A California superior court on Oct. 30 lifted a restraining order, allowing work to resume on a new courthouse in San Diego. Earlier, the San Diego Airport Authority (SDAA) had filed the temporary injunction after it discovered tower-crane boom heights at the nearby construction site were reaching 600 ft. That height exceeds the Federal Aviation Administration’s 512-ft limit for buildings and cranes in the runway approach path of aircraft—in this case, aircraft coming into San Diego International Airport, also known as Lindbergh Field.
The new $555-million Central Courthouse is about 1.25 nautical miles from the airport.
The issue was resolved after the FAA recalculated the maximum height limit for the courthouse’s location and came up with a new limit of 580 ft AMSL, or “above mean sea level,” for temporary structures at the construction site.
The general contractor, Redwood City, Calif.-based Rudolph and Sletten, and its subcontractor, Lakeside, Calif.-based Brewer Crane and Rigging, then agreed to reconfigure their tower cranes so boom lengths do not exceed the new limit.
Howard N. Mills, project executive for Rudolph and Sletten, says all three Liebherr cranes would be recertified and approved by the U.S. Occupational Safety and Health Administration before returning to full operation.
“The reduced boom will restrict our ability to complete construction due to areas of the structure that will now be out of reach of our boom when [the crane is] in its most horizontally extended position,” says Mills.
In the meantime, he says his team will look for an “engineered solution” to all the constraint and configuration challenges the 22-story courthouse faces before completion.
“Once we have completed our study and review of specific activities that will [require] the crane [to be] reconfigured again to reach the longer distance—and most likely break the 580-ft AMSL limit for short periods of time—we will meet with the SDAA and present them a plan for us to agree on before submitting it to the FAA for approval,” says Mills.
The 704,000-sq-ft courthouse is scheduled for completion in late 2016.