Example use airleg drill / jackleg drill

[airleg drill (UK) == jackleg drill (USA)]

Trying to give some idea what using an airleg drill looks like. As a total novice having run just one hole in a few minutes.

I selected this video on "YouTube".
Of all the videos of "jackleg drilling" on "YouTube", this is closest by a long way to the mentoring I received.

2021 Women's Jackleg Low Hole
Mines Mining Team
(Colorado School of Mines)
[current link December 2023 *> - given "YouTube" links are reassigned periodically]

• they are deliberate but effective
• there is teamwork between the two drillers
• they are drilling accurately at on the target spot
• they are accurately drilling horizontally
• they are aligning parallel to the reference hole (the hole into which the broomstick is placed)
• they are letting the drill do the work, feeding at its own rate (leaning on the drill is not sustainable long-term, can only be done at one height - and is non-optimal so gives little if any advantage)
• they are controlling it so the drill doesn't bounce-around

They are close to the ground - hence the leg has to locate on the mesh.
Whereas I was drilling at chest height - easier and leg can just stab into the dirt floor.
So what they are doing in this drilling competition is a deliberately more difficult task than I was doing.

What I can say though - the sound in a tunnel in hard granite is at least ten times more than this where they are at the surface in the open!

The point of this drilling is to make the pattern of holes into which you insert the explosives to tunnel...

(R. Smith, 27Dec2023 (07Dec2023 text))