With its average thickness of 2.10 m, the eastern curtain wall of the castle was originally capable of resisting ancient artillery composed of trebuchets or other siege engines of the same type, which projected stone balls by a pendulum movement. Such war machines were used during the siege of 1238, which the fortress successfully resisted. Things were completely different from 1324. That year saw the appearance in Europe of gunpowder artillery, which was much more formidable. The old walls no longer provide sufficient protection. It becomes essential to adapt them.
The solution applied at Poilvache consisted of building a new wall in front of the eastern curtain wall of the castle (the most threatened) and filling the intermediate space thus created with earth, up to a certain height. The total thickness thus obtained could approach 6m! It is probably this new masonry which is described as « boloirque » in the texts. Even if it were hit by a ball thrown by a bombard, the mass of earth located at the rear cushioned the shocks and protected the curtain wall.
Access prohibited to the boloirque for security reasons!
Poilvache 