Safety responsibilities and duty holders
Safety responsibilities and duty holders is the domain that tests who must do what when a truss-out scaffold is planned, erected, used and removed.
Contractor and subcontractor
The principal contractor controls the site and must provide a safe system of work, a suitable design, competent supervision, safe access, PPE, training, emergency arrangements and public protection. A subcontractor who erects the scaffold has its own duty to plan the work, provide competent workers, inspect the scaffold and coordinate with other trades. Delegating the task does not delegate the duty.
Competent person
The competent person is appointed by the contractor, has the training, experience and knowledge to inspect the particular scaffold, and must be independent enough to stop work. The competent person checks anchors, ties, bracing, couplers, boards, guardrails, toe boards and mesh, and records the result. Design changes go to the designer or qualified engineer, not to the competent person by default.
The scaffolder's own duties
A registered scaffolder must work to the agreed design and sequence, use the supplied PPE, keep the platform clear, avoid improvising with incompatible parts, report defects and refuse an unsafe instruction. The scaffolder must also protect residents and the public below by fixing toe boards, mesh and exclusion zones.
Worked example
A subcontractor tells a scaffolder to add an extra bracket to support an air-conditioner because the resident complains. The correct response is to stop: the extra load and eccentricity change the design. The scaffolder reports it to the competent person and contractor; the designer confirms whether the bracket and anchors are adequate; only then is the work done and inspected. Doing it 'to help' transfers risk to everyone.
Traps
Do not assume the competent person can redesign any scaffold. Do not assume the contractor's safety officer supervises erection. Do not accept verbal instructions that bypass inspection, and do not let other trades hang loads or alter ties.