Drawbridge
Overview
 
A drawbridge is a type of movable bridge typically associated with the entrance of a castle
Castle
A castle is a type of fortified structure built in Europe and the Middle East during the Middle Ages by European nobility. Scholars debate the scope of the word castle, but usually consider it to be the private fortified residence of a lord or noble...

 surrounded by a moat
Moat
A moat is a deep, broad ditch, either dry or filled with water, that surrounds a castle, other building or town, historically to provide it with a preliminary line of defence. In some places moats evolved into more extensive water defences, including natural or artificial lakes, dams and sluices...

. The term is often used to describe all different types of movable bridges, like bascule bridge
Bascule bridge
A bascule bridge is a moveable bridge with a counterweight that continuously balances the span, or "leaf," throughout the entire upward swing in providing clearance for boat traffic....

s and lift bridge
Lift bridge
A vertical-lift bridge or lift bridge is a type of movable bridge in which a span rises vertically while remaining parallel with the deck....

s.
Medieval
Middle Ages
The Middle Ages is a periodization of European history from the 5th century to the 15th century. The Middle Ages follows the fall of the Western Roman Empire in 476 and precedes the Early Modern Era. It is the middle period of a three-period division of Western history: Classic, Medieval and Modern...

 castle
Castle
A castle is a type of fortified structure built in Europe and the Middle East during the Middle Ages by European nobility. Scholars debate the scope of the word castle, but usually consider it to be the private fortified residence of a lord or noble...

s were usually defended by a ditch or moat
Moat
A moat is a deep, broad ditch, either dry or filled with water, that surrounds a castle, other building or town, historically to provide it with a preliminary line of defence. In some places moats evolved into more extensive water defences, including natural or artificial lakes, dams and sluices...

, crossed by wooden bridge. In early castles the bridge might be designed to be destroyed or removed in the event of an attack, but drawbridges became very common.
Unanswered Questions
Encyclopedia
A drawbridge is a type of movable bridge typically associated with the entrance of a castle
Castle
A castle is a type of fortified structure built in Europe and the Middle East during the Middle Ages by European nobility. Scholars debate the scope of the word castle, but usually consider it to be the private fortified residence of a lord or noble...

 surrounded by a moat
Moat
A moat is a deep, broad ditch, either dry or filled with water, that surrounds a castle, other building or town, historically to provide it with a preliminary line of defence. In some places moats evolved into more extensive water defences, including natural or artificial lakes, dams and sluices...

. The term is often used to describe all different types of movable bridges, like bascule bridge
Bascule bridge
A bascule bridge is a moveable bridge with a counterweight that continuously balances the span, or "leaf," throughout the entire upward swing in providing clearance for boat traffic....

s and lift bridge
Lift bridge
A vertical-lift bridge or lift bridge is a type of movable bridge in which a span rises vertically while remaining parallel with the deck....

s.

Castle drawbridges

Medieval
Middle Ages
The Middle Ages is a periodization of European history from the 5th century to the 15th century. The Middle Ages follows the fall of the Western Roman Empire in 476 and precedes the Early Modern Era. It is the middle period of a three-period division of Western history: Classic, Medieval and Modern...

 castle
Castle
A castle is a type of fortified structure built in Europe and the Middle East during the Middle Ages by European nobility. Scholars debate the scope of the word castle, but usually consider it to be the private fortified residence of a lord or noble...

s were usually defended by a ditch or moat
Moat
A moat is a deep, broad ditch, either dry or filled with water, that surrounds a castle, other building or town, historically to provide it with a preliminary line of defence. In some places moats evolved into more extensive water defences, including natural or artificial lakes, dams and sluices...

, crossed by wooden bridge. In early castles the bridge might be designed to be destroyed or removed in the event of an attack, but drawbridges became very common. A typical arrangement would have the drawbridge immediately outside a gatehouse
Gatehouse
A gatehouse, in architectural terminology, is a building enclosing or accompanying a gateway for a castle, manor house, fort, town or similar buildings of importance.-History:...

, consisting of a wooden deck
Deck (bridge)
A bridge deck or road bed is the roadway, or the pedestrian walkway, surface of a bridge. It is not to be confused with any deck of a ship.The deck may be of concrete,wood which in turn may be covered with asphalt concrete or other pavement...

 with one edge hinged or pivoting at the gatehouse threshold, so that in the raised position the bridge would be flush against the gate, forming an additional barrier to entry. It would be backed by one or more portcullis
Portcullis
A portcullis is a latticed grille made of wood, metal, fibreglass or a combination of the three. Portcullises fortified the entrances to many medieval castles, acting as a last line of defence during time of attack or siege...

es and gates. Access to the bridge could be resisted with missiles from machicolations above or arrow slits in flanking tower
Tower
A tower is a tall structure, usually taller than it is wide, often by a significant margin. Towers are distinguished from masts by their lack of guy-wires....

s.

The bridge would be raised or lowered using ropes or chains attached to a windlass
Windlass
The windlass is an apparatus for moving heavy weights. Typically, a windlass consists of a horizontal cylinder , which is rotated by the turn of a crank or belt...

 in a chamber in the gatehouse above the gate-passage. Only a very light bridge could be raised in this way without any form of counterweight, so some form of bascule
Bascule bridge
A bascule bridge is a moveable bridge with a counterweight that continuously balances the span, or "leaf," throughout the entire upward swing in providing clearance for boat traffic....

 arrangement is normally found. The bridge may extend into the gate-passage beyond the pivot point, either over a pit into which the internal portion can swing (providing a further obstacle to attack), or in the form of counterweighted beams that drop into slots in the floor.

The raising chains could themselves be attached to counterweights; in some cases a portcullis provides the weight, as at Alnwick
Alnwick Castle
Alnwick Castle is a castle and stately home in the town of the same name in the English county of Northumberland. It is the residence of the Duke of Northumberland, built following the Norman conquest, and renovated and remodelled a number of times. It is a Grade I listed building.-History:Alnwick...

. By the 14th century a bascule arrangement
Bascule bridge
A bascule bridge is a moveable bridge with a counterweight that continuously balances the span, or "leaf," throughout the entire upward swing in providing clearance for boat traffic....

 was provided by lifting arms (called "gaffs") above and parallel to the bridge deck whose ends were linked by chains to the lifting end of the bridge; in the raised position the gaffs would fit into slots in the gatehouse wall ("rainures") which can often still be seen, as at Herstmonceux Castle
Herstmonceux Castle
Herstmonceux Castle is a brick-built Tudor castle near Herstmonceux, East Sussex, United Kingdom. From 1957 to 1988 its grounds were the home of the Royal Greenwich Observatory...

. Inside the castle the gaffs were extended to bear counterweights, or might form the side-timbers of a stout gate which would be against the roof of the gate-passage when the drawbridge was down, but would close against the gate-arch as the bridge was raised.

In France, working drawbridges survive at a number of château
Château
A château is a manor house or residence of the lord of the manor or a country house of nobility or gentry, with or without fortifications, originally—and still most frequently—in French-speaking regions...

x, including the Château du Plessis-Bourré
Château du Plessis-Bourré
Château du Plessis-Bourré is a château in the Loire Valley in France, situated in the commune of Écuillé in the Maine-et-Loire department.Built in less than 5 years from 1468 to 1472 by Finance Minister Jean Bourré, the principal advisor to King Louis XI, the château has not been modified...

. In England, two working drawbridges remain in regular use at Helmingham Hall
Helmingham Hall
Helmingham Hall is a moated manor house in Helmingham, Suffolk, England. It was begun by John Tollemache in 1480 and has been owned by the Tollemache family ever since. The house is built around a courtyard in typical late medieval/Tudor style....

, which dates from the early sixteenth century.

Turning bridge

A bridge pivoted on central trunnion
Trunnion
A trunnion is a cylindrical protrusion used as a mounting and/or pivoting point. In a cannon, the trunnions are two projections cast just forward of the centre of mass of the cannon and fixed to a two-wheeled movable gun carriage...

s is called a turning bridge, and may or may not have the raising chains characteristic of a drawbridge. The inner end carried counterweights enabling it to sink into a pit in the gate-passage, and when horizontal the bridge would often be supported by stout pegs inserted through the side walls. This was a clumsy arrangement, and many turning bridges were replaced with more advanced drawbridges.

See also

  • Bascule bridge
    Bascule bridge
    A bascule bridge is a moveable bridge with a counterweight that continuously balances the span, or "leaf," throughout the entire upward swing in providing clearance for boat traffic....

  • Drawbridge mentality
    Drawbridge mentality
    Drawbridge mentality describes the attitude of those people who migrate to more exclusive or more "unspoiled" communities and thereafter campaign to preserve the tranquility of that community by opposing further inward migration by people or businesses and, possibly, any development or...

  • Hinge
    Hinge
    A hinge is a type of bearing that connects two solid objects, typically allowing only a limited angle of rotation between them. Two objects connected by an ideal hinge rotate relative to each other about a fixed axis of rotation. Hinges may be made of flexible material or of moving components...


  • Linkspan
    Linkspan
    A linkspan or link-span is a type of drawbridge used mainly in the operation of moving vehicles on and off a RO-RO vessel or ferry.Linkspans are usually found at ferry terminals where a vessel uses a combination of ramps either at the stern, bow or side to load or unload cars, vans, trucks and...

  • Lists of rail accidents
  • Swing bridge
    Swing bridge
    A swing bridge is a movable bridge that has as its primary structural support a vertical locating pin and support ring, usually at or near to its centre of gravity, about which the turning span can then pivot horizontally as shown in the animated illustration to the right...



Gallery

Some of the bridges shown are really bascule bridge
Bascule bridge
A bascule bridge is a moveable bridge with a counterweight that continuously balances the span, or "leaf," throughout the entire upward swing in providing clearance for boat traffic....

s.
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