This piece of timber is driven into the irregular voids between the raw rock face and the structural supports, such as cribbing, steel arches, or tubbing. By tightly packing these gaps, it ensures that ground pressure is transferred evenly onto the support system. Proper installation prevents the rock mass from shifting and gaining momentum before it hits the primary supports.
Heard on the job
Make sure you drive a glut behind every steel set so the arch takes the weight of the roof evenly.
Also heard as
- lagging
- packing