A miner, (prob cornish, acid.) weighs in his view on the tunnel on the guardian comments section:
bobbymac1956 13h ago
11
12
Wow apart from anything else and as a coal miner with 40 years down the pit 36 of those heading out roadways this was some feat .
I wonder if the motorbike also doubled up as a compressor to power pneumatic picks (windy picks as we know them ) if so then they are very noisy and a mile long compassed airline would have to be steel pipe probably with a reservoir to maintain pressure , but in a tunnel that narrow theres not much room to swing a shaft ( a shaft is what miners call a pick) the actual surveying underground is very simple these men probably used a cheap laser , before lasers you would hang a flame lamp with a short flame and then line up from a fixed point down plumb lined string ( we used to re use detonator wire as it was fluorescent and we could drive tunnels many miles long and end up plumb on centre just by eye , this seems to baffle the authorities here but using a theodolite ( those things you see surveyors peering into set on tripods ) and a half decent surveyor working from a known point in the jail easy peasy really and done every day in mines everywhere . It is hard to tell but there are parts of the tunnel that look like they have been shotcreted ( fine concrete is sprayed under pressure again using air ) this to some extent binds the surface together and though it does not really do much to support the roof it aids ventilation , however as they where not really that deep (30 or forty feet where mentioned) weight would not be too much of a a problem so no need for steel or wood supports and of course providing they kept the tunnel narrow . They must have had some form of specially built rail way set to that narrow gauge , a tub on wheels ( a bathtub would do the job ) to hand fill into you would only really have room for one man with the pick and a man probably on his knees shovelling into the tub perhaps a couple of teams to keep going round the clock . Ventilation would not really be much of a problem given modern materials , a suction fan mounted in the house connected to say eight inch reenforced rubber hose , of the type you see used to clear drains and this works better than a blower fan for two reasons nature abhors a vacuum and it would help in clearing dust , imagine the end of a large vacuum cleaner with the nozzle fixed to the shoulder of the tunnel up by the miners head and keeps the rest of the roadway clear with a powerful enough exhaust fan conditions would not be too bad the flow of air cools you down .
So from his arrest last february till last week they did not do too bad over a mile and the plan must have been put in place as soon as he was imprisoned and to do it without raising suspicions , well maybe fear and i guess they earned a decent bonus . At the house used it would have been noisy but not more than a diesel engine running . How many men round the clock and taking turns at the face ? at least a dozen grafters on each three shifts still hard work but doable with the right gear .
totally OT here but wtf that's some mad shit
