SC&RA Job of the Year: Go for stack!

In a historic job, Bragg Companies provided engineering, civil improvements, rigging, equipment and labor to relocate the Space Shuttle Endeavour, two solid rocket boosters and External Tank-94 (ET-94) from storage to the new Samuel Oschin Air and Space Center for their “Go for Stack” exhibit.

When moving priceless relics, the pressure is intense. Bragg Companies relocated and installed the Endeavour Space Shuttle, two solid rocket boosters and the external tank (ET-94) from storage to the new Samuel Oschin Air and Space Center.

When moving priceless aerospace relics, the pressure is intense. The Bragg team engineered, 3D printed, fabricated and mounted key components without access to vital NASA data from the Shuttle program, including lifting lugs, tailing lugs and spreader bar bolster frames for the external tanks, as well as jacking frames and slings for the Endeavour.

Spec sheets for components were not necessarily accurate, requiring precise field verification. ET-94 measured 154 feet long, 27 feet 6 inches in diameter and weighed 67,000 pounds. Endeavour stood 59 feet tall, 122 feet long, had a 78-foot wingspan and weighed 176,000 pounds.

Tight clearances

At a crowded jobsite shared with an elementary school, stadiums and museums, vendors operated within a single tree-lined entrance with limited build and breakout areas. Elevation changes and high center-of-gravity moves added complexity. To keep the museum open, much of the work was done at night.

“The upending of these priceless space shuttle articles had never been attempted outside of a NASA-controlled indoor facility,” explained Justin Lambert of Bragg Companies. “Other challenges included wind variations, underground utilities, ground pressures, night-time work and 24/7 media coverage. Over 1,500 engineering hours and five planning methods were submitted to the client.”

Supporting the project were a Liebherr LR1750, Liebherr LTM1400, Enerpac 110-ton Cube Jack System, 20 lines of Goldhofer SPMT and a 200-ton J&R Power Rotator.

Moving and installing ET-94 was a major feat. After it was jacked up, it was transported on a 20-line SPMT fitted with custom jacking frames. Clearances were tight as ET-94 was guided down State Street to the lift area. The LR1750 and LTM1400, along with the Power Rotator, upended and flew ET-94 into the display building, carefully lowering it through a 130-foot scaffold with inches to spare. The main crane had a boom height of 407 feet and a 176-foot radius. ET-94’s delicate foam exterior required extreme caution.

Site alterations

For the Shuttle move, the Pavilion’s back wall was removed and a 109-foot-long, 30-foot-wide ramp was built to bridge a 42-inch elevation change. Geotech surveys, civil work, plating and matting – including 108 road plates and eight crane mats – prepared the surface for operations.

The Endeavour was disconnected from its seismic isolators using the Cube Jack System. It was lifted onto reconfigured jacking frames and moved on the SPMT. The Cube Jack was reintroduced to lift it 12 feet to remove the jacking frames and install bolster towers with custom lashing. It was maneuvered down a slope, around a corner and over a building onto State Street, with as little as 8 inches of clearance.

Late one night, the Endeavour was connected to a vertical sling and upended using the LTM1400 and LR1750. The gross load was 259,600 pounds at a 151-foot radius. Endeavour was slowly lowered into the building and hard mated to the ET-94 for final assembly.

Safety was paramount. Bragg conducted daily Task Hazard Analyses and ensured PPE, equipment inspections, certifications and client-required safety protocols were fully enforced.