Table bridge

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Table bridge
Open
Ancestor	Plate girder bridge,
Related	Lift bridge, bascule bridge, submersible bridge
Descendant	None
Carries	Automobile, pedestrians
Span range	Short
Material	Steel
Movable	Yes
Design effort	Medium
Falsework required	No

A table bridge is a moveable bridge in which the deck moves along the vertical axis. Hydraulic pillars under the bridge raise the bridge deck to allow barge traffic to pass beneath it. In contrast to a lift bridge, where the deck is pulled upwards along towers, the deck of a table bridge is pushed upwards by otherwise hidden pillars. The name originates from the fact that when open it resembles a table.

The total space required by a table bridge is hardly larger than the bridge deck, which is not the case with a thrust bridge. Unlike a lift bridge this type has only slight visual impact upon its surroundings when closed for use by road traffic. This is very well demonstrated by the Pont levant Notre Dame at Tournai in Belgium.

[edit] A table bridge in operation

Left: Looking across the bridge that crosses the river Scheldt (in front of the first row of buildings); Center: Seen from the same viewpoint, the bridge is up; Right: Overlooking the canalized river, a self-propelled canal boat passes

[edit] See also

• Movable bridge for a list of other movable bridge types
• Submersible bridge for a similar bridge that disappears by moving down