design of 20t overhead crane drawing, adopting a 80t truck crane hoists the crane in order.
l    The calculation of 80t truck crane lifting capacity：
l    In the project, the max. lifting capacity of 20t overhead crane is 23t, choosing a 80t truck crane to hoist, the turning radius of 80t truck crane is 5.5m.the arm length is 24m and the max. lifting capacity is 29.2t.
l    The safety factor of truck crane：0.8
l    The safety lifting capacity of truck crane：29.2×0. 8=23.36t
l    Truck crane safety lifting capacity：23.36t>23t
l    It can meet the safety hoisting need.