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| {{otheruses4|a type of bridge|the California ghost town|Drawbridge, California}} | |||
| A '''drawbridge''' is a type of ] typically associated with the entrance of a ], but the term is often used to describe all different types of movable bridges, like ]s and ]s. | |||
| Drawbridges may be used to withdraw passage across (rather than allow passage beneath), as is found in military fortifications, and this is the most common use of the term. Simple drawbridges may be found in short canal crossings, where the lifting mechanism is a pair of overhead beams with counterweights that are not a part of the bridge's load bearing structure. | |||
| The most common type of drawbridge consists of a ]en ] with one fixed side (normally with a ]), and the other side attached to the wall from a floor higher than the drawbridge. | |||
| In the Middle Ages, drawbridges were often used to allow or deny access across a ] or ditch. They could be let down to allow people across, or pulled up to deny entry into the castle. | |||
| Now, with cars and trains in need of crossing small waterways without blocking boats from passing, drawbridges have a more peaceful reason for their existence. | |||
| In ], ]s between narrow gauge cane tramways and main lines are being replaced by drawbridges, so that the rails of the main line are completely unbroken by gaps or weak spots. This also allows the main line speeds to be raised. | |||
| Another rail use of drawbridges was on the ] railway in Ireland. This was a sort of monorail, where trains hung on either side of a fence-like track. Road crossings were either a gate-like Stuart section of track or twin drawbridges, that allowed crossing at rail level. | |||
| == See also == | |||
| *] for a list of other movable bridge types | |||
| == Gallery == | |||
| <gallery> | |||
| Image:Fort ticonderoga drawbridge to demilune.jpg|Drawbridge crossing fortification ditches at ] | |||
| Image:Magerebrug.jpg|The famous '']'' (a double drawbridge) in ] | |||
| Image:Drawbridge_amsterdam.jpg|Another drawbridge in ] | |||
| Image:Lake Erie Drawbridge.JPG|], a ] ], passes under the Broadway Bridge on the ] | |||
| Image:Vincent Willem van Gogh 070.jpg|Drawbridge, painted by ] | |||
| Image:Kasteel Doornenburg (100).JPG|Drawbridge at Castle Dornenburg | |||
| Image:Drawbridgeamsterdam333.JPG|Wooden drawbridge in Amsterdam | |||
| </gallery> | |||
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