Note

This manual is written for the technical staff of companies that have to design systems providing protection against falls; these systems consist of horizontal lifelines. It describes these systems’ principles of design and allows us to understand the magnitude of the forces involved. The forces that the horizontal lifelines apply to anchors is very high. Consequently, experienced technical staff must be in charge of the design process, the manufacturing and installation plans and the operating mode. Everything must be SUPERVISED AND APPROVED BY AN ENGINEER.

Paragraphs 2.10.12.3.d (i) to (iv) of Quebec’s Safety Code for Construction Work describe the minimum requirements of a system of horizontal lifelines whose design does not require the supervision and approval of an engineer.

This technical manual on the design of horizontal lifelines consists of six parts:

• The first describes a simplified approach to analyzing the problem;
• The second is a description of a shock absorbing device for a horizontal lifeline, "latchway" and rail;
• The third is paragraph 2.10.2.3 of the Safety Code for Construction Work; it was adopted by a review panel, appeared in the Gazette officielle du Québec and deals with horizontal lifelines;
• The fourth is the set of nomograms developed on the basis of parabolic analysis and paragraphs 2.10.2.3.d (i) to (iv) that facilitate the design and verification of horizontal lifeline systems;
• The fifth is the set of conclusions from the results of tests carried out by Ontario Hydro based on which nomograms allowing us to graphically design horizontal lifeline systems were developed. The interested reader can consult these nomograms in the report by A.C. Sulowski et al (Report 83-294-H, Ontario Hydro);
• The sixth is the annex in which all the theoretical studies are explained in detail, and a summary of the main results of tests carried out by Ontario Hydro on various combinations of horizontal cables; it presents empirical evidence that supports the detailed analyses that could be carried out by engineers.