NASA Michoud Assembly Facility

Shelter Structures Inc.

The NASA facility in new Orleans installed a large muliti-axis welding machine and needed an environmental containment solution using negative pressure to contain the contaminants generated by the equipment.

The large welding machine extends 25 feet above grade while the height to the bottom of the building trusses is 40 feet and the bottom of the bridge crane serving this area of the building is 33 feet above grade. The challenge was to design, manufacture and install a structure which provided the interior and exterior clearances required while meeting rigid NASA requirements for structural integrity in the form of roof live loads, roof collateral loads, external wind pressure and internal negative pressure. The installation schedule required coordination with other trades and installation on a tight schedule after the gantry crane was installed.

The main section of the shelter is 82.17 feet wide by 102.67 feet long by 31 feet tall. It is connected to an airlock 27 feet wide by 34 feet long with a 24-foot wide by 21-foot high component passage doors and a Vacuum Section 16 feet by 17 feet. A modest slope was added to the roof profile to avoid pounding of water in the event that any of the sprinklers were activated. The tight interior clearances required for the interior gantry crane necessitated crane supports that extended through the fabric membrane. These penetrations had to be securely sealed to maintain the interior negative pressure. One wall of the shelter was located less than two feet from electrical components mounted on the main buildings wall. This required special care in the installation of both the frame and membrane in order to avoid damage to these components.

This flat roofed, negative pressure shelter now allows the MAF Machining Center to be operated without the risk of contamination to the rest of the facility. According to Ross Spiers, site manager for Lou-Con, Inc. and the prime contractor for this project, “Our customer is very pleased with both the design and the on-time completion.”

Project details

Location: New Orleans, La.
Size: 8,500 sq. feet
Fabrics: P.S. Cover (20 oz) by Naizil Coated Fabrics Inc. from Naizil Coated Fabrics Inc.
Engineer: Wayne Rendely, PE
Design: Charly Smail, Shelter Structures, Inc.
Project Manager: Bruce Wallace, Shelter Structures, Inc.
Installation: Kurt Ribelin, KRC Building Solutions, LLC