The construction site of the fortified castle of Guédelon had to equip itself with numerous lifting devices. In 2003, the carpenters first made two single-drum squirrel cages (i.e. operated by a single man) to be able to mount the cross vaults of the master tower. Eight years later, in 2011, a double drum squirrel cage, therefore operated by two men and even more efficient, was installed directly on the masonry of the east curtain wall. This new lifting device allows hoisting materials from the bottom of the ditch to the ribbed vault site located on the first floor of the main tower.