tilt bridge
A movable bridge with a curved span that forms an arch when rotated at the ends.
A tilt bridge is a movable bridge with a horizontally curved deck, usually counterbalanced by a vertical arch of a similar curve, which opens by rotating at its two ends. This lifts the curved deck to form an arch, allowing greater clearance below. If the bridge has a counterweighting arch, this must be lowered as the deck rises; therefore the bridge's rotation is limited to 45 degrees so that both the deck and the counterweight provide maximum clearance.
This is a fairly unusual design for a bridge, and is generally used only for footbridges because the curved deck is not optimal for vehicle traffic.
The horizontally curved deck rotates about its two ends and becomes an elevated arch. A counterbalancing arch, when present, moves downward as the deck rises; a single straight leaf lifted at one shoreline is a different opening 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. -
rolling bascule bridge
A movable bridge whose span rises as large gears roll along a shoreline rack, without a fixed hinge. -
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. -
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.