definition
strict definition
rolling bascule bridge
A movable bridge whose span rises as large gears roll along a shoreline rack, without a fixed hinge.
A rolling bascule bridge is an openable bridge whose span rises when large gears at the shoreline roll on a rack. Although the opening motion of this type is similar to a drawbridge or a bascule bridge, it operates without a hinge.
The support rolls along the rack while the span rises. The combined rolling and lifting motion differs from turning around a stationary hinge.
Its raised appearance can resemble a drawbridge or a hinged bascule bridge. The rack-guided rolling mechanism, rather than the open silhouette alone, establishes this form.
Related definitions
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bascule bridge
A movable bridge with one or two leaves that rise on hinges with assistance from counterweights. -
curling bridge
A movable bridge with a flexible or segmented span which opens by curling vertically. -
drawbridge
A hinged bridge lifted at its free end by chains, cables, or ropes, without a counterweight at the hinge. -
folding bridge
A movable bridge with a segmented span that folds horizontally like an accordion to open the crossing. -
retractable bridge
A movable bridge whose deck opens by sliding back from the channel over or under its approach. -
submersible bridge
A movable bridge whose span sinks below water to allow boat traffic to move over it. -
swing bridge
A movable bridge with a span that turns horizontally about a fixed pivot at its center or one end. -
table bridge
A movable bridge whose span is pushed upward from below at both ends, usually by hydraulic pillars. -
tilt bridge
A movable bridge with a curved span that forms an arch when rotated at the ends. -
transporter bridge
A bridge which conveys traffic across its span via gondolas suspended from a high track or cables. -
vertical-lift bridge
A movable bridge whose level span is raised along towers at its ends, usually by counterweighted cables.