MARBLE BLOCKS CUTTING
A precise description of the oldest cutting technique is contained in a passage by Pliny the Elder (Nat. Hist. I, XXXVI): once the quadratari had squared the blocks, the sectores serrarii shaved slabs from the blocks using an unserrated iron blade which was “mounted on three boards and wedged permanently into the marble. This blade succeeded, with the help of dripping wet sand and who knows how much time, in sawing it.” This technique remained in use until the second half of the 18th century, when water-driven sawmills came into use (in the timber industry these sawmills had been active since the 15th century), the first of which were built by Count Giulio Lazzoni in 1759; by the Counts Del Medico, Monzoni and Lodovici in 1781; and by the Counts Luciani and Fabbricotti in 1783.
“The entire benefits of that new system came down to a slight economy of labour, which was in part replaced by a perfectly simple mechanism whereby, via a wheel turned by a waterfall, a single blade supported by a vertical gangsaw of the old model worked up and down the marble.”
Not until a later period did a Carrara engineer invent a cutting gang saw with several blades working the same way.
With the introduction of the steam engine, production increased rapidly: in 1926 no fewer than 220,000 tonnes of marble were sawn.
Hemp-suspended gantries with 40 blades could cut a thickness of 16-18 cm in 24 hours; the screw-driven kind (suspended from steel rods) 22 cm.; and self-powered gantries 25-30 cm..
This last technique, the self-powered gantry, marked the real starting point for all subsequent advances in marble cutting technology.
Refinements in marble working technology continue to this day. Multiblade gantries with diamond-point cutting edges, vertical cutters, diamond-point cutters, and bridge cutters: these and other machines can now be located directly in the quarry, in many cases revolutionizing the working process.