In this project, we further developed and tested a "ZipperMast" for small robots and legacy manned vehicles. The ZipperMast knits three coiled bands of spring steel together to form a rigid mast. As the mast is extended, it draws up a cable connecting the host platform to the payload, typically antennas and sensors. Elevating the payload improves line of sight, and thus improves radio communication and surveillance situation awareness. When the mast is retracted, the interior cable slides into a horizontal tray. The ZipperMast is a scaleable design. We have made systems that elevate to 8 and 20 feet. The 8 foot ZipperMast collapses to less that 8 inches high and 8 inches wide. The 20 foot ZipperMast collapses to less that 12 inches high and 18 inches wide. In this paper we report on tests of the mechanical properties of the mast, specifically the strength and stiffness under quasi-static and impulsive loading. These properties are important for specifying constraints on height as a function of speed and payload and on speed as a function of height and payload in order to ensure that the mast will not fail in the event of sudden stop, as in the event of a collision.