The UK government has issued a Safety Alert regarding two models of JLG scissor lifts, after three lift tip-over accidents in four years killed five people.
JLG Industries Inc. no longer distributes the 500RTS and 400RTS, which are the subject of the Safety Alert by the UK Health and Safety Executive (HSE), JLG spokesman Jeff Ford said this week. He declined further comment.
HSE issues Safety Alerts only for “major faults that would result in a serious or fatal injury and where immediate remedial action is required,” the agency notes. HSE is the UK’s national occupational safety agency, comparable to the U.S. Occupational Safety and Health Administration.
The JLG alert follows HSE investigations into three fatal turnovers of the 500RTS that claimed five lives in four years in Europe.
Safety Feature Malfunctions
The 500RTS is equipped with an oscillating axle that allows the machine to be driven on uneven ground in the transport position. As soon as the platform is raised out of the transport position (by the scissor arms being raised off the chassis), the oscillating axle should lock, preventing further rotation of the oscillating axle. (See Figure 1.)
The 500RTS also has a lift/drive interlock system that deploys stabilizers when the platform is elevated about 6.7 meters (just under 22 feet). For the 400RTS, the threshold is 8 meters (about 26 feet). (See Figure 2.)
In all three fatal accidents, however, HSE said:
• The oscillating axle lockout valve failed as the platform was raised; and
• The lift/drive interlock system did not work, allowing the platform to be elevated above 6.7 meters without the stabilizers being deployed.
“In each of the three cases, this resulted in the [Mobile Elevating Work Platform] becoming unstable in use, and the scissor lift overturned, killing the occupants,” HSE reported.
The JLG 400RTS was not involved in any of the accidents, but it was included in the Safety Alert because its design is similar to the 500RTS. In fact, the warnings extend to any MEWP with similar oscillating axle lockout valves or lift/drive interlock systems, HSE said.
Testing, Bulletins Noted
All of the JLG accidents occurred as the equipment was being inspected or tested, but HSE said the same issues could affect regular operations and operators.
The Alert cites “the need to regularly maintain, inspect and test” safety-related equipment on MEWPs “and also specifically to remind owners, users and others involved in the use of JLG 500RTS and 400RTS scissor lifts of this need.”
HSE notes that JLG has issued two Field Service Bulletins—FSB 2-12-01 (in 2002) and FSB 108A3E (in 2008)—regarding the two models and urges owners to ensure that they have complied with the bulletins.
The Alert specifies eight required actions, including daily inspection of the oscillating axle lockout system and the lift/drive limit switch.
“Failure to undertake daily tests and inspections can result in safety critical faults going undetected and lead to potential for the MEWP to overturn, resulting in serious or fatal injuries,” the Alert says.
Individuals testing the 500RTS and 400RTS scissors lifts should do this from the ground first, using the ground controls, before using the platform controls, HSE advises.
Whenever possible, the agency adds, “testing of safety critical functions should always be carried out using ground controls first (where the operator is at lower risk) before carrying out tests from the platform.”
For more information, contact JLG Industries Inc. (Europe), Wright Business Centre,1 Lonmay Road, Queenslie, Glasgow G33 4EL, Scotland, United Kingdom. Phone: +44 (0)141 781 6700. In the U.S., individuals may contact Product Safety and Reliability Department, JLG Industries Inc., 13244 Fountainhead Plaza, Hagerstown, MD 21742. Phone: (240) 420-2661. Email: ProductSafety@JLG.com.