Technical Analysis – Investigating the Alberton House Scaffolding Collapse in Manchester
A partial collapse at the Alberton House demolition site in Manchester city centre has triggered an investigation by Building Control and the Health and Safety Executive (HSE) after a large section of scaffolding gave way during works.
The incident occurred shortly before 3:00pm on Friday, 24 October, during active demolition works at the former 12-storey office building on St Mary’s Parsonage beside the River Irwell. No injuries were reported, but the event caused significant alarm in nearby offices, with witnesses describing a strong earthquake-like feeling as the structure gave way.
Background: Latent Structural Defect Discovered
Demolition specialist PP O’Connor, appointed by Bruntwood SciTech to clear the 1960s-built structure, later confirmed that a latent structural defect had been discovered in the building roughly a week prior to the collapse. The firm reported that the roof slab was not fully tied to the main frame, compromising the planned demolition sequence. After identifying the defect, the project team halted works, removed personnel and engaged independent structural engineers to review the risks and develop contingency measures.
According to PP O’Connor’s statement, the partial collapse followed this unforeseen failure, despite strict exclusion zones and safety controls being in place. Their contingency plans were successfully implemented at the time of the incident, ensuring no injuries and containing debris fully within the site footprint.
What the Photos Reveal: A Protection Scaffold, Not a Retention Frame
Following review of imagery published online, it is clear that the scaffolding system involved was not designed to retain or support any part of the building structure, as some early online comments have speculated.
Instead, the scaffold was a protection scaffold, installed to:
➜ Contain debris generated by mechanical munching equipment during the demolition sequence.
➜ Prevent falling material from reaching Bridge Street and the River Irwell below.
➜ Support debris netting and sheeting to reduce dust and vibration impact to neighbouring properties.
Protection scaffolds are common on city-centre demolition sites but are non-load-bearing systems; they should never be used to retain façades or structural walls.
What Likely Happened – Interplay Between Defect and Scaffold Instability
Preliminary assessment suggests that the latent defect within the roof structure may have altered the load paths and introduced unexpected dynamic effects on the adjacent scaffold. As the building was being progressively dismantled, sections of the protection scaffold appear to have been left beyond their supported zones, leaving them vulnerable to vibration and wind loading.
This type of instability is typical when a scaffold remains freestanding as the adjacent structure is weakened or removed. Images show bent ledger beams and displaced transoms, consistent with lateral tie failure followed by buckling, rather than a full structural overload.
Investigation Focus Areas
Inspectors from Manchester City Council Building Control and the HSE are now expected to examine:
➜ Whether temporary works coordination between the demolition and scaffolding teams was properly managed.
➜ The tie spacing and bracing layout of the scaffold relative to the building’s progressive removal.
➜ The effect of dynamic loads and vibration from mechanical munchers and local structural defects.
➜ Compliance with TG20:21 and BS 5975 regarding temporary works design and sign-off procedures.
The National Access and Scaffolding Confederation (NASC) has urged caution in assigning blame until a full report is complete, noting that scaffolding, when properly built and maintained, should not fail.
Acknowledging Intent and Advancing Safe Demolition Practice
While the incident at Alberton House drew significant public attention, it is important to recognise the engineering intent behind the measures in place. The protection scaffold was installed to safeguard the River Irwell, nearby roadways and adjoining occupied buildings, an example of good practice in urban demolition safety and environmental protection.
It is possible that the project team, acting in good faith and under agreed environmental controls, chose to retain the full scaffold height for as long as practicably safe to maintain protection against falling debris and dust emissions. However, as demolition advanced, an unanticipated and unconceived local failure appears to have occurred, transforming a controlled sequence into a sudden, unplanned event.
There is no indication of negligence or intent; rather, this was likely the result of complex and evolving load conditions that temporarily exceeded the scaffold’s designed capacity.
What matters most is that no injuries were sustained and all personnel and the public remained safe. The ongoing investigation by Building Control and the Health and Safety Executive will determine the exact technical cause and, importantly, provide lessons to strengthen future temporary works design and sequencing protocols.
Incidents such as this remind the industry that even with the best intentions and risk planning, temporary works demand constant re-evaluation as structures change. Each finding will contribute to a safer, more informed approach to demolition engineering in densely populated environments.
It is possible that the project team, acting in good faith and under agreed environmental controls, chose to retain the full scaffold height for as long as practicably safe to maintain protection against falling debris and dust emissions. However, as demolition advanced, an unanticipated and unconceived local failure appears to have occurred, transforming a controlled sequence into a sudden, unplanned event.
There is no indication of negligence or intent; rather, this was likely the result of complex and evolving load conditions that temporarily exceeded the scaffold’s designed capacity.
What matters most is that no injuries were sustained and all personnel and the public remained safe. The ongoing investigation by Building Control and the Health and Safety Executive will determine the exact technical cause and, importantly, provide lessons to strengthen future temporary works design and sequencing protocols.
Incidents such as this remind the industry that even with the best intentions and risk planning, temporary works demand constant re-evaluation as structures change. Each finding will contribute to a safer, more informed approach to demolition engineering in densely populated environments.
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| (Picture: MEN Media) |
