Wire Ropes, Elements and Definitions - Wire Ropes: Tension, Endurance, Reliability - page 34

Fig. 1.30 Rope usage
classification

running rope stationary rope

track rope rope sling

the rollers of cabins or other loads in aerial ropeways and cable cranes. In contrast
to running ropes, track ropes do not take on the curvature of the rollers. Under the
roller force, a so called free bending radius of the rope occurs. This radius
increases (and the bending stresses decrease) with the rope tensile force and
decreases with the roller force. Wire rope slings are used to harness various kinds
of goods. These slings are stressed by the tensile forces but first of all by bending
stresses when bent over the more or less sharp edges of the goods.

1.5.2 Wire Rope Constructions

There are many different constructions existing for wire ropes. An overview of the
different classes is presented in Table 1.6 .
Spiral ropes. In principle, spiral ropes are round strands as they have an assembly
of layers of wires laid helically over a centre with at least one layer of wires being
laid in the opposite direction to that of the outer layer. Spiral ropes can be
dimensioned in such a way that they are non-rotating which means that under
tension the rope torque is nearly zero. The centre of the spiral rope is usually a
wire but it can also be a parallel lay strand. Examples are shown of the three basic
types of spiral ropes in Fig. 1.31 .
The open spiral rope consists only of round wires. The cross-section of a spiral
rope 1 9 37 is shown as an example in Fig. 1.31 with the numbers of wires
1 + 6 + 12 + 18 in the three wire layers. The half-locked coil rope and the