STEEL CABLES
The modern demands of industry for speed and large capacity have called for strengths exceeding that possible to attain from hemp or manila ropes, which are not excessive in size or cost. As a result, steel ropes and cables have been developed and perfected to a high degree of strength and dependability. The majority of hoists and cranes use steel rope. Logging industries depend for most part on steel cables. Cable cars use special steel cables which in many cases are several miles long. Long tramways use light steel cables, for long spans where manila rope would scarcely maintain its own weight. High speed passenger elevators maintain safe and dependable service day after day only through the strength of the perfected flexible steel cable. However, as stated above, each particular type of service calls for some special type of cable. The following tables are not complete but will serve to indicate the scope of the field covered by this subject.
Composed of 6 strands and a hemp center, 7 wires to the strand
Composed of 6 strands and a hemp center, 19 wires to the strand
Composed of 6 strands and a hemp center, 37 wires to the strand
Six strands of 7 wires each—hemp center
6 strands of 19 wires each—hemp center
Six Strands—19 wires to the strand—One hemp core
in tons of 2,000 pounds