OHS Code Explanation Guide

Published Date: July 01, 2009
Bookmark this page

Part 21 Rigging

Section 301 Ferrules

Subsection 301(1)

In a wire rope, a splice is made by joining interweaving strands or by overlapping and binding. Three types of common splices for creating an eye loop are the Flemish eye splice (see Figure 21.15), the tuck splice (see Figure 21.16), and the fold-back splice (see Figure 21.17).

Figure 21.15 Example of Flemish eye splice

Figure 21.16 Example of a tuck splice

Figure 21.17 Example of a fold-back splice

A splice can be covered by a clamp (see Figure 21.18), a pressed sleeve or ferrule (see Figure 21.19), or wrapped with wire serving (see Figure 21.20).

Figure 21.18 Example of a splice covered by a clamp

Figure 21.19 Example of a pressed sleeve

Figure 21.20 Example of a clamp wrapped with wire, serving

The most common splice is the Flemish eye splice with a pressed (swaged) ferrule. Swaging is the process of applying great pressure such that the metal of the ferrule flows into the crevices between wires and their strands. This makes a permanent bond and develops almost 100 percent of the breaking strength of the rope.

The ferrule is not covering the entire splice if splice ends are visible. To ensure adequate strength, the ferrule must be of steel and properly swaged onto the splice. When a Flemish splice is used to form an eye loop in a wire rope, the steel ferrule must identify the splice as being a Flemish eye splice.

Subsection 301(2)

Aluminum alloy ferrules are not suitable if exposed to temperatures greater than 204° Celsius or where caustic conditions are present. To avoid the possibility of aluminum alloy ferrules being used under such conditions, they must be identified as made of aluminum alloy and must be commercially manufactured and properly swaged onto the splice.

Commentary about “commercially manufactured”

In general, a commercially manufactured product has the following qualities

(a) it is designed and built to some standard or generally accepted engineering principles that make it safe for use;
(b) it is designed and built by person(s) with the skill or competence to be able to make the product safe;
(c) it is produced with the intention of being generally available to anyone who wants to buy it – normally there is an exchange of money;
(d) it is normally supported by the manufacturer with a warranty, guarantee, and product support; and
(e) liability and safety issues related to its use have been addressed by the manufacturer.

It is implied by the OHS Code, that a product that is “commercially manufactured” is “safe” because it has been produced by a “manufacturer” that has the skills and competencies to do so.

Criterion (a) refers to the product being designed and built to some “generally accepted engineering principles”. It is expected that a “manufacturer” is able to provide drawings or sketches of the product that include an assessment of the product’s strength, load-bearing capacity, etc. Further, criterion (d) mentions “product support”. This may include, among other elements, the availability of written manufacturer specifications.