Drawbridge
A defensive bridge raised to deny entry to attackers.
A drawbridge is a movable bridge, most often found at the entrance to a castle or tower that is surrounded by a moat. In its original defensive role, it allowed people to cross a ditch or moat when lowered, but could be pulled up quickly from inside to block an enemy attack.
In medieval castles, the usual defense was a ditch or moat crossed by a wooden bridge. Early castles sometimes had bridges designed to be destroyed or removed during an attack, but drawbridges became very common. Typically, the drawbridge was placed just outside a gatehouse. It consisted of a wooden deck with one edge hinged at the gatehouse threshold, so that when raised it stood flush against the gate, forming an extra barrier. Behind it were one or more portcullises and gates. Defenders could attack anyone on the bridge with missiles from machicolations above or arrow slits in flanking towers.
The bridge was raised or lowered using ropes or chains attached to a windlass in a chamber above the gate passage. Only a very light bridge could be raised this way without a counterweight, so some form of bascule arrangement was usually used. The bridge might extend past the pivot point into the gate passage, either over a pit where the inner part could swing down (creating another obstacle) or as counterweighted beams that dropped into floor slots. The raising chains could themselves be attached to counterweights; in some cases, a portcullis provided the weight, as at Alnwick. By the 14th century, a bascule arrangement used lifting arms called "gaffs" above and parallel to the bridge deck, with their ends linked by chains to the lifting section. When raised, the gaffs fit into slots in the gatehouse wall, which can still be seen at places like Herstmonceux Castle. Inside the castle, the gaffs were extended to carry counterweights, or they formed the side timbers of a stout gate that rested against the roof of the gate passage when the bridge was down, but closed against the gate arch as the bridge rose.
In France, working drawbridges survive at several châteaux, including the Château du Plessis-Bourré. In England, two working drawbridges are still in regular use at Helmingham Hall, which dates from the early sixteenth century.
A bridge pivoted on central trunnions is called a turning bridge, which may or may not have the raising chains typical of a drawbridge.
- Type
- Defensive structure
- Period
- Medieval and later
- Common location
- Castle or tower entrance
- Primary function
- Access control and defense
- Typical material
- Wooden deck
- Mechanism
- Ropes or chains attached to a windlass
Lore & Background
Medieval castles were usually defended by a ditch or moat, 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, 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 portcullises and gates. Access to the bridge could be resisted with missiles from machicolations above or arrow slits in flanking towers.
Reader's Guide
The drawbridge was a key element of medieval defensive architecture, allowing a castle's inhabitants to control access across a moat or ditch. Its design evolved to include counterweights and bascule arrangements to make raising easier. In some cases, the bridge extended into the gate-passage beyond the pivot point, either over a pit or with counterweighted beams. By the 14th century, lifting arms called gaffs were used, linked by chains to the bridge. Working drawbridges survive at a number of châteaux in France, including the Château du Plessis-Bourré, and in England at Helmingham Hall. Drawbridges were also used on Palmerston Forts in the form of Guthrie rolling bridges. In modern film sets, functional drawbridges may be built from steel and concrete hidden behind wood and plaster.
Did You Know?
- In some forms of English, including American English, the word drawbridge commonly refers to all types of moveable bridges, such as bascule bridges, vertical-lift bridges and swing bridges.
- A bridge pivoted on central trunnions is called a turning bridge, and may or may not have the raising chains characteristic of a drawbridge.
- Working drawbridges survive at the Château du Plessis-Bourré in France and at Helmingham Hall in England.
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