Moffett Field Hangar, Beam Jacking Procedure, Mountain View, California

A 20-foot-wide, 22-foot-tall, 200-foot-long wooden box beam above the hangar doors had deteriorated and sagged down onto the nested sliding door system.  Liftech designed a jacking procedure and jacking system so Power could raise and repair the box beam.

The jacking system included lifting and holding jacks.  The lifting jacks had low friction bearings to allow the distorted box beam to rotate and shift laterally relative to the jacks as it was raised.  The procedure included vibrating the box steel angle chords to allow the chords and their bolted connections to slip relative to the wood walls and undistort to their original positions. 

Reference:
Power Engineering Construction Company
Alameda, California, USA