On Sun, 17 Jul 2016 11:44:37 +0100, Chris Hogg wrote:

snip

[1] I think he said the Company cutting the hole quoted for some 2
weeks of work and it took more like 8! ;-)

Dimension stone is cut in much the same way. Although large diamond
saws are now widely used, for the largest pieces they use a long wire.
In times past, the wire was passed through a bath of sand that acted
as the abrasive, but these days the wires have silicon carbide or
diamond-impregnated ferrules along their length. See
http://tinyurl.com/hogxeko

It's funny they look just like big bench bandsaws. ;-)

http://tinyurl.com/6wo55oq and scroll down,

Interesting.

http://tinyurl.com/zjh4fll

Gnarly. ;-)

and http://tinyurl.com/zd7q6cy

Yeah, the right hand diagram is what I believe they did on the SNB
exit.

If you were cutting a plane through a rectangular block using a 'loop'
driven from one side, I wondered how the cutting wire would cope with
the initial 'corners' opposite the driven side of the loop? Like, I
wondered if you might initially use an idler pulley (or two) on the
undriven side to initially get the wire to 'round' the corners and
then the idler could be removed and the loop drawn trough?

Cheers, T i m