sprag
9.9
A wooden or metal support placed under the roof of a mine to stop it from falling
- noun
- /spræɡ/
- Specialized
:
puntal
- Before beginning work, they checked that every sprag was in place to support the roof of the mine.
Examples
-
Each tunnel in the mine was reinforced with a sprag to ensure the safety of the workers.
-
The miner carefully placed a sprag under the wooden supports to prevent any collapse.
-
According to Van der Graaf project manager Rick Zander, a sprag clutch normally keeps the loaded belt from back-driving the reversible motor.
Academic text (2002)
Synonyms
9.9
A wooden post that holds up the roof of a mine to stop it falling
is made of wood or metal rather than only wood
9.9
A strong post that holds up a roof or wall, for example in a mine
is specific to supporting mine roofs rather than many structural parts
9.9
A long post people drive into the ground to support a building or wall
is placed to prop up a mine roof not to retain soil
Surface Forms
Etymology
The word sprag probably comes from an old word for a small sprig or 'stick' used to prop things up. That's why a sprag in a mine is a simple piece of wood or metal placed under a weak roof to 'support' it.
