An aluminum mill in Alabama approached Barnhart seeking an alternative method to roof removal to remove and replace a 150,000-pound motor that was in a very congested area surrounded by equipment. Barnhart’s engineering team laser scanned the area and began developing a concept.
The concept Barnhart developed involved a gantry supported cantilever beam with moving counterweight mounted to a hydraulic platform trailer. Due to the motor being installed off center of the door opening, the system was also mounted to a hydraulic rotation table that would provide the slight rotation required to get the hook positioned directly over the motor’s center of gravity.
While removing the existing motor, the rigging method forced the motor to come into extremely tight clearance with the motor mount. The method was adjusted when bringing the new motor in to ensure adequate clearance.
The team rigged the motor tightly to allow it to go over the alignment block positioned in front of the motor. Then the motor was set to blocking, the chains were lengthened and the motor set down into the final position. Barnhart’s method saved the customer time and nearly $1 million due to not having to remove the roof and mobilize a large crane to perform the motor lifts from above.