St. Paul's Cathedral Dome Restoration

As part of a major internal conservation and refurbishment scheme, a solution was required to allow access for tradesmen to the full height of the cathedral dome.  The challenge was to ensure no more than a quarter of the dome was obscured at any one time, whilst the cathedral remained open to the general public.  Due to the sensitive nature of the internal finishes, no intrusive support fixings could be used.    

RDG Engineering designed a fully suspended access deck that covered 90 degrees, with the mobility to rotate a full 360 degrees.  The vertical loads were shared between a cruciform headframe positioned above the Golden Gallery, some 85 meters above floor level and a second cruciform positioned at the Whispering Gallery, 30 meters above floor level. Bespoke steerable bogies ran on steel plates seated on the Whispering Gallery, where the rotation of the scaffold took place.  Access for conservators was made possible every 2meters, enabling contact with all inner dome surfaces.  Due to the need to minimise self-weight, the entire structure was constructed with unique modular aluminium lattice beams and aluminium tube and fittings.  Over the duration of the contract, the scaffold segment completed 2 full rotations.