Metal Fatigue On Under-Spec’d Suspension Wire Caused That LED Collapse At HK Concert: Task Force

August 31, 2022 by Dave Haynes

Metal fatigue on a suspension wire that was probably under-spec’d led to the collapse of an LED screen hanging over the performing stage at a boy band concert in Hong Kong in late July, according to a task force now looking into what happened and why.

The rated strength of the wire that snapped at a Mirror concert was 20 percent less than that of other wires available on the market, the task force reports in preliminary comments.

One of several panels suspended above the stage gave way during the performance, seriously injuring two dancers. One dancer has been discharged from hospital, but the other is still in critical condition and may end up with permanent paralysis. There are photos online I found while looking for an update, that show how and where he was hit. I recommend you don’t look at them. They’ll make you shudder.

The Standard, a Hong Kong publisher, reports:

The task force is led by Lee Tsz-chun, assistant director of the Leisure and Cultural Services Department. Lee, accompanied by Louis Szeto Ka-shing of the Hong Kong Institute of Engineers and expert advisor Eric Lim Chaw-hyon, spoke to the press on Wednesday after the group’s fourth meeting. 

Lim said they confirmed metal fatigue on the surface area of the snapped wire after magnifying the images by 5,000 times through an electronic microscope. 

Experiments also revealed that the strength of the snapped wire – with a diameter of 5 millimeters – was 20 percent less than that of other wires available on the market. 

Lim believed that the wire was damaged before it was installed on the set, and the “rope guard” used to secure the position of the wire put pressure on it and sped up the metal fatigue. 

He continued the fallen TV panel was way heavier than expected for the original stage design. 

Yet, when asked which party should be held accountable for the incident, Lee refused to comment and only said the investigation is still ongoing and expected to finish by next month. 

On the other hand, Szeto said they would investigate if there is any mistake when selecting materials or signing papers confirming safety. The Engineers Registration Board will hand down punishments when necessary, he added.