BBC's Further Update: The Rescuers Will Now Widen The Vent Shaft, From Overhead -- Vertically, With The Borer -- And Possibly Lift The Men Out One By One...

Due to how unstable the mountain's rock is, on the horizontal plain where the roadway tunnel was being cut, multiple attempts to reach them by the way they went in, have failed. And while the company is saying they will only need to cut a few hundred feet, the reality may well be that a vertical shaft near the men, at lower altitude, will still hit lots of fractured / highly unstable rock, and thus be prone to collapse -- very much like the horizontal tunnel, at the known collapse point. [It is not known how many hundreds of feet of the tunnel have collapsed. . . so that could be hundreds of yards of what we used to call. . . "bad rock".]

And so, it is my assessment that the only way to be sure that the vertical, or near vertical, shaft won't collapse in on these modified rescue efforts. . . is to go to the most stable point (likely far nearer the mountain top) and drill straight down. Moreover, many of the 40 missing may be very young -- boys, in fact -- as young as 15.

But of course, now that rescue would involve drilling down vertically, perhaps as much as some 2,480 feet (756 meters) from the top of the mountain, from above. And, my experienced guess is that to bore through almost a half mile of rock. . . will likely take three to four weeks, even with 24/7 shifts. [It is a matter of pure geological physics that a vertical shaft, even through bad rock, need only avoid side to side swaying forces (much rarer), and need not worry about overhead burdens, into the hundreds of millions of tons.]

So, not unexpectedly, families of the trapped men, in the Himalayas of northern India are voicing great discontent -- at the mouth of the tunnel, per the Beeb -- BBC:

. . .Also on Saturday. there was an angry confrontation between rescue officials and colleagues and friends of the trapped workers.

Tensions ran high as officials were challenged about the lack of progress. One man cried out: "It's been seven days and my brother is trapped in there."

Rescuers responded by saying they were spending sleepless nights to reach the workers. One official said the boys in the tunnel were like his own children: "I go to my bunk at night and cry as well. I can't cry in front of you otherwise you will lose hope."

The Silkyara tunnel in Uttarkashi district is part of the federal government's ambitious highway project to improve links with famous pilgrimage spots in Uttarakhand.

The mountainous state, where several Himalayan peaks and glaciers are located, is home to some of the holiest sites for Hindus. . . .

And all of that. . . before we consider that this may involve drilling into what Hindus regard as a sacred deity-infused mountain -- from above. Do stay tuned, but starting a drill at too low an altitude will likely lead to more failures, in reaching the men. That's my assessment. . . at least. Onward.

नमस्ते