On day two of the inquest into the fatal 2020 Liverpool mastclimber incident, which killed David Bottomley, 53, and son Clayton, 17, HSE inspector Andrew Crouch took the stand to be questioned on the investigation into the incident. Click here for day one of the Inquest
He confirmed that the investigation had found that a small pinion shaft in the gearbox - which sits between the drive motor and brake and the main drive pinion - had fractured and failed on both drive motor assemblies, meaning that platform had lost both drive and brakes when the incident occurred.
A typical drive assembly drawing note that the failed pinion was in the gearbox, which is coloured in red, and the brake is coloured green- therefore So that the drive pinion had neither drive nor brakes
Crouch added the shafts must have failed at different times, indicating that the unit continued to be used after one drive motor and brake were rendered inactive. He stated that it was impossible to say when the first shaft had failed, and therefore how long the platform had been operated with a single drive motor and brake.
As to the cause of the failure he said that an HSE metallurgist had simply determined that it was due to "metal fatigue".
The findings highlighted the fact that rules regarding regular drive and brake tests had not been followed. Crouch stated that the manufacturer’s manual recommended carrying out a brake test at least every day as a bare minimum, and ideally before every ascent. He also confirmed that such a test would have revealed that one of the motor/brakes was not active, adding that the platform did not have a system installed that monitored how much power each motor was using, which could have alerted users to a potential issue, well in advance of the second failure. Stating: "If this system had been in place, this accident would simply not have happened?"
In summary the evidence so far indicates a woeful lack of of service and maintenance, while the failure itself may also point to a poor design, or the use of substandard materials.
The jury was also told that the mastclimber was made in China and branded TDT, confirming the initial reports we had received, and also confirming that that it was supplied and installed by Adastra.
Comments