Abstract: Methods and apparatuses negate a measured mechanical twist of an optical fiber by introducing a counteracting twist to bring the net mechanical twist closer to zero, which reduces the fiber's polarization mode dispersion (PMD). A spool of optical fiber having undesirable mechanical twist is mounted and fiber is drawn from the end of the spool to impart a specified counteracting mechanical twist. Additionally, the spool may be controllably rotated by a control system while optical fiber is drawn there from, allowing the system to generate a precise amount of counteracting mechanical twist in the fiber.

Abstract: A rescue ramp (10) for use by a watercraft (11) includes a laterally extending first inflatable tube member (14) attachable to the watercraft (11). Second spaced inflatable tube members (15) are connected at one end to and extend longitudinally from the ends of the first tube member (14). A third inflatable tube member (16) is connected between the second tube members (15) near the other end thereof and is adapted to be positioned in the water. A ramp (17) is connected to the first and second tube members (14, 15) so that when the rescue ramp (10) is inflated and attached to the watercraft (11), a person may traverse from the water to the watercraft (11) or from the watercraft (11) to the water. The first tube member (14) is attached to the watercraft (11) by means of a girt bar (23) releasably mounted on the watercraft (11). The girt bar (23) is connected to a first flap (26) which is detachably connected to a second flap (20) attached to the first tube member (14).