A sheet of curtain wall glass fell 76 storeys from the newly completed Shanghai Tower today, shattering to pieces on the streets of Pudong’s busy Lujiazui Financial district.
While no one was killed by the plummeting panel, which may have been as large as 2.2 by 4.5 meters in size and potentially weighing up to 1,000 kilograms, the driver of a Tesla car has apparently complained of injuries sustained from the glass shrapnel which exploded onto Dongtai Road beside the 132-storey landmark.
The Shanghai Tower, which is China’s tallest building and the second highest in the world, was originally scheduled to open last year, but has been beset by delays due to reported safety concerns. Tenants who signed agreements to move into the government-built and developed supertall last October have still not officially been allowed to move in, although some tenants began working from offices in the structure last month.
Beware of Falling 1000 Kilo Pieces of Glass
The section of glass curtain wall fell from the building as workers from Shenyang Yuanda Aluminum Industry Engineering attempted to replace a damaged panel, the official Shanghai Daily said today, citing a statement from the Shanghai Tower
Such damage is common in inferior quality glass when it is subjected to changes in temperature, with Shanghai still experiencing mild weather during these initial days of May.
According to engineering documents from Gensler, which designed the unique dual-wall structure, the exterior glass panels on the building measure anywhere from 2.2 by 4.5 meters to 1.2 by 4.3 meters in size, and are made of laminated glass of up to 30 millimetres in thickness. The individual pieces can weigh anywhere from 800 to 1,000 kilograms, with the larger panels being used in the lower floors of the building.
Official Media Blames Accident on Maintenance Workers
Initial reports indicated that the section of curtain wall fell suddenly from the building without human intervention, and there was no service gondola visible in photos of the building taken immediately after the incident. However, the official account blaming the engineering contractor contradicts these early reports.
Shenyang Yuanda is reputed to be the biggest curtain wall contractor in China, however, an expert on replacing the oversized glass panels told Mingtiandi that today’s incident indicates that key safety procedures were not adhered to.
Safety Procedures Not Followed
“There is a 100% safe way to do this with correct safety straps and backup lines, but something was not followed correctly,” the engineering consultant said in the interview.
Given the absence of workers in an external gondola, our industry source, who previously oversaw the replacement of 6,000 exterior glass panels on Sun Hung Kai’s IFC project next to the Shanghai Tower, speculated that the contractor’s team may have tried to pull a damaged panel into the building using only suction cups, without first attaching straps to the giant glass pane.
Standard procedures would call for the replacement crew to use safety slings on the glass anchored to a column as backup, in case the main grip on the pane failed.
Other possible causes for the panel coming loose during replacement are that not enough workers were employed to maneuver the pane, or that the team lacked sufficient training or failed to account for wind forces.
China’s building boom and unevenly enforced safety standards have made falling curtain wall a semi-regular occurrence in Shanghai with buildings such as Plaza 66 on Nanjing Road also being known to shed giant panes of glass onto the streets below.
While still not officially open for occupation, the first two tenants moved into the Shanghai Tower last month, with more occupiers scheduled to move into the building during this quarter.