The gravel crawlerway is seen as if from a crawler transporter making a turn to approach Launch Complex 39 pad A at the Kennedy Space Center in Florida. The crawlerways are 130 feet wide, about the size of an 8-lane freeway. The river rock paths have been used since 1966 to move launch vehicles from the Vehicle Assembly Building, or VAB, along the 3.4-mile path to pad A and 6.8 miles to pad B.
The crawlerways were originally built to support transporting Apollo Saturn V rockets to the launch pads. The crawlerways were again used during the Space Shuttle Program moving the 4.5 million-pound shuttles mounted on an 8-million-pound mobile launcher platform atop a six-million-pound crawler transporter -- totaling an 18.5-million-pound vehicle lumbering along to the pad. The paths are specially constructed with four layers. The top is eight inches thick on curves and four inches on straightaway sections. Then there is a four-foot layer of graded, crushed stone. Beneath that is 2.5 feet of fill, followed by one foot of compact fill. Plans call for the crawlerways to be used in the future for transporting launch vehicles from the VAB to pads A and B. For more information, visit http://www.nasa.gov/transition Photo credit: NASA/Kim Shiflett