Abstract: A crash cushion includes a plurality of resilient, self-restoring tubes each having a center axis and an interior surface. At least some of the tubes are positioned such that respective ones of the center axes are spaced apart in a longitudinal direction. The center axis of at least one tube is substantially perpendicular to a longitudinal axis extending in the longitudinal direction, with the tube defining a diametral plane intersecting and oriented substantially perpendicular to the longitudinal axis. The center axis of the tube lies in the diametral plane. One or more segments are positioned in the tube, with the segments, or portions thereof, disposed on opposite sides of the interior surface of the tube. Each of the segments or portions is symmetrically secured to the tube relative to the diametral plane, with the tube being substantially open between the opposing segments. Various methods of using and assembling the crash cushion are also provided.

Abstract: An energy absorbing vehicle barrier includes a frame defining a compartment. In one embodiment, the frame includes a nose. An energy absorbing cartridge is disposed within the compartment. A retaining device is coupled to the frame, with the retaining device disposed above and extending over at least a portion of an upper surface of the cartridge. The retaining device may contact and engage the upper surface of the cartridge when the barrier is impacted by a vehicle. In this way, the retaining device substantially prevents movement of the cartridge in at least a vertical direction during the impact. Methods of using and assembling the barrier are also provided.

Abstract: A crash cushion includes a plurality of resilient, self-restoring tubes each having a center axis and an interior surface. At least some of the tubes are positioned such that respective ones of the center axes are spaced apart in a longitudinal direction. The center axis of at least one tube is substantially perpendicular to a longitudinal axis extending in the longitudinal direction, with the tube defining a diametral plane intersecting and oriented substantially perpendicular to the longitudinal axis. The center axis of the tube lies in the diametral plane. One or more segments are positioned in the tube, with the segments, or portions thereof, disposed on opposite sides of the interior surface of the tube. Each of the segments or portions is symmetrically secured to the tube relative to the diametral plane, with the tube being substantially open between the opposing segments. Various methods of using and assembling the crash cushion are also provided.

Abstract: A crash cushion includes a plurality of resilient, self-restoring tubes each having a center axis and an interior surface. At least some of the tubes are positioned such that respective ones of the center axes are spaced apart in a longitudinal direction. The center axis of at least one tube is substantially perpendicular to a longitudinal axis extending in the longitudinal direction, with the tube defining a diametral plane intersecting and oriented substantially perpendicular to the longitudinal axis. The center axis of the tube lies in the diametral plane. One or more segments are positioned in the tube, with the segments, or portions thereof, disposed on opposite sides of the interior surface of the tube. Each of the segments or portions is symmetrically secured to the tube relative to the diametral plane, with the tube being substantially open between the opposing segments. Various methods of using and assembling the crash cushion are also provided.

Abstract: An energy absorbing vehicle barrier includes a frame defining a compartment. In one embodiment, the frame includes a nose. An energy absorbing cartridge is disposed within the compartment. A retaining device is coupled to the frame, with the retaining device disposed above and extending over at least a portion of an upper surface of the cartridge. The retaining device may contact and engage the upper surface of the cartridge when the barrier is impacted by a vehicle. In this way, the retaining device substantially prevents movement of the cartridge in at least a vertical direction during the impact. Methods of using and assembling the barrier are also provided.

Abstract: An energy absorbing vehicle barrier includes a frame defining a compartment. In one embodiment, the frame includes a nose. An energy absorbing cartridge is disposed within the compartment. A retaining device is coupled to the frame, with the retaining device disposed above and extending over at least a portion of an upper surface of the cartridge. The retaining device may contact and engage the upper surface of the cartridge when the barrier is impacted by a vehicle. In this way, the retaining device substantially prevents movement of the cartridge in at least a vertical direction during the impact. Methods of using and assembling the barrier are also provided.

Abstract: A crash cushion includes a plurality of resilient, self-restoring tubes each having a center axis and an interior surface. At least some of the tubes are positioned such that respective ones of the center axes are spaced apart in a longitudinal direction. The center axis of at least one tube is substantially perpendicular to a longitudinal axis extending in the longitudinal direction, with the tube defining a diametral plane intersecting and oriented substantially perpendicular to the longitudinal axis. The center axis of the tube lies in the diametral plane. One or more segments are positioned in the tube, with the segments, or portions thereof, disposed on opposite sides of the interior surface of the tube. Each of the segments or portions is symmetrically secured to the tube relative to the diametral plane, with the tube being substantially open between the opposing segments. Various methods of using and assembling the crash cushion are also provided.

Abstract: An energy absorbing vehicle barrier includes a frame defining a compartment. In one embodiment, the frame includes a nose. An energy absorbing cartridge is disposed within the compartment. A retaining device is coupled to the frame, with the retaining device disposed above and extending over at least a portion of an upper surface of the cartridge. The retaining device may contact and engage the upper surface of the cartridge when the barrier is impacted by a vehicle. In this way, the retaining device substantially prevents movement of the cartridge in at least a vertical direction during the impact. Methods of using and assembling the barrier are also provided.

Abstract: A picosecond short cavity dye laser utilizes a piezoelectric translator to vary the length of the optical cavity in the laser to allow continuous tuning of the output wavelength. The laser includes a pair of closely spaced generally flat mirrors forming an optical cavity. A laser dye solution is inserted into the cavity. The short cavity laser is pumped by pulses from another laser to produce picosecond output pulses. The piezoelectric translator, which is attached to one of the mirrors, moves the mirror to tune the laser as an applied DC voltage is varied. The piezoelectric tuning of the dye laser allows the laser to operate in a tunable single axial mode.