A welding fault is responsible for the collapse of a crane in downtown Halifax during post-tropical Storm Dorian, according to a new report from the Nova Scotia Department of Labor.
During their investigation, the security department told the department that a welded section about six to nine meters above the mast base was severed when the crane was hit by gusts of wind at speeds of up to 107 km / h on September 7, 2019.
The weld failure “transferred the weight carried by the mast’s four vertical posts to only three of its posts, causing the tower section to rotate and fail, resulting in the complete collapse of the crane,” the report said .
The crane owned by Lead Structural Formwork Ltd. of Moncton, NB, owned and operated by, crashed into a 13-story building under construction on South Park Street, causing significant damage to the top three levels.
An adjacent building was also damaged when the crane hit the top corner and a balcony. Counterweights from the tower crane fell on the street.
Localized state of emergency
No one was injured in the collapse, but the area – a mixture of houses and shops – had to be evacuated. Some businesses had to remain closed when their entrances were inaccessible and lost significant revenue.
The provincial government announced a localized state of emergency and said the measure was necessary to ensure the quick and safe removal of the crane. The province covered the $ 2 million bill to get the job done ASAP and the area reopened to the public.
Work to safely remove the tower crane and debris from the building was completed on November 4, 2019.
Cranes should withstand stronger gusts
According to the report, the fallen crane was a Manitowoc model Potain 8520Ps. In general, tower cranes are designed for wind speeds of 150 to 160 km / h. On the day of the storm, winds with gusts of 97-107 km / h were recorded as being much lower.
On June 4, 2019, the provincial safety department was informed by the general contractor that the turntable at the top of the tower crane had got stuck to prevent it from disappearing “due to the weather” – basically spinning freely in the wind when not in use .
The contractor informed the province that the upper part of the crane, consisting of the cab, turntable and boom, would be repaired or replaced as soon as possible to eliminate the inability to rotate freely. The repair was carried out on June 7, 2019.
The crane operator met the requirements
The investigation found that Lead Structural Formwork is in compliance with legal and regulatory requirements to prevent the event from occurring and that no further action will be taken in relation to the collapse.
The crane collapse made headlines across the country, inspirational memes, Halloween costumes – even the name of the building at the center of the accident. The crane opened a year behind schedule. (Olympus properties)
The province recently said the Department of Labor will meet with all tower crane owners and operators in the province and require that all crane masts be thoroughly cleaned, inspected and tested to identify any defects or possible deterioration.
Several companies hit by the collapse have filed class action lawsuits against WM Fares Architects Inc. and WM Fares & Associates Incorporated, the developer of the building that was under construction at the time the crane was overturned, to make up for lost sales. The lawsuit also cites Lead Structural Formwork and the Manitowoc Company.