| Answer | Crossword Clue |
|---|---|
| NOG | Mine roof support. |
| pillar | solid mass of coal, rock, or ore left standing to support a mine roof |
| SPRAG | Mine roof prop |
| SPRAG | Mine-roof prop |
| SPRAG | Roof prop in a coal mine. |
| SPRAG | Roof prop in a coal mine |
| puncheons | A short post, esp. one used for supporting the roof in a coal mine |
| puncheon | A short post, esp. one used for supporting the roof in a coal mine |
