Prisoners often refer to certain sounds that occur in the evening as 'the twitching.' A prisoner could hear twitching of metal being smelted in the forge bells, or feel the same thing while lying on a hard surface. A prisoner may also hear a buzzing sound that is not caused by insects or machinery, but rather a prisoner listening to the sounds of their cell
Prisoners have reported hearing the noise of metal being smelted in the bellows of a forge. It is called 'the twitching.' The sound is produced by metal being heated up and being hammered into shape with a hammer or anvil
Prisoners also report feeling vibrations from objects such as chairs and tables when they are sitting on them. This can be felt through their feet as well as up through their legs, hips and spine
Prisoners have also reported feeling vibrations from machinery such as generators and transformers. This can be felt through their feet as well as up through their legs, hips and spine.
slivers of twitching forge metal