Cable Saw

Cable Saw

 

a device for cutting stone in which the cutter is a cable 3-6 mm in diameter. Cable saws are used in quarries to cut blocks from the rock of a mountain massif and in stone-working enterprises for the manufacture of facing blocks.

The stone is cut by a nonfraying steel cable up to 1, 500 m long. A slurry of water and grains of an abrasive substance is fed continuously into the cut under the cable. The cable is driven by a pulley at the drive station; constant cable tension is maintained by a tensioning device. The cable moves at a speed of 7-11 m/sec. Among the abrasives used in cutting are quartz sand, for cutting rock of medium hardness (such as marble), and carborundum, for cutting very hard rock, such as granite (under workshop conditions only). The cable is supported over its entire length by a system of pulleys. Vertical operating motion of the cable (in the saw cut) can be produced by the use of stands. Such stands have provisions for moving the pulleys. A cable saw can produce a saw cut up to 50 m long. The depth of the saw cut is usually about 3 m; however, this depth can be increased by the use of higher saw stands. The speed at which the cable cuts a stone depends on the hardness of the stone, the degree of cable wear (as the cable wears, it entrains less abrasive), and the properties of abrasive materials. When quartz sand is used to cut marble, the cutting speed is 3-15 cm/hr; when carborundum is used to cut granite (under workshop conditions only) the speed is about 5 cm/hr.

A design aimed at future improvement of the cable-sawing process incorporates cutters made from a hard alloy or enclosed in diamond armor and attached to the cable. Cutters made of hard alloys are capable of cutting limestone with an ultimate strength of 15 meganewtons per sq m, or 150 kilograms-force per sq cm, as well as gypseous stone and other soft stones; diamond cutters are capable of cutting marble.

Cable saws are widely used in mining marble, travertine, and other rocks consisting of carbonaceous compounds, in areas with a warm climate. In areas with a long winter cable saws are less useful because of the freezing of recirculated water. A cable saw is capable of producing curved cuts because of the small diameter of the cable and therefore is frequently used for the construction of monuments and production of complex architectural components.

A. M. ORLOV