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LIGO Livingston Observatory NewsArticle 1: CB&I Beam Tube Under Construction
Article 2: Civil Construction At Livingston Nearly Complete!
LIGO's Beam Tube contractor, Chicago Bridge & Iron (CB&I), is well underway in installing the Beam Tube at the Livingston Observatory.
On the X-arm, all tube sections on both Beam Tube modules are welded into place and all girth seams have passed the helium leak test. Crews are now moving equipment over to the Y-arm to continue the installation task. Other CB&I personnel will complete final alignment, using Global Positioning System equipment, and also perform module leak testing on the X-arm.
CB&I fabricates the tube sections at a facility near Denham Springs, about 25 miles from the observatory site. The fabrication equipment was set up and requalified here after being moved last summer from its previous facility in Pasco, Washington. Nearly three-fourths of the 400 tube sections required to finish the observatory have been fabricated. Weld quality continues to be exceptional: Of the nearly 700 tube sections spiral welded for both observatory sites, all have passed the rigorous helium leak test!
The photograph above shows a small portion of the Beam Tube installed on the slab, partially covered by the concrete enclosure. A wrapped pump port valve, a fixed tube support and the tube's vacuum stiffening rings are evident. Although rain is more common at the Livingston site, installation has not been slowed--in fact, it's at an even higher rate than that achieved at the Hanford site.
Civil construction of the Livingston Observatory is winding its way toward completion. LIGO staff has taken joint occupancy of the Operational Support Building (OSB) and has enthusiastically moved into their new quarters.
Despite stubborn non-cooperation from the weather forecasts--28 inches of rain drenched the area in January for example--all the many phases of construction activities are being completed on schedule. Figure 1 shows the corner station with its outdoor carpeting of freshly sprouted rye grass--a valuable part of erosion control that keeps the muddy ground well drained. Joint occupancy has also been declared at both end-stations as well as at the two mid-station buildings.
The completed maintenance building, chiller yard for the corner station, and fire water tank are shown in Figure 2. Stacked on its parking lot and ready for installation are the entry doors that provide emergency and maintenance access to the four-kilometer long Beam Tube enclosure.