Stull stoping

Stull stoping is an underground hardrock mining method that uses systematic or random timbering ("stulls") placed between the foot and hanging wall of the vein. This method require that the hanging wall and often the footwall be of competent rock as the stulls provide the only artificial support. This type of stope has been used up to a depth of 3,500 feet (1,077 m) and at intervals up to 12 feet (3.7 m) wide.

ource

"SME Mining Engineering Handbook", Volume 1