A drawbridge or draw-bridge is a type of

moveable bridge A moveable bridge, or movable bridge, is a bridge that moves to allow passage for boats or barges. In American English, the term is synonymous with , and the latter is the common term, but drawbridge can be limited to the narrower, historical ...

typically at the entrance to a

castle A castle is a type of fortified structure built during the Middle Ages predominantly by the nobility or royalty and by military orders. Scholars debate the scope of the word ''castle'', but usually consider it to be the private fortified r ...

or tower surrounded by a

moat A moat is a deep, broad ditch, either dry or filled with water, that is dug and surrounds a castle, fortification, building or town, historically to provide it with a preliminary line of defence. In some places moats evolved into more extensive ...

. In some forms of English, including

American English American English, sometimes called United States English or U.S. English, is the set of varieties of the English language native to the United States. English is the most widely spoken language in the United States and in most circumstances ...

, the word ''drawbridge'' commonly refers to all types of moveable bridges, such as

bascule bridge A bascule bridge (also referred to as a drawbridge or a lifting bridge) is a moveable bridge with a counterweight that continuously balances a span, or leaf, throughout its upward swing to provide clearance for boat traffic. It may be single- or ...

vertical-lift bridge A vertical-lift bridge or just lift bridge is a type of movable bridge in which a span rises vertically while remaining parallel with the deck. The vertical lift offers several benefits over other movable bridges such as the bascule and swi ...

s and

swing bridge A swing bridge (or swing span 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 center of gravity, about which the swing span (turning span) can then p ...

s, but this article concerns the narrower historical definition of the term where the bridge is used in a defensive structure. As used in castles or defensive structures, drawbridges provide access across defensive structures when lowered, but can quickly be raised from within to deny entry to an enemy force.

Castle drawbridges

Medieval In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire a ...

s were usually defended by a ditch or

, crossed by a 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 A gatehouse is a type of fortified gateway, an entry control point building, enclosing or accompanying a gateway for a town, religious house, castle, manor house, or other fortification building of importance. Gatehouses are typically the most ...

, consisting of a wooden deck 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 A portcullis (from Old French ''porte coleice'', "sliding gate") is a heavy vertically-closing gate typically found in medieval fortifications, consisting of a latticed Grille (architecture), grille made of wood, metal, or a combination of the tw ...

es and gates. Access to the bridge could be resisted with missiles from machicolations above or arrow slits in flanking

tower A tower is a tall structure, taller than it is wide, often by a significant factor. Towers are distinguished from masts by their lack of guy-wires and are therefore, along with tall buildings, self-supporting structures. Towers are specifi ...

s. The bridge would be raised or lowered using ropes or chains attached to a windlass 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 may refer to: * Bascule bridge, a moveable bridge with a counterweight that continuously balances the span in providing clearance for boat traffic * Bascule (horse), the arc a horse's body takes as it goes over a jump * Bascule light, a sma ...

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 ( ) is a market town in Northumberland, England, of which it is the traditional county town. The population at the 2011 Census was 8,116. The town is on the south bank of the River Aln, south of Berwick-upon-Tweed and the Scottish bo ...

. By the 14th century a bascule arrangement 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 is a brick-built castle, dating from the 15th century, near Herstmonceux, East Sussex, England. It is one of the oldest significant brick buildings still standing in England. The castle was renowned for being one of the ...

. 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 A château (; plural: châteaux) is a manor house or residence of the lord of the manor, or a fine country house of nobility or gentry, with or without fortifications, originally, and still most frequently, in French-speaking regions. No ...

x, including the Château du Plessis-Bourré. In England, two working drawbridges remain in regular use at Helmingham Hall, which dates from the early sixteenth century.

Turning bridge

A bridge pivoted on central

trunnion A trunnion (from Old French "''trognon''", trunk) is a cylindrical protrusion used as a mounting or pivoting point. First associated with cannons, they are an important military development. Alternatively, a trunnion is a shaft that positions ...

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.

Forts

Drawbridges were also used on forts with

Palmerston Forts The Palmerston Forts are a group of forts and associated structures around the coasts of the United Kingdom and Ireland. The forts were built during the Victorian period on the recommendations of the 1860 Royal Commission on the Defence of the ...

using them in the form of Guthrie rolling bridges.

In art

Drawbridges have appeared in films as part of castle sets. When the drawbridge needs to be functional this may present engineering challenges since the set may not be able to support the weight of the bridge in the conventional manner. One solution is to build the drawbridge from steel and concrete before hiding the structural materials behind wood and plaster.

References

{{Authority control Castle architecture Moveable bridges

Castle drawbridges

Turning bridge

Forts

In art

See also

References