On March 6th DART Rescue conducted an eight-hour shore construction and testing practice. The practice was conducted at the NASA Ames DART Shore Test Facility. Three double-FEMA Three-Post-Vertical shores were constructed and one was tested. The shore tested had a design load capacity of sixty tons. The test was terminated at approximately 70 tons. The test was terminated prior to shore system failure do to an uneven load being imposed on the shore. Twenty-six members of DART Rescue participated in the exercise. Four other personnel supported the exercise. The team was broken up into three squads.
A new technique was employed to test the shore. A dead load was supported above the shore and a smaller dead load that was supported by the shore. High-pressure airbags were placed between the upper dead load and the lower dead load and shore. The airbags were inflated between the upper load and the lower load that was supported by the shore thus imposing a greater load on the shore system. This was done to provide greater control of the load being imposed on the system than can be done by using just the crane.
For the sake of time, the shore that was tested was partially pre-constructed. The shore did not follow strict FEMA construction standards as stainless steel screws were used in lieu of nails. In addition, two vertical-three-post shores were tied together to form a "Class III" shore. Diagram "A" below shows the setup of the test stand and diagram "B" shows the layout of the shore.
Click on an image to see an enlarged view.