CIM Bulletin, Vol. 97, No. 1083, 2004
In 2000, CANMET-MMSL was engaged by the Ontario Ministry of Labour (OMOL) to conduct a study of the practices, in several key mining jurisdictions, of determining the criteria that are used to decide when the wire ropes used in mine hoisting are to be retired from service. Subsequently, the author visited key officials and institutions in North America, Europe, and Africa. Material from Australia was also included.
The report that resulted included, among other sections: (1) the history of wire ropes and trends in manufacturing technology; (2) the mine hoisting practices; (3) the requirements regarding safety factors; (4) the various operations and their inspection practices; (5) the criteria for rope replacement; (6) potential future developments that could take place in Canada; and (7) recommendations.
Subsequently, the report was issued by OMOL, and as a CD-ROM by CANMET-MMSL. In this paper, the author presents the key findings and the recommendations made in the study.
A brief summary of the conclusions in the report are: (1) visual inspections, while essential, are often neglected; (2) destructive testing is essential; (3) non-destructive tests are also essential; (4) the quality of the rope is utterly dependent on the way in which it is used (and abused); (5) we need to examine all of the criteria which are used to determine if a wire rope should be rejected, and of the means that are used to enforce these decisions. Separate criteria must be developed for each major type of rope construction used; and (6) standards should be developed for all aspects of the manufacture, use, and evaluation of wire ropes.
From these, the following were developed as recommendations:
Until it has been demonstrated that there are clear redundancies between the criteria used in judging whether or not a mine hoisting rope should be rejected, all of the criteria in the Ontario Regulations should be retained.
There should be a continuing compilation and assessment
of the wire rope retirement criteria used in the major mining jurisdictions. The exact relationships between these should be established.
Since inter-strand nicking, wear, and corrosion will likely be different for each type of wire rope construction, separate retirement criteria should be established for each.
Standards should be developed for all aspects of wire rope inspection practices, including the manner in which these are to be performed and the conditions, which are provided by mine operators.
Standards should be developed in respect of all of the tests and means of evaluation, which are required to determine whether or not a wire hoisting rope should be discarded.
Standards should be developed for the training of wire rope inspectors to levels deemed to be acceptable to the regulators.
Consideration should be given to the development of a Canadian code of practice for the design, operation, and inspection of mine hoisting plants. In this respect, the province of Ontario might wish to lead in the formation of a task force, on which parties from other jurisdictions wishing to participate could be invited to participate.