The Characteristics of Medieval Bridges
They have projecting piers, triangular in shape, known as cutwaters. These are found on the upper side with the point towards the stream their purpose being to protect the pier from the force of the current and from the impact of trees and other objects borne along by the water.
The spans varied from five feet in the case of small bridges to twenty feet or more in a few cases. The first were semicircular with a barrel vault. In the 13th century pointed arches replaced these arches and groined vaults replaced barrel vaults. Here the main weight was taken on ribs of stone.
Many medieval bridges are humped, especially where the roadway rose over pointed Gothic arches. The gradually flattening of the Gothic arch had the effect of reducing the hump and a somewhat flatter roadway appears in the 15th century.
Often a medieval bridge is extremely long and included a long stone causeway which leads up to it across a flood plain. This is pierced by subsidiary arches which do not regularly have channels of water flowing through them. They are used, however, at times of flood to allow the swollen waters to escape away, instead of ponding up behind the bridge.
Further structures connected with bridges include chapels built for bridge hermits. Gateways and drawbridges were also found.
V. Now you are ready to describe bridges of the Middle Ages and the Renaissance
VI. Continue completing the table:
№ | The period and the country | Type(s) of the bridge | Materials used | Difficulties |
1. | Beam bridge | |||
2. | stones | |||
3. | Ancient Asia | |||
4. | The Middle Ages | |||
5. | The Renaissance |
Дата добавления: 2016-02-20; просмотров: 801;