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Visiting the castle Events ;

• Visiting the castle ;

• Landscape environment  ;

• Annabel ROMERO 2006 ;

• Costa-Rica's family visit ;

• Casta Diva, Vox Populi, 2007 ;

• The Salt Strawberries, 2008 ;

• Show de Divas, 2009 ;

Historical background ;

• Saving the ruins ;

Supplements ;

• The Mézerville Cultural Association ;

• Catharism ;

• Woad ;

• J D’A deposition ;

• I J deportation ;

• The Mézerville in Costa Rica ;

• Gaston Phébus ;

• Mézerville a gastronomique land ;

• Bibliography ;

Medieval machines ;

• Introduction ;

• Revolving crane ;

• Pile-driver  ;

Historical geometrical curiosities ;

• General presentation ;

• Heptagon sketch ;

• Angle trisection ;

• Nonagon sketch ;

• The golden number ;

• The golden number geometry ;

• Squaring the circle ;

Contact ;

• Jacques Demichelis : Goodbye ;

• Form ;

• Castle’s owners ;

• Castle’s location ;

• Public opening time ;

• Links ;

A revolving crane

There are two big wheels, with integral manual levers operated by 1 to 4 people, and an axle on which the lifting rope is wound. The tread diameter is 20 cm, the big wheels diameter is 2.4 m. – which gives a multiplier strain of 12 on fixed span rope.

An “arrow” or “arm” 6.5m long, with a pulley on top, is made of two integral beams with an axle that swivels in a fork, which is supported by four horizontal stringers making the engine’s pedestal.
The whole structure allows a charge lift of 5 m. and a 360° swivel. The centre of gravity is very near the stringers so a 400 kg charge on a single end can be lifted without counterweight. If four men exert a 25 kg strain on the big wheels, 1200 kg can be lifted with a counterweight! A pulley block would double these charges.

Let’s not forget that this wooden apparatus was built according to traditional carpentry techniques which means easily taken apart, transportable and put together again at each elevation level of the building, the heaviest pieces weighing under 120 kg.

We also devised a “grappler arm”, and were pleased to see how easily it could be used for the accurate setting out of heavy stones on a wall, for instance (of 200 or 300 kg).