This case involves a commercial painter who was severely and permanently injured when a construction lift he was working on tipped over. At the time of the incident in question, the worker was using the lift to access the side of a large commercial structure, which he was covering with a protective coat of paint. It was noted that the machine lacked stabilization struts, despite the fact that it was designed specifically for use at significant heights. The worker extended the lift to near its maximum recommended height when it suddenly tipped over, causing serious injuries.
Question(s) For Expert Witness
- 1. Please describe your experience in designing and/or testing industrial aerial lifts.
- 2. What design features could be used to prevent aerial lifts from flipping?
Expert Witness Response E-007551
I own a construction equipment inspection company and have inspected several aerial lifts. Hydraulic outriggers/stabilizers are what are used to prevent aerial lifts from flipping. “Better” aerial lifts have these in place at the time of purchase. For background, these outriggers/stabilizers come with the equipment itself. They are not purchased as an addition. They’re approximately 4 feet long and help stabilize the machine when it is on uneven ground or is bearing a considerable amount of weight. Most machinery involving height such as aerial lifts have outriggers or stabilizers. This model does not have such an outrigger or stabilizer and in my opinion, this is a major design flaw. This model does have a counterweight that’s intended to off-set the balance of the machine, but that is not sufficient to balance the machine, particularly considering that in reality, the machines are often on uneven ground.
Expert Witness Response E-009380
I served as Director of Product Safety for 10 years at a manufacturer of aerial lifts similar to the model discussed here. I am also the Chairman of the ANSI A92 committee for aerial work platforms, the committee that covers aerial lifts. I am very involved with creating ANSI’s standards and remain up to date on how they are changing. I am a member of several other subcommittees for aerial work platforms as well. I have been involved in investigating and reviewing numerous tip-over accidents. I will say that most tipovers are caused by driving off a drop-off or by operating on a slope. Often, in the slope scenario, the machine is on a side slope and the counterweight is rotated to the downhill side. Less common are tip-overs caused by gross overloading or collision. The design of this kind of platform is covered in ANSI and the prevention measures are: specific stability criteria, stability testing, tilt alarm, load rating, warning labels and training requirements.