Launch pad lift-up

Large-scale renovation projects continue at Kennedy Space Center in Florida where the Space Shuttles are launched. In spring 2005, the National Aeronautics and Space Administration (NASA) contracted Barnhart to lift and secure the launch facility on Launch Pad A so other contractors could work underneath the structure to reinforce it with additional steel and also treat it against corrosion. After the restoration work was completed, Barnhart returned to lower and secure the facility back to its launch pad.

Lifting and securing the maze of pipes, steel and related support structures required detailed and precise planning at every step. Barnhart engineers were challenged with creating a plan for a structure that had never been weighed, and in which engineered lift points had never been identified. Shaun Sipe, regional director at Barnhart, says the major concern was applying the loads to the jacking locations, which were determined by NASA.

“They had chosen six points on the structure that needed to be lifted and we had to figure out how to get underneath those points,” Sipe explains. “For each lift location there was a different challenge to physically getting to the location.”

Once the engineering team devised a way to transfer the load of the structure to the Barnhart jacks, the second challenge was to spread the load to the launch pad foundation. Again, NASA was not sure the amount of load the foundation could withstand.

The third challenge for Barnhart's planning team was to decide how to erect the lifting structure underneath the launch structure, which can rotate around the launch pad. This meant that the lifting towers needed two elevations, one at 124 feet (38 m) and one at 103 feet (31 m) - a 21 foot (6 m) difference between jacking points.

“We asked NASA if we could use the rotational function, the ability to move the structure to its mated position where the Space Shuttle sits for launch, and at that location build the first floor of our tower,” Sipe explains. “Then we swung the structure over that floor and built the second floor, and once again, swinging it back over the second floor and the original tower.”

NASA agreed and Barnhart devised a plan using its Modular Lift Towers and hydraulic jacks to lift and secure the structure. Aside from the challenges of working around the labyrinth of duct work, piping and steel, Barnhart crews would also worry about high winds and lightning. That time of year storms roll through the region almost every afternoon, and if lightning was detected as far as 30 minutes away, the job was shut down. This happened several times.

Plus, there was added scrutiny and pressure in presenting and executing a foolproof plan for lifting such an expensive, highly technical apparatus. “There's the unique value of the structure,” says Sipe. “It's one of a kind, irreplaceable basically and, also, the application of our lift tower and a configuration using a jacking or shoring tower - that was a first for us.”

After the fact, Barnhart and NASA concluded that the weight of the launch structure was about 5 million pounds (2,268 tonnes), although Barnhart only lifted about 2.5 million pounds (1,134 tonnes) of it. The structure is roughly 170 feet (52 m) high and has a radius of more than 80 feet (24 m). •