Fabric covering for Hangar One?
Process similar to that used to cover Shoreline's tent
If the Navy decides to preserve Hangar One later this year, the historic structure may be covered in a fabric stronger than steel, resulting in an all-white look reminiscent of the hangar when it was first built.
At last week's Moffett Field Restoration Advisory Board meeting, architect Linda Ellis made a presentation on a Teflon-coated Fiberglass fabric that could make preservation of the hangar a more practical option. The fabric is already used on large structures, including the Denver airport, the San Diego convention center and the Georgia Astrodome, which survived Hurricane Katrina. In fact, the oldest example of its use is right here in Mountain View: the 34-year-old Shoreline Amphitheatre.
The Navy is considering the fabric as one of many options in its environmental cleanup of the structure. In 2003, Hangar One was found to have toxic PCBs — short for polychlorinated biphenyls — washing off the coated steel siding and floating in the air inside. The Navy is required to remediate the pollutants, and in the past has stated that dismantling the structure is its best option.
The Navy had initially taken Ellis' presentation off the agenda, which caused an e-mail stir among Hangar One advocates. At the meeting, RAB member Lenny Siegel requested it be put back on the agenda, and Navy environmental coordinator Rick Weissenborn relented on the condition it was brief and general in nature. Weissenborn said, "It would be good to learn about it, it will help me a lot."
Ellis, who was not permitted to go inside the closed hangar, analyzed images of the inside provided by the Moffett Field Historical Society. The barrel vault construction of the hangar suits the fabric well, Ellis said. The frame and foundation are strong enough without the "shear" provided by the current steel siding, which must be removed for toxic cleanup. In the end, the hangar would have fabric stretched over its frame, much like the airship it once housed.
Added benefits would be cost savings on maintenance, since the fabric does not corrode, and it is also translucent enough to allow sunlight through, Ellis said. The fabric can be made with different color patterns, and Ellis proposed the exterior be all white, as it was originally.
The hangar's roof is currently painted black to prevent rain clouds from forming inside the massive structure. Since the fabric is breathable in one direction, it would allow condensation to escape outward, which may negate the need for the black color on the upper section.
The target cost of the fabric covering is $12 million. It is not known exactly how that compares with new steel siding, but Ellis said it would be competitive.
"Thank you, Linda," Weissenborn said after the brief presentation. "That gave me a lot of info I didn't know."
The Navy is preparing a revised Environmental Evaluation and Cost Analysis, which will include the decision for Hangar One and provide a list of alternatives for the its remediation ranging from demolition to restoration. The analysis will be released sometime later this year, and Weissenborn said there will be an effort to reach out to local newspapers so the announcement is not a surprise.
Weissenborn then said that the meeting was his last, and that he would be replaced by another base realignment and closure coordinator, Darren Newton. Siegel moved that the RAB commend Weissenborn for his service and "duress under fire," and jokingly added that his replacement need not wear body armor.
Jill Votaw, the region's public affairs officer, has also been reassigned. Votaw said it was a regular reshuffling of the organization, and mentioned that the new people could provide fresh eyes for the cleanup project.
As part of his handoff to Newton, Weissenborn gave a presentation on Moffett Field cleanup accomplishments, which included a map of 161 pipes and tanks that have leaked petroleum into the ground water. Of the 161, 76 are closed, 51 are being closed and 34 are in operation. Tons of contaminated soil has been removed, he said, and water channels and ponds, and several endangered species, including over 40 turtles, have been saved.
Later that evening the Navy revealed that it has spent $155 million cleaning up Moffett Field over the past 18 years, and estimates it will spend another $78 million before it's done, including the costs of Hangar One cleanup. It could take 200 years to completely remove all groundwater contamination.
E-mail Daniel DeBolt at email@example.com