beautifull exemplary, in that site where I posted the first discussion, in the 1940s, 1930 worked a primordial mechanical excavator with cables and chains, of Italian brand, I was told by my uncle who went into the quarry to see her work
http://www.cema.or.jp/general/ayumi/pdf/cema4.pdf
http://www.cema.or.jp/general/ayumi/pdf/cema4.pdf