Short holes are often identified when measuring a pattern of drill holes for depth (dipping).

Where the number of short holes is excessive it may be necessary to drill new holes close to the original short hole.

(The alternative is to run the drill back down the original hole but this us not common practice owing to misalignment issues)

The new holes are called 'redrills' and the original short holes are abandoned.

Redrills are often identified with a specific naming convention. Here is it _RD.

Redrills and abandoned holes should be shown on the charge plans to ensure

• redrilled holes for loading are properly identified
• short holes that are redrilled are not loaded
• abandoned holes are properly identified for backfilling
• abandoned holes out of position are not loaded.

Drill pattern showing abandoned holes (K243, K202) and redrill holes (K243_RD, K202_RD)