An incident involving a 76ft telescopic boom lift, which the contractor described as an uncontrolled platform descent on a Winvic site in the UK earlier this week, has been confirmed as a one off isolated incident resulting from human error.
A man was using the lift, a Zoomlion ZT23J telescopic from the Hire Safe Solutions fleet, which has a 25.1 metre working height, to install cable tray containment to the underside of roof beams/purlins, working in conjunction with a large Dingli scissor lift.
The lift, which is, we are told, relatively new, suffered a sudden hydraulic failure, causing the almost fully extended boom to drop suddenly in two to three metre increments, until the platform came to rest on the chassis of the scissor lift, oddly causing the lift to tip rearwards as if the boom was under a pressurised descent.
The incident shortly after it occurred
The man on the platform suffered some minor injuries - bruising, etc. - and was taken to hospital for a check over and was given the all clear.
The contractor, Winvic issued a safety alert on Tuesday and ordered the use of all Zoomlion boom lifts on its sites to be suspended, indicating that it published before checking what had caused the incident. Needless to say, the bulletin has been widely circulated, causing reactions on other sites and with other rental companies.
The original notice
Today, Winvic issued a follow up notice stating that after investigating, the incident was caused by a rare one-off issue that followed a lift cylinder replacement.
The follow up incident report The notice says:“This occurred due to a 'transportation seal' being left attached to a replacement 'primary boom cylinder', in turn, this created a weak point for the pressurised system to exploit. The works to replace the component had taken place prior to the MEWP arriving on a Winvic site. The MEWP had been subjected to the necessary inspections up to this point also.”
“The transportation seal is essential to maintaining the integrity of the component during storage, transport etc. Protecting it from abrasion, contamination and other elements that could affect the system throughout its life cycle.”
Key Failings
“Although the works were carried out by an approved and competent person, the seal was not removed as instructed within specification.”
“The task of such replacement is rare, with 517 Zoomlion boom type MEWPS in circulation in the UK, this one being the only one to require such replacement. Experience of such issues potentially being limited.”
As a result, the stop notice was rescinded, but in the meantime, the original notice has caused a fair bit of disruption.
Vertikal Comment
It is good to see Winvic following up relatively quickly on its original notice in this incident, which could easily have been more serious.
However, it is a shame that it did not hold off a little before circulating the original notice. It is, of course, possible that the cause of this incident could have been more than a one off/isolated issue, and it would not have been forgiven if it had held off informing people, and another lift had gone down in the same way, causing a fatality.
Another positive in this case is that the social media trolls did not go ‘hog wild’ with reporting and spreading oddball inaccuracies, as they did when a scissor lift incident occurred on a Winvic site in Northampton last year. In that case, some contractor staff and others circulated a stream of totally false and, in some cases, libellous claims/facts, while Winvic said nothing and refused to talk. This might have contributed to its decision to publish this notice so promptly? That and the fact that no one was seriously hurt.
So, there are two sides to this sort of thing, one is that circulating a rapidly produced report can sensationalise a simple one-off human error, causing unnecessary panic/reaction on other sites. Or it may well have prevented others from telling the story with false ‘facts’ and theories?
What would have been nice is if, after a quick initial inspection of the machine, it had said: “This looks as though it might be a one off issue, and we are investigating further.”
Easy to say, though, when you are not directly involved.
o
FAO Mr Ian Goodhead - Safety Director,
Winvic Construction Ltd
Brampton House
19 Tenter Rd,
Northampton. NN36PZ.
Dear Mr Goodhead,
Thank you for your prompt attention to this AWP Un-controlled Descent Incident depicted above, as the Operators Basket dropping on the Scissorlift depicted, had the potential be very serious.
Your speedy Report on both the Root Cause and the Remedy to this incident is also to be applauded, as all others need to know of these actions to avoid any repeat of this Failed Hydraulic Seal.
By the way, your Un-controlled Descent of a Hydraulic system is not the first, as there have been many over the years, which is precisely why the Manufacturers started to fit ‘Check Valves’, to restrict the backflow of Hydraulic Oil and thus protect all Operators Safety, while working at Height.
Thank you again for your Open and Honest Report, because Worker Safety is important, Very Important and much too important to leave it to chance, or to a defective Seal ?
Yours Sincerely
Mike Ponsonby
Safety Trainer 1997 to 2026.
o
FAO Mr Ian Goodhead - Safety Director,
Winvic Construction Ltd
Brampton House
19 Tenter Rd,
Northampton. NN36PZ.
Dear Mr Goodhead,
Thank you for your prompt attention to this AWP Un-controlled Descent Incident depicted above, as the Operators Basket dropping on the Scissorlift depicted, had the potential be very serious.
Your speedy Report on both the Root Cause and the Remedy to this incident is also to be applauded, as all others need to know of these actions to avoid any repeat of this Failed Hydraulic Seal.
By the way, your Un-controlled Descent of a Hydraulic system is not the first, as there have been many over the years, which is precisely why the Manufacturers started to fit ‘Check Valves’, to restrict the backflow of Hydraulic Oil and thus protect all Operators Safety, while working at Height.
Thank you again for your Open and Honest Report, because Worker Safety is important, Very Important and much too important to leave it to chance, or to a defective Seal ?
Yours Sincerely
Mike Ponsonby
Safety Trainer 1997 to 2026.