IRSST - Institut de recherche Robert-Sauvé en santé et en sécurité du travail

Protecting against Falls from Heights: Updated Guide and New App

  •   July 19, 2017

Montreal, July 5, 2017 ‒ The Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST) has updated its technical guide Protecting against Falls from Heights – Horizontal Lifeline Design. In addition, an online application that incorporates the main parameters required for designing horizontal lifelines has been launched.

The Guide

This new version of the guide reflects amendments made to the Safety Code for the Construction Industry that require a lanyard, which connects a worker’s safety harness to the anchoring system, to be equipped with an energy absorber. It proposes a new analytical method for designing horizontal lifeline systems (HLSs), which was put through 42 dynamic tests of falls from heights to study the influence of a number of parameters (span, anchorage flexibility, cable diameter, deflection, etc.) on horizontal lifelines, as well as through digital simulations and double validation. The tests showed that the experimental results were consistent with those obtained using the proposed analytical method.

Design App

HLLS Web app

Intended primarily for engineers specializing in the design of active fall protection systems, the app can be used to design horizontal lifeline systems (HLSs), also called flexible continuous anchorage systems. Incorporating the nomograms developed when the technical guide was updated and all HLS design parameters, the new tool offers a user-friendly way to calculate cable tension and deflection for fall arrest purposes, as well as the clearance required in relation to the cable. The app can also be used by prevention officers to check the compliance of an existing system, but it does not replace the expert opinion of an engineer.

“Even though under Quebec regulations, workers exposed to a risk of falling three metres or more must be secured, around 6,000 falls from heights occur every year in Quebec, and many of them are fatal. The guide and application will help engineers test the validity of their systems or certain working assumptions at the predesign or design stages or in the field. As a result, they will be able to perform their calculations faster and provide consulting expertise at lower cost. Prevention officers and Commission des normes, de l’équité, de la santé et de la sécurité du travail (CNESST) inspectors will also be able to use the guide and app to prevalidate installations. These resources could also be used in fall prevention training sessions,” says Bertrand Galy, an IRSST researcher and codeveloper of the application.

The online app can also be accessed from a mobile platform (tablet or smartphone). Along with the guide, it is available free of charge at


Jacques Millette
Manager of Public Affairs