Steel Wire Rope (SWR) - Safe Working Loads (Figure 3:11)

3.15 Steel wire rope consists of a number of strands (usually six) with a fibre core. Each strand consists of a number of steel wires - the most common form of construction being 6/19 indicating six strands each of nineteen steel wires with a fibre core. During manufacture, wires and strands are either coated with lubricant to prevent corrosion and friction in the rope, or are galvanised. The size of steel wire rope (SWR) is measured by its diameter (D) in millimetres. Once again a rule of thumb method for calculating Safe Working Loads is given for use in the field in the absence of any manufacturers specifications.

D²mm x 8 = SWL in kg

eg.

New 14mm steel wire rope
14 x 14 x 8 = 1568kg

If a steel wire rope is sharply bent, the Safe Working Load must be reduced by 30%.

Fig 3:11 Construction of a 6 X 6 wire rope