Bald Arch
Encyclopedia
Bald arch is a technical term used by engineers to describe the decay of the crucial keystone
s in medieval buildings, particularly churches and cathedral
s.
s produced by late 19th Century pipe organs
, the proliferation of the 32 feet pipe particularly responsible, although some blame the vibrations from inner city
traffic
. The stone
becomes crumbly, producing a fine powdered stone. Also, large sections loosen and often fall off, creating another hazard
.
s, although were it not for this support the buildings would be detrimentally undermined.
in the village of Ramsbury
in England was closed temporarily while the masonry was reinforced with steel braces. An example of the damaged stonework is on display in the shop and has been made into a box
for donations.
Keystone (architecture)
A keystone is the wedge-shaped stone piece at the apex of a masonry vault or arch, which is the final piece placed during construction and locks all the stones into position, allowing the arch to bear weight. This makes a keystone very important structurally...
s in medieval buildings, particularly churches and cathedral
Cathedral
A cathedral is a Christian church that contains the seat of a bishop...
s.
Causes and symptoms
Many attribute the decay to low pitch vibrationOscillation
Oscillation is the repetitive variation, typically in time, of some measure about a central value or between two or more different states. Familiar examples include a swinging pendulum and AC power. The term vibration is sometimes used more narrowly to mean a mechanical oscillation but sometimes...
s produced by late 19th Century pipe organs
Organ (music)
The organ , is a keyboard instrument of one or more divisions, each played with its own keyboard operated either with the hands or with the feet. The organ is a relatively old musical instrument in the Western musical tradition, dating from the time of Ctesibius of Alexandria who is credited with...
, the proliferation of the 32 feet pipe particularly responsible, although some blame the vibrations from inner city
City
A city is a relatively large and permanent settlement. Although there is no agreement on how a city is distinguished from a town within general English language meanings, many cities have a particular administrative, legal, or historical status based on local law.For example, in the U.S...
traffic
Traffic
Traffic on roads may consist of pedestrians, ridden or herded animals, vehicles, streetcars and other conveyances, either singly or together, while using the public way for purposes of travel...
. The stone
Rock (geology)
In geology, rock or stone is a naturally occurring solid aggregate of minerals and/or mineraloids.The Earth's outer solid layer, the lithosphere, is made of rock. In general rocks are of three types, namely, igneous, sedimentary, and metamorphic...
becomes crumbly, producing a fine powdered stone. Also, large sections loosen and often fall off, creating another hazard
Hazard
A hazard is a situation that poses a level of threat to life, health, property, or environment. Most hazards are dormant or potential, with only a theoretical risk of harm; however, once a hazard becomes "active", it can create an emergency situation. A hazard does not exist when it is not...
.
Remedies
The arches are reinforced using steel trusses. Some opponents believe that this spoils the look of the arches, believing it makes them look like dental braceDental brace
Dental braces are devices used in the orthodontic industry that help align and straighten teeth and help to position them with regard to a person’s bite, while also working to improve dental health...
s, although were it not for this support the buildings would be detrimentally undermined.
Recent examples of bald arch
On Wednesday, 14 March 2003, the church of St AlfwoldAlfwold
Alfwold was a saint and Bishop of Sherborne in Dorset.-Life:Little is known of him apart from the information given by William of Malmesbury. He was at first a monk of Winchester, then was consecrated Bishop of Sherborne in 1045, succeeding his own brother Brithwyn...
in the village of Ramsbury
Ramsbury
Ramsbury is a village in Ramsbury and Axford civil parish in the English county of Wiltshire. The village is in the Kennet Valley near the Berkshire boundary. The nearest towns are Hungerford about east and Marlborough about west. The much larger town of Swindon is about to the north.The civil...
in England was closed temporarily while the masonry was reinforced with steel braces. An example of the damaged stonework is on display in the shop and has been made into a box
Box
Box describes a variety of containers and receptacles for permanent use as storage, or for temporary use often for transporting contents. The word derives from the Greek πύξος , "box, boxwood"....
for donations.
Further reading
- The Observer’s Book of Architecture – John Penoyre and Michael Ryan
- The Churchwarden’s Guide to Church Maintenance – James Redcock