Note: I had always hoped to contribute to the project, but unfortunately there was no response from the relevant CCCC/ECRL parties to whom I had emailed my CV and company profile.
About 3.8 km from where I live, at around 2.00 pm, a temporary steel canopy structure on the ECRL project collapsed. I happened to be in KL at the time, so I couldn’t visit the location, but after reviewing a video, several photos, and initial news reports, I managed to get a reasonable sense of what had occurred. Our chat group immediately lit up with amazement and theories. I had to smile when someone said, “It just fell by itself.” Even if it looked that way, every structural failure has root causes that must be examined.
Most importantly, I breathed a huge sigh of relief that no one was hurt or killed. It is almost a miracle that the woman driving the Suzuki Swift escaped completely unharmed.
1) My "Initial Assessment"
Based on the available video frames, the collapse appears to be a progressive structural failure, not a sudden, unexplained fall. The sequence clearly shows the canopy tilting from one side first, indicating an asymmetric loss of support, which typically marks the beginning of instability in temporary works.
Temporary structures such as steel canopies depend heavily on proper bracing, anchorage, sequencing, and balanced load distribution. Any deviation, whether due to dismantling, improper tightening of bolts, or uneven settlement, can immediately turn the structure unstable.
2) Key Observations
Initial Leaning: One support frame appears to have tilted first, suggesting possible failure at the base, bolt connections, or removal of key members,
Asymmetric Load Transfer: Once one side lost stability, the remaining members likely experienced overload, leading to a chain-reaction failure.
No External Impact: There is no sign of vehicle collision or crane contact, pointing toward internal structural or procedural issues.
High Sensitivity of Temporary Works: Factors such as ground settlement, inadequate lateral bracing, vibrations from passing vehicles, or premature component removal can all contribute to collapse.
Taken together, these early indicators point toward issues such as procedural non-compliance, premature dismantling, inadequate bracing, or support failure.
3. Possible Root-Cause Hypothesis (Based on Visual Evidence Only)
Immediate Cause (Most Likely) - loss of stability in one of the temporary support frames possibly from:
bolt loosening
base settlement
removal of a key structural member
failure of a brace or joint
4. Contributing Factors
Improper or unsafe dismantling sequence (this depends on whether the authority have approved the dismantling of temporary structures at the point of incident or otherwise) Fatigue or corrosion in bolts and connectors can also be the case, if the temporary structure overstayed its intended duration
Insufficient lateral bracing,
Vibrations from traffic below
Inadequate supervision or communication
Human error, such as removing the wrong component
5. Underlying Causes
Weakness in the temporary works design or review,
Missing or insufficient inspection procedures (torque checks, level checks, bracing checks),
Deviation from the approved method statement (AMS)
6. What It Likely Was NOT
Not caused by road users
Not due to a collision
Not a spontaneous collapse with no cause
7. Conclusion
The evidence points toward a preventable collapse resulting from instability in temporary supports combined with procedural or sequencing issues during dismantling.
8. Additional Technical Considerations
When I first reviewed the video, several failure possibilities became immediately noticeable:
Inadequate Lateral Bracing - Temporary structures depend heavily on lateral restraint. Missing or weak bracing can allow swaying or buckling even under minor forces,
Wind Load Underestimation,,
Temporary structures often overlook lateral or uplift forces from wind. Even a brief gust can destabilize a lightly braced canopy,
Base or Foundation Instability - Temporary supports often sit on pads or jacks. Soft soil, uneven settlement, or minor shifting can cause a tilt that progressively worsens,
8.1 Connection Failure
Bolts, welds, or connectors may fail due to:
fatigue,
improper tightening,
corrosion,
prolonged exposure beyond intended duration
Load Reversal / Unplanned Loads - If a crane lift or material shift occurred nearby, the structure may have been subjected to forces not accounted for in the temporary works design.
8.2 Sequential Collapse
Once one member fails, loads redistribute. Temporary structures with low redundancy often collapse rapidly once the first critical point gives way.
9. What Should Be Investigated Further
Authorities should look into:
Baseplates and jack supports for signs of settlement or lateral displacement,
Failed bolts and connections for metallurgical or fatigue analysis,
Presence, adequacy, and installation quality of lateral bracing,
Historical wind data at the moment of collapse,
Compliance with the temporary works design and approved dismantling sequence
Recent activity: Was any component removed earlier that day? Was there lifting or shifting nearby?
Even small displacements, if unrestrained, can lead to progressive collapse.
10. My Likely Scenario
A plausible explanation is:
The canopy lacked sufficient lateral bracing or had weakening components (fatigue, corrosion, or loose bolts),
A brace, joint, or connection failed-possibly suddenly, possibly gradually.
Load paths shifted, overstressing other members.
The base or frame on one side leaned, lost stability, and initiated a tipping or folding sequence.
Without adequate restraint or redundancy, the structure collapsed under its own weight or a minor lateral force.
This aligns with what we see in the video: a tilt, followed by progressive collapse.
11. Lessons and Recommendations
Always design temporary works for worst-case wind and lateral loads,
Use independent checks for bracing, connections, and anchorage,
Conduct regular inspections, especially for older or long-standing temporary structures,
Enforce strict sequencing during erection and dismantling.
Use tie-backs or guy wires for tall or slender temporary canopies.
Monitor and verify ground conditions, base supports, and torque on all key connections.
While I agree with DOSH’s preliminary findings, I believe the full investigation is still ongoing and rightly so. Their explanation identifies the trigger, but in structural engineering, the trigger is rarely the root cause.
A skylift boom striking a structure can indeed cause local failure if the structure is already vulnerable. However, a properly designed, adequately braced, and securely anchored temporary canopy should not collapse catastrophically from a single accidental knock.
This suggests the skylift impact was the initiating event, but the structure likely had pre-existing weaknesses, making it susceptible to sudden instability.
In other words, the skylift boom was almost certainly the final trigger not the sole cause.
It is important to wait for the complete forensic investigation, which should examine: bracing configuration, bolt tightness, condition, and possible fatigue, wind load history, vibration exposure from heavy traffic, dismantling or inspection sequence, adequacy of temporary works design, supervision and procedural compliance.
A safe temporary structure is expected to withstand a minor accidental impact. If it collapses instantly, it indicates that the system was already compromised.
Would this be right?
1) Wuhan Construction was carrying out paint-thickness inspection.
2) Workers were in the skylift cage, raised near the steel canopy.
3) During positioning or movement, the boom or basket made contact with the canopy.
4) If the canopy had weak bracing or loose joints, it failed upon impact.
The structure dropped onto the road below.
But again :
A properly designed temporary canopy should withstand minor accidental impact (this is industry norm).
So if a small collision caused total collapse, the deeper root causes may be:
- inadequate temporary works design
- missing or weak bracing
- poor joint tightening
- corrosion/weakening
- improper erection
- lack of supervision or approval for temporary works
The skylift may be the trigger, not the reason.
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