Ann: Project update, page-18

Use of Non-Explosives.
This Product would be similar if not the same NTL may be making enquiries about.
https://www.expando.com.au/what-is-expand

From 1st hand experience back in my Building days, I used this exact or similar brand material, in removing rocks adjacent to an Office Building, where as traditional explosives could not be used within approximately 2 x metres of the Offices.

For memory we had to extract a rock 'By Hand' ie (Pick and Shovel) only, in which was a couple of square metres in diameter.
Drilled about 15 or so holes in a few hours, filled up with the powder, and then the powder worked it's magic overnight.
Probably took 2 of us the best part of the day next day to extract rock and then bin it close by.
So worked a treat, plus NTL would have heavier machinery to help the extraction process.