Vandenberg AFB Space Launch Complex 6

Executing Tolerances Less than 30 Thousandths of an Inch
Vandenberg AFB, California
Contract Value: 
Year Completed: 

Clark’s retrofit of Space Launch Complex-6 at Vandenberg Air Force Base allowed for the launch of a fleet of Boeing’s new Delta IV rockets. The new complex sits on an abandoned Space Shuttle facility in central California.

The Vandenberg AFB Space Launch Complex 6 (SLC-6) project included a new 650-ton launch table, renovation of, and modifications to, the 325 foot mobile service tower (MST), 270-foot-tall mobile assembly shelter (MAS), and the 200-foot-tall fixed umbilical tower (FUT). The MST features new moveable, multi-level access platforms and a new 50-foot-tall addition on the roof to house a 50-ton overhead crane. FUT doubled in size the 180-foot-tall lightening tower on top of the structure and two 90-foot-long cryogenic fueling swing arms.

Clark also constructed a utilized fixed pad erector. The erector is a bridge deck that is 165 feet in length and weighs 186 tons, a component that elevates the vehicle from its horizontal to vertical position in lieu of stacking the rocket sections in place.

Clark spent ten months building a 77-by-48-by-24-foot, 650-ton, hollow cathedral-shaped structure off-site and outfitted it with a pre-assembled cryogenic utility skid. This structural steel monolith supports the Delta rocket on the launch pad and provides critical blast protection while supplying delicate fuel piping and electrical controls for liftoff. Vacuum jacketed piping and quick disconnect umbilical systems on the launch table supply super-cold liquid hydrogen (-430° F) and liquid oxygen (-360° F) fuel to the rocket.

Several key components of the rocket launch facility were manufactured off-site, and required minute tolerances. For example, the swing arm hinges on the rocket launch table, which were manufactured in Seattle, are 30 feet tall, 30 inches in diameter, and weigh 100,000 pounds each. These hinges fit into hinge actuators, which were manufactured in Milwaukee, with the clearance between hinge pin and hinge actuator equal to less than 1/30,000 of an inch (half the width of a human hair). To ensure these pieces were manufactured to exact specifications, laser measurements were taken of each piece in both Seattle and Milwaukee. Prior to delivery at the jobsite, the hinge actuators were shipped to the hinge pin manufacturing plant in Seattle for a trial run, resulting in a perfect fit.

AGC Build America Award - Federal/Renovation category
AGC of California - Meeting a Difficult Challenge