Research Project

Despite national and international regulations on the protection of workers at risk of falling 1.8 m or more, falls from heights are still a primary cause of death for construction workers. They are also the second biggest cause of accidentrelated costs ($388 million per year from 2005 to 2007) and accounted for 21% of workrelated fatalities in 2009 (approximately 6,000 falls from heights each year).

Horizontal lifeline systems (HLLSs) are an inexpensive and effective way to protect workers against falls from heights. Designing them is a complex problem, however, due to the dynamic nature of the load and cable sag.

The IRSST has already published a technical guide to designing horizontal lifeline systems (Report T-18 / In French) for the use of engineers. However, a number of the documents and standards it refers to have since been updated, withdrawn or rewritten.

The purpose of the project Update of the technical guide to designing horizontal lifelines was to update the guide by developing a new calculation method that takes into account anchorage rigidity and updated standards, producing new calculation graphs and validating the new method through dynamic fall testing.

Full reference for the report resulting from this project

Galy, Bertrand, and André Lan. Conception des cordes d’assurance horizontales pour la protection contre les chutes de hauteur. Études et recherches/Rapport R-902. Montreal: IRSST, 2016, 91 pages.


We would like to thank the people and organizations who took part in the preliminary consultation for the development of this site, including the members of the follow up committee, Yohann Aubé, GESTESS, Stéphane Desjardins, APCHQ, Isabelle Dugré, ASP Construction, Bertrand Gauthier, CSN Construction, Pierre-Luc Labelle, CNESST, Martin Lemieux, SQC, and Simon Lévesque, FTQ Construction. Their contributions were extremely valuable.


Calculation software development and programming

Bertrand Galy, Eng, MEng construction engineering, PhD engineering


François Ouellet, IRSST
Linda Savoie, IRSST

Site development and programming



James Cookson et Karin Montin, s.e.n.c.