People living around the port of Carrara, in Tuscany, Italy, are used to seeing giant slabs of the region’s signature white marble moved onto ships bound for every corner of the earth. But in the dead of night late in June, they witnessed an even bigger spectacle — a slow-moving, 3,500-ton turbogenerator built by Baker Hughes, a GE company (BHGE), headed for western Kazakhstan, where it will be one of five generators providing power to the Tengiz oil-extraction project.