Patent attributes
A cant indication apparatus includes a spirit level, at least one light receiving optical fiber, and at least one light transmitting and cant indicating optical fiber. The spirit level includes a first fluid with at least one of a first light transmittance or absorbance, and a second fluid with at least one of a second light transmittance or absorbance. A position of a bubble formed by the second fluid in the first fluid indicates at least an uncanted orientation and a canted orientation. The at least one light receiving optical fiber includes a light receiving end, and a spirit level connection end proximate to the spirit level. The at least one light transmitting and cant indicating optical fiber includes a spirit level connection end proximate to the spirit level, and an orientation indication end. Illumination through the orientation indication end indicates the bubble is in the uncanted orientation.
