Jacking tower

Abstract

A method of self-erecting a jacking tower includes extending a lift assembly, inserting a first module assembly below the extended lift assembly, lowering the lift assembly around the first module assembly, engaging the lift assembly with the first module assembly, extending the lift assembly with the first module assembly engaged, inserting a second module assembly below the extended lift assembly, lowering the lift assembly, and coupling the first and second module assemblies.

What is claimed is: 
     
         1 . A method of self-erecting a jacking tower, the method comprising:
 extending a lift assembly;   inserting a first module assembly below the extended lift assembly;   lowering the lift assembly around the first module assembly;   engaging the lift assembly with the first module assembly;   extending the lift assembly with the first module assembly engaged;   inserting a second module assembly below the extended lift assembly;   lowering the lift assembly; and   coupling the first and second module assemblies.   
     
     
         2 . The method of  claim 1 , further comprising moving the first module assembly along a rail assembly until the first module assembly is located below the lift assembly. 
     
     
         3 . The method of  claim 2 , wherein the step of inserting the second module assembly below the lift assembly includes moving the second module assembly along the rail assembly until the second module assembly is located below the lift assembly. 
     
     
         4 . The method of  claim 1 , further comprising coupling the second module assembly to the rail assembly. 
     
     
         5 . The method of  claim 1 , wherein the step of engaging the lift assembly with the first module assembly includes inserting shear pins on the lift assembly beneath shear structures on the first module assembly and engaging the shear pins with the shear structures. 
     
     
         6 . The method of  claim 1 , further comprising disengaging the lift assembly from the first module assembly. 
     
     
         7 . The method of  claim 1 , wherein the lift assembly includes hydraulic cylinders for lifting and lowering the lift assembly. 
     
     
         8 . The method of  claim 1 , wherein the step of coupling the first and second module assemblies includes inserting a plurality of tapered pins on the second module assembly into a plurality of tapered openings on the first module assembly. 
     
     
         9 . The method of  claim 1 , wherein the second module assembly is a bottom module assembly including an outer frame portion and an inner frame portion, the inner frame portion movable relative to the outer frame portion, the inner frame portion including a plurality of strand jacks connected to cables, the method further comprising raising the inner frame portion of the bottom module assembly relative to the outer frame portion of the bottom module assembly with the strand jacks and cables. 
     
     
         10 . The method of  claim 9 , wherein the first module assembly is a middle module assembly including an outer frame portion and an inner frame portion, the inner frame portion movable relative to the outer frame portion, the method further comprising raising the inner frame portion of the middle module assembly relative to the outer frame portion of the middle module assembly with the strand jacks and cables. 
     
     
         11 . The method of  claim 1 , wherein the first module assembly is a top module assembly including an outer frame portion and an inner frame portion movable relative to the outer frame portion, the method further comprising coupling a head assembly to the inner frame portion of the top module assembly.