Photos | Extreme scaffolding on Lindisfarne castle restoration
An innovative scaffold structure has been erected around Lindisfarne Castle in Northumberland to facilitate restoration work on the 15th century building.
The tide, 90mph winds, and a lack of crane access on the volcanic extrusion in the North Sea were among the obstacles faced by contractors installing the scaffolding structure, which includes a temporary roof and will protect the castle from water ingress.
Subcontractor John Laidlaw & Sons, engaged by main contractor Datim Building Contractors, used a scaffolding system from Layher to come up with a solution to enable access to the castle, which dates back to the 1400s and sits at the end of a tidal causeway some three miles from the mainland.
Conservation works to stonework, windows and roofing to prevent further damage meant access was required to nearly every part of the castle's exterior.
The three-phase programme is scheduled to run over a period of 18 months. With a steep south-facing cliff-face against the North Sea with a further slope on its northern side, the variation in terrain had to be reflected by the scaffolding designs, Allan Laidlaw, managing director at John Laidlaw and Son explained.
“We were unable to tie-in into the cliff-face as this would have caused permanent damage to the rock so we used a combination of buttresses and kentledge,” he said.
“This allowed us to build a firm base to a height of 24m up to the walls of the castle itself upon which the access lifts could then be erected. On the opposite side, we pushed the scaffold further back from the walls to provide sufficient room for an installation that sloped gradually upwards towards the castle. Again, buttresses were used.”
The project also involved the use of a temporary roofing system from Layher. The Keder Classic roof, with a span of nearly 19 metres and a length of 40 metres, was designed in a rolling configuration in phase one and then fixed in position for the remaining two phases. Wind speeds could vary between 40mph between the ground and the temporary roof, 48m higher up. During winter, the high-level site weather station recorded winds in excess of 90mph.