WorkSafe Qld has recently reported an incident where a two-post vehicle hoist with a four-tonne capacity collapsed, dropping a 2.5-tonne vehicle after the anchorage system failed. Although no one was injured, the incident had the potential to cause serious harm. The hoist posts were secured to the concrete slab using five mechanical torque-controlled expansion anchors per post. All anchors failed in different ways, including pull-out, concrete cone failure and tensile failure of the bolt shank. Corrosion was also identified as a possible contributor.
Contributing factors
Anchor failure on vehicle hoists can result from multiple issues. These include poor anchor design or overloading, installing anchors in low-strength or inadequately reinforced concrete, or failing to follow manufacturer installation instructions (e.g. wrong hole size, depth, or cleaning practices). Two-post hoists can also apply significant pull-out and side-loading forces, especially if the vehicle’s centre of gravity is misaligned. Additional contributors include anchor corrosion (water from washing the floor remaining in the holes), cyclic loading during lifting, uneven floors reducing anchor effectiveness, use of unsuitable anchor types, and the absence of regular inspection and maintenance.
Action required – building, hoist, and anchorage selection
Where possible, hoists should be installed using cast-in anchors placed when the concrete slab is poured, as these provide better long-term durability. Before installing a hoist in an existing building, the concrete slab’s strength, thickness and condition must be assessed to ensure compatibility with the anchorage system specified by the hoist manufacturer. Expert advice is recommended where slab quality is uncertain or uneven.
Heavily loaded or large vehicles may be safer on four-post hoists, which place less pull-out force on anchors.
Anchor selection and installation
Hoist manufacturers must provide detailed installation instructions consistent with AS 1418.9:2024 Cranes, hoists and winches Part 9: vehicle hoists., including requirements for concrete strength, slab thickness, anchor spacing, edge distances, hole preparation, tightening torque and retightening procedures. Anchors must be assessed as suitable for safety-critical applications and designed to AS 5216-2021 Design of post-installed and cast-in fastenings in concrete. Installation should be carried out by competent, trained installers. Certain anchors (deformation, thin-sleeve, drop-in anchors and screw bolts) are not recommended due to poor performance under cyclic loading.
Chemical anchors must be installed strictly in accordance with manufacturer instructions, and corrosion-resistant anchors should be considered where water exposure is possible.
Maintenance
Regular inspections must be conducted by a competent person, checking for loose anchors, movement, corrosion, water ingress, concrete cracking and issues around packers. If the anchorage system appears compromised, the hoist must be taken out of service until assessed by a qualified engineer. A written report should document findings and necessary remedial actions, which may include replacing the concrete footing and anchorage system.
For further information on the above please refer to link on WorkSafe Qld’s site or contact our Workplace Relations team on 82912000 or WR @mtasant.com.au.
