Mystery hole digging drop tool - GIF

[Frank S]

I am wondering what kind of catch and release mechanism are they using there clearly are no electrical cables. The only thing to scale by wold be the block on the crane or the stabilizing tower struts. the block wold most likely be about 2ft across and 1 section of the struts wold be 10 ft this wold place it about 6 to 7 feet tall and possibly 30" in diameter.
It is obviously used for penetration through something What I wold have no idea nor wold I speculate the why of the operation. If they are simply using it to enlarge a bore hole then an overshot drill bit would have served that purpose if they are trying to break through a very hard strata then a 3 cone button bit with 20,000 to 30,000 lbs of drill collars would do that at about 135 RPM.
If their intent was to set piles then a hydraulic or diesel pile driver could do that as well.
the only thing I can think of for its use is to make a bore hole for piles or posts by the means of compaction. the slight amount of dirt we see would be just the amount that saw sloughed off the top of it when retrieving from the bore hole nowhere near enough to constitute a hole that had been previously bored by an auger or drill bit.
Most drop hammer drilling is done with a blunt elephant foot shaped bit attached to a long solid cylinder for the weight and directional stability.