Public footpath, overhead powerlines and a partial dismantle
An intermediate scaffold sits over a busy city footpath, with a covered walkway at ground level and a 4.5 m clearance to a 11 kV overhead line running diagonally above one corner. The scaffold has been up for four months and is now to be partly dismantled so the facade below can be rendered, then re-erected. Pedestrian traffic is heavy at lunchtime. The site is fenced but the gate opens directly onto the footpath. The scaffold's tags show it was last inspected 12 days ago. A subcontractor wants to remove two bays of standards and ledgers to open a delivery access, then 'put them back Friday'.
1. Plan the preparation and sequence for the partial dismantle and re-erection, addressing pedestrians, the powerline and the access request.
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Before any work:
- Confirm the scope with a plan: which bays, in what order, what temporary support or ties are needed so the remaining scaffold stays stable. Removing two bays of standards and ledgers changes the load path and bracing - get written confirmation from the designer/competent person that the remainder is stable, or provide temporary ties and bracing.
- The 'remove and put back Friday' request should be refused as described unless designed. Opening a gap in a tied, braced scaffold is an alteration, not a convenience.
- Powerline: 4.5 m to an 11 kV line is inside the exclusion zone for plant and personnel unless the network operator has confirmed otherwise. Isolate or have the line de-energised/covered by the operator, or maintain the safe approach distance with a spotter and goalposts. Do not rely on 'it's only diagonal at the corner'.
- Pedestrians: keep the covered walkway and maintain a signed, lit, continuous route. Time the works to avoid lunchtime peak or provide a wider diverted path with marshals. The gate opening onto the footpath needs a banksman and a barrier so no one steps into the work zone.
- Inspection: 12 days is overdue for the stated regime - inspect and record before starting, and again after the alteration.
Sequence: brief and sign-on; isolate the powerline zone; erect edge protection and debris netting to the work face; add temporary ties/bracing; dismantle top-down in the planned bays, lowering components (no dropping); secure the open end with guard-rails and toe boards; inspect and tag; render; re-erect to the design and re-inspect before handover.
2. During the dismantle a coupler is found cracked and one tie is loose. What are the immediate actions and the follow-up?
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Immediate:
- Stop work in that area and keep people off the affected scaffold and the ground below.
- Barricade and tag the scaffold 'do not use - inspection required'. Do not just swap the coupler and carry on, because a cracked coupler and a loose tie together suggest either overload, movement, or a batch/condition problem.
- Make the loose tie safe only if it can be done safely from a protected position; otherwise leave it and get a competent person to assess.
- Check the powerline clearance has not changed if anything has moved.
Follow-up:
- Competent person inspects the whole scaffold: all couplers for cracks, thread damage and torque; all ties for tightness and fixing to structure; standards for plumb and settlement; bracing for disturbance.
- Quarantine and record the cracked coupler; check whether others from the same batch or supplier are affected, and check storage and handling.
- Replace defective components with rated, compatible parts; re-torque to specification and record values.
- Investigate why the tie loosened - vibration, wind, unauthorised removal, or fixing pull-out - and correct the cause, not just the symptom.
- Re-inspect and re-tag before work resumes; update the inspection register and brief the crew on the findings. If the cause is systemic, review the whole scaffold and the inspection regime.