Digest>July 1999

Photo By:

 

Bruce Roberts

Photo Caption:

The unified (or unifying) jack system is groups of jacks working on hydraulic pressure to support, lift, and lower the structure. In moving the lighthouse, the unified jack system consists of sixty jacks that are individually pressurized along with forty "helper" jacks, all working on simple hydraulics (displacement of oil). This red control/monitor panel was specially built for the Hatteras move. The gauges "watch" the pressure of all the jacks. The amount of pressure is measured in pounds per square inch and is read from hoses running from the jacks to this control/monitor panel. When the correct pressure is reached for each jack according to the area it is supporting, and all jacks' shutoff valves are closed, the operator opens the main unifying valve. The lighthouse is lifted at the same time and at the same rate. While the keepers' quarters and the lighthouse are en route to the new site, the jacks are rigged in the three-zone system based on the geometric principle that three points define a plane. An operator can adjust pressure of individual jacks to absorb any stress caused by inconsistencies along the move corridor. In the photo, Pete Friesen, the system's designer, is showing it to the media for the first time.
Back to the edition of: July 1999

Story:

America's tallest lighthouse saved!
Back to the edition of: July 1999

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