Wire Ropes.
We have not completed the story of rope making. There is the wire rope to consider, a kind of cordage now largely used in many industries, in which it has superseded hemp ropes and chains. These seem to have originated in Germany about 1821. In the bridge at Geneva, built in 1822, ropes of untwisted wire, bound together, were used, and some fifteen years later “stranded” wire ropes were employed in the Harz mines. These at first were made of high-class wire, but only steel is now used in their manufacture. A strand of wire rope generally consists of from six to nine wires and sometimes as many as eighteen, but much larger ropes are made by twisting these strands together. They are generally galvanized to prevent them from rusting.
Stacking Bales of Manila Fiber with Portable Compressed Air Engine
Hank of Manila Fiber Twelve Feet Long
The applications of wire ropes are very numerous, an important one being for winding and hauling purposes in mines. For aerial ropeways they are extensively employed, and are of high value in bridge building, the suspension bridge being sustained by them. The strength of the steel wire used for ropes varies from seventy to over one hundred tons per square inch of sectional area, the weight of a hemp rope being about three times that of a wire rope of equal strength.