Why aerial work platforms hurt people

Mobile elevating work platforms, usually called MEWPs or elevating work platforms in Canada, have replaced ladders and much scaffolding for short-duration work at height. Scissor lifts, vertical mast lifts and boom lifts let a worker rise to a ceiling, a façade or a light standard in seconds, inside guardrails, with tools and materials close at hand. Used well, they are one of the safest ways to work at height. Used badly, they fail in a small number of predictable ways, and when they fail the result is often a death.

This course is awareness and supervisor training. It explains how MEWPs hurt people, what the law and standards expect from owners, employers, supervisors, operators and occupants, and how to plan, inspect, set up and use a platform so that those failures do not happen. It is written for site supervisors, foremen, facility managers, safety coordinators and workers who use or work around MEWPs.

It does not qualify anyone to operate a MEWP. The CSA B354 standards and Ontario's O. Reg. 213/91 require operators to be trained on the class of platform they use, to receive oral and written instruction, and to be familiarized with the specific machine before they operate it. Workers who may rely on fall protection on an Ontario construction project also need working at heights training from an approved provider under O. Reg. 297/13. Completing this course is one part of that picture, not a substitute for it.

How MEWPs fail

Investigations of MEWP deaths around the world keep finding the same five events. Learning to recognize them is the first step to preventing them, because almost every control in this course is aimed at one or more of them.

Note that very few of these events are caused by a machine suddenly breaking. Most come from where the machine was used, how it was set up and what the people on it did. That is why supervisors, who decide where and how platforms are used, have as much influence on MEWP safety as operators do.

What the numbers show

The International Powered Access Federation (IPAF) collects reports of fatal and serious MEWP incidents from member companies and authorities in more than 20 countries and publishes an annual global safety report. The reports undercount, because reporting is voluntary and some countries contribute little data, but they show the pattern clearly.

Earlier research in the United States found the same mix. A NIOSH analysis of aerial lift deaths from 1992 to 2003 found more than 300 deaths across all industries. For scissor lifts, tip-overs and collapses caused more than half of the falls; for boom lifts, tip-overs and collapses, falls from the basket and ejections each accounted for roughly a quarter to a half of the deaths, and many of the people who died were not using fall protection.

Canada does not publish a single national count of MEWP deaths. Provincial ministries, workers' compensation boards and safety associations such as IHSA in Ontario and the BC Construction Safety Alliance publish incident summaries that show the same events: workers crushed against ceiling structure, platforms overturned on slopes and soft ground, and booms contacting power lines.

The energy behind a fall or overturn

People sometimes think of a scissor lift as a small, slow machine, and at ground level it is. Elevated, it is a heavy mass on a narrow base with a worker standing several metres in the air. When it tips, the platform swings through an arc and the worker hits the ground at high speed, often with the machine landing on top.

In an overturn the worker does not simply fall from the platform height. The platform rotates about the tipping line, so its speed at the moment it hits the ground can be higher than a straight drop from the same height, and the worker is often flung outward. This is one reason the standards put so much weight on stability controls, tilt alarms and staying within the manufacturer's limits, rather than relying on guardrails alone.

Applying the hierarchy of controls

The hierarchy of controls from HSE-103 applies to work at height on platforms. A MEWP is itself a control: it replaces ladders with a guarded platform. But the choice of platform, and how it is used, still follows the hierarchy.

The example shows a common pattern. Choosing the right platform removes some hazards and leaves others. A supervisor's job is to see the hazards that remain and put controls on them before the work starts.

What this course covers

The lessons follow the life of a MEWP job. Lesson 2 sets out the law, standards and roles. Lesson 3 describes the types of platforms and the features that keep them safe. Lessons 4 to 6 cover planning, inspection and set-up. Lessons 7 to 10 cover fall protection, safe operation, electrical and weather hazards, and special applications. Lesson 11 covers emergency lowering and rescue, and lesson 12 brings everything together in a safe use plan for a real-world job.

Related HSE courses cover topics that overlap with MEWPs: HSE-212 for fall protection theory, anchors, clearance and suspension intolerance; HSE-218 for forklifts, including platforms lifted on lift trucks; HSE-219 for cranes and the full tables of limits of approach to power lines; and HSE-224 for the electrical background to arc and shock hazards. Where those topics come up, this course gives what you need for platforms and points you to the deeper treatment.

A note on words

Different documents use different names for the same machines. Ontario's construction regulation says elevating work platform, the CSA standards say mobile elevating work platform or MEWP, and many workers say scissor lift, man lift or boom lift. This course uses MEWP for the machines in general and names the specific type when it matters.