Tubular bridge

From Wikipedia, the free encyclopedia

Tubular bridge
Conwy Railway Bridge
Conwy Railway Bridge
Ancestor: Plate girder bridge
Related: Box girder bridge, Skyway, Jetway
Descendant: None
Carries: heavy rail
Span range: Medium
Material: Wrought iron, steel
Movable: No
Design effort: Low
Falsework required: Depends upon length and degree of prefabrication

A tubular bridge is a bridge built as a rigid box girder section within which the traffic is carried. Famous examples include the original Britannia Bridge over the Menai Strait and the Conwy railway bridge over the River Conwy, both designed and built by Robert Stephenson between 1846 and 1850. In the case of the Britannia Bridge this technology allowed a bridge 1511-ft long to be constructed, when until then the longest wrought iron span had been 31 ft 6 inches.

Section of the original wrought-iron tubular Britannia Bridge standing in front of the modern bridge
Section of the original wrought-iron tubular Britannia Bridge standing in front of the modern bridge


[edit] See also

  • Box girder bridge - a similar bridge that carries the traffic atop the box.
  • Covered bridge - a type which may employ a variety of structures but which also encloses the traffic (for the protection of the bridge)
  • Jetway - a movable bridge that carries pedestrians from a terminal to an aircraft.
  • Skyway - a bridge connecting buildings at an elevation above the ground