Marine Chain Cable Guide
Manufacturing, inspection, testing & defect identification for marine chain cable
1. Introduction
The risk associated with chain failure, as well as the costs of replacement, mean that it is essential that welded chain cable is properly manufactured, tested and certified.
Stud link chain cable is a relatively high-strength steel compared with weldable structural steel. This is particularly true for grade U3 chain materials. In order to achieve the required strength, the carbon is increased and the correct heat treatment is therefore critical to achieving the required properties.
The composition of the steel used to manufacture chain cable necessitates care when welding these materials. Most stud link chain is manufactured by an automated flash butt welding process, and where studs are welded this is normally done manually. It is important that both processes are properly conducted according to Rule requirements, since the result of poor welding is a reason for rejection of the chain cable, as some of the examples in this guide show.
About This Guide
- Covers stud link chain cable, short link chain cables, and the more common fittings
- Concentrates on the flash butt welding process for chain manufacture
- Uses pictorial examples of imperfections — images are for guidance only
- Acceptance or rejection is to be in accordance with the Rules
The guide follows the flow of the manufacturing process. At each stage, the manufacturing process is briefly described, followed by a brief reference to survey requirements and the types of imperfections which may be encountered. Imperfections are collected together in the Defect Catalogue section.