A cantilever lifting beam system offers an innovative solution to install a drive motor into a small window at a power plant.
At times, a lifting solution requires the use of a highly specialized piece of equipment. Such was the case recently in Amarillo, TX, where the ML Crane Group team of Crane Service and the Alternative Movement Division (AMD) were contracted to remove and replace a 21,700-pound mission critical drive motor in an operating power plant.
After reviewing the site constraints and assessing all the challenges to change out the drive motor, the team determined that the engineered solution was to use their cantilever lifting beam rigged to a 100-ton capacity Link-Belt HTC 86100 truck crane.
The cantilever lifting beam was the safest and most cost-effective way for the crew to pick the motor out of a small access window on the side of one of the power plant buildings.
Short of creating another opening in the building or on the roof, the window provided the only access to the drive motor. Tight clearances of only an inch or two needed to be considered during all aspects of the lifting plan, according to Crane Service’s Amarillo Branch Manager Homer Aikin.
Gear protection
An additional issue was a ceiling-mounted monorail crane track that protruded outside the wall of the building. Multiple pads and softeners would need to be attached to the tracks to protect the slings and rigging that could possibly come
into contact with any sharp edges during the removal and installation of the motor.
“Without the use of the cantilever lifting beam, the customer would have had to design, build and install a new ceiling-mounted monorail crane in order to remove and replace the drive motor as the only access was through the window in the side of the building,” said Aikin. “The tight clearances had to be taken into account at all times.”
The crane was rigged to the beam using two 17-ton shackles and four 8-foot endless slings. The drive motor was rigged to the cantilever lifting beam with four 17-ton shackles and four 8-foot endless slings in a basket. Short slings were used to reduce the height of the rigging as there was minimal overhead clearance.
Ground control
The counterweight on the cantilever lifting beam was adjusted using battery operated, wireless remote control (up to 100 feet), allowing the beam operator on the ground to maintain critical beam balance during the lift. The cantilever lifting beam is perfect for use in refineries, power plants, chemical plants, feed mills, manufacturing and specific jobs that have limited access, Aiken said.
The working cantilever lifting beam weighs 20,000 pounds and has a load limit of 25,000 pounds, although it has been tested at 34,000 pounds with zero deflection. The maximum offset from the crane hook center is 16 feet.
The length of the beam is 28 feet. Counterweights are adjusted using the wireless remote-control system. The ML Crane Group team executed the job flawlessly, and ahead of schedule.
Source: American Cranes & Transport
