Two construction firms have been sentenced after a crane collapsed onto a city centre apartment block in Liverpool, UK, paralysing the operator.
The 79 metre tall tower crane was on a hotel and apartment block construction project at Kings Dock Mill when it collapsed in 2009. The Health and Safety Executive (HSE) prosecuted the site's principal contractor, Bowmer and Kirkland Ltd, and structural engineering company Bingham Davis Ltd, following an investigation into the incident.
Both companies were found guilty of breaches of the Health and Safety at Work etc Act 1974 following a trial at Liverpool Crown Court by failing to ensure the safety of workers or residents, HSE said. Bowmer and Kirkland was fined £280,000 (US$ 420,000). Bingham Davis has ceased trading since the crane collapse and was fined a nominal £1,000 ($1,500).
HSE's investigation found that the crane's foundation could not cope with the forces generated by the crane. During construction of the foundation, both Bowmer and Kirkland Ltd and Bingham Davis Ltd agreed to cut away essential steel reinforcement bars from the four concrete foundation piles, so that the crane's feet could sit on top on them, HSE said.
The steel reinforcement was replaced with four steel rods in each pile, which reduced the forces that the foundation could withstand, HSE said. Judge Gilmour said he was satisfied that it was the removal of the reinforcing steel and the inadequate replacement of the steel rods that led to the foundation being overloaded and the crane collapsing.
Speaking after the hearing, Warren Pennington, the investigating inspector at HSE, said, "The circumstances leading to the collapse were a mess. Bingham Davis employees had no previous experience of designing the type of crane foundation used at Kings Dock Mill. Likewise, Bowmer & Kirkland's employees at Kings Dock Mill had no experience of building one. Both parties made disastrous errors that were entirely preventable.
"The original error was made by Bingham Davis Ltd, which failed to spot a basic mistake in its calculations for the loadings imposed by the crane. This created a material risk which had the potential to have led to a crane foundation being constructed that was not strong enough to hold the crane up.
"During construction of the foundation, Bingham Davis advised Bowmer and Kirkland to cut away essential steel reinforcing bars in the foundation piles and replace such with steel rods. The removal of such reinforcing steel resulted in the foundation being too weak to support the crane. The foundation was further weakened when Bowmer and Kirkland failed to ensure the adequate insertion of the replacing steel rods.
"Neither company did enough to check what the result would be of cutting away this essential steel reinforcement and replacing such with steel rods."
In conclusion, Pennington added, "HSE hopes this case sends a clear message to the construction industry in relation to tower crane foundations. Designers of such should be familiar with industry accepted guidance and follow it, unless they have extremely well thought-out reasons for not doing so. The role of the principal contractor is also crucial in managing the design process. Both principal contractors and designers should ensure that robust systems for design checking are actioned at all times."
Liverpool Crown Court heard that on 6 July 2009 the tower crane fell onto a partially constructed apartment block, across a road, and came to rest on the Chandlers Wharf apartments. Eight counterweight slabs on the crane, weighing a total of 56 tonnes, broke free and crashed through the roof and six floors of the building.
Crane driver Iain Gillham fell from his cab onto the roof of the apartments and through the hole created by the counterweight slabs. Gillham suffered multiple injuries, which resulted in his legs being paralysed. No one inside the building was injured. Residents were evacuated from the 64 apartments.
The Health and Safety Executive is Britain's regulator for workplace health and safety. It aims to prevent death, injury and ill health. It does so through research, information and advice, promoting training, new or revised regulations and codes of practice, and working with local authority partners by inspection, investigation and enforcement.