First ever go with a rock-drill 07December2023 - Condurrow mine.
Identified which variant of Holman rock-drill it is 21December2023 - while at Geevor mine museum.
Here it is:
Holman Silver 900
This is a powerful rock-drill for drilling hard granite.
The "Holman Silver 303" is the regular size and power.
The "Holman Silver 900" is described as being able to drill at about a
foot a minute - about 30cm per minute - in hard granite.
My own observation accords with this - drilling 1.5m in hard granite
took a few minutes.
(R. Smith, 24Dec2023, 26Dec2023 (rate))