Twisted bell-tower

The bell-tower of a church is generally composed of a square stone tower on which a capped pyramid of an arrow rests. A twisted bell-tower or bell-tower flame is a Clocher where the arrow is in Spirale, often covered with Ardoise S. There is approximately a hundred bell-towers of this type in Europe

Origins

Two assumptions clash as for the origin of torsion: The ones are the twisted built bell-towers, to carry out an architectural prowess. One can quote in France, that of Mouliherne or Fountain-Guerin, in Anjou, of Treignac in Corrèze or Saint-Outrille in Cher.
One can also quote that of the house of the Compagnons of the Duty to Nantes which is true a work of art . A model explains construction inside the building of it. In Germany, the roof of a door of town of Duderstadt was already twisted at the 15th century, and turns from right to left. Others became it during time, as at the village of Fougeré in Maine-et-Loire, which underwent four recognized tornadoes natural disasters in 40 years.

Certain architects as Purple-the-Duke thinks that they became helicoid following a bad wood seasoning. It is indeed proven that the Charpente of certain bell-towers into growing old moved.

Wood almost always works, its natural direction of rotation being left towards the line. In a bell-tower, it is enough that there is a rotation of one twentieth of degree at the base of the punch, the central and main part of the frame, so that this one reaches a eighth of turn (45°) at the top, involving a torsion of the whole of the frame. Progressively of the years, with the renewal of the roofs, the defect is embellished. The torsion of the bell-tower of the Notre-Dame church to Puiseaux in Loiret is due to a bad wood seasoning.

The weight of the cover, when it is too high, can also possibly make bend the base of the structure, causing a depression of the frame and the gimlet of the bell-tower, it is the case of that of Chesterfield in England, which is covered with lead plate.

Nowadays, it is a test which one makes pass to the apprentices Charpentier S of the companions of the turn of France, to build a model with a bell-tower Hélicoïdal.

Principles of construction of the octagonal bell-towers out of wooden

Octagonal bell-towers

Many twisted bell-towers which became it with time are octagonal, i.e. their arrow comprises eight sides. They are bell-towers of medium-sized cities. Indeed, when a parish of one hundred inhabitants builds his church, its bell-tower will be almost always to two or four slopes. It is a question of cost price. In addition, when the parish exceeds the 10.000 inhabitants, one calls upon craftsmen specialized in this kind of construction.

Constitution

The octagonal bell-towers out of wooden are made up:

of a punch, a vertical beam in the center of the pyramid. It is the showpiece of the building. It is on it which the weight of the frame rests.
of various braces. A brace is a piece of wood which one finds on several levels of the arrow. It is fixed between each face of the roof and the punch, and thus makes it possible to consolidate the whole of the frame.
of pilot wheels, pieces of wood in the shape of cross placed between two wood levels, to prevent those from working, to bore and thus to crumble.

A brace has the maximum of effectiveness when its angle is of 45°. However in the octagonal bell-towers, the pilot wheels of the pyramid have an angle which can be higher than 45°. The octagonal bell-towers are likely thus more to become twisted.

Depression

The bell-tower rests on the punch, all the science of the craftsman being to know to distribute the weight of the cover on masonry or the tower hones some which supports it.

The punch rests him on two beams fixed in cross according to the technique of the Mi-bois. These two beams rest on masonry. This embedding, by removing with each of the two beams part of their thickness, causes a breaking point.

Those can thus bend under the weight, involving the depression of the frame, and bell-tower bores it because, the sides being now too long for the punch, they are bored to compensate.

But this gimlet occurs only when the weight of the cover is too high. That arrives sometimes during a replacement of roof.

Sometimes the roofers use materials different from those envisaged in the beginning. That is probably the case of the bell-tower of Chesterfield, of which the roof in larch, covered with lead sheets, weighs 50 tons, the frame subsided while turning.

Distribution in Europe

There are two concentrations of twisted bell-towers in Europe, France in the Baugeois (in Anjou), and another in Belgium around Herve (in the Province of Liege).

One finds approximately a hundred of it distributed in the following way:

France: more than 65
Germany: 22
Austria: 7
Belgium: 9
Great Britain: 3
Swiss: 4
Denmark: 2
Italy: 1

They all are undoubtedly not indexed, the association of the twisted bell-towers of Europe discovers new each year of it. On the hundred indexed in 2003, one can ensure that thirty-one are voluntary constructions and fifty accidental. The majority are pyramidal except those of Copenhagen and of Rome which is stone constructions, they are distributed in the following way:

octagonal bell-towers (94 out of 101)
hexagonal bell-towers (3: Dinéault, Échirolles and Nogent-on-Vernisson)
pentagonal bell-tower (that of Nantes)
square Pyramid (3: Aubigny-on-Nère, Niedermorschwihr, Orleans)

The breeder materials are generally the slate, but one finds also the tiles, the glazed tiles, the wood shingles, metal (Cuivre, Zinc and Plomb).

The direction of rotation is different from one country to another:

In Germany: 63% turn from right to left
To Austria and Switzerland: 100% turn
To Belgium from right to left: 75% turn
To France from left to right: 78% turn

from left to right

France

Sixty-six bell-towers of this type indexed in France:

Swiss

Four bell-towers of Switzerland

Denmark

Denmark has two twisted constructions which have nothing to do with the twisted bell-towers of the other countries. They are twisted constructions of origin of style baroque.

Italy

As in Denmark this bell-tower has nothing to do with the twisted arrows described above

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