This article appeared in the September issue of Building Engineer journal:
Conserving the future of heritage tourism
Heritage led tourism contributes significantly to the UK economy and consequently, it is critical that the significance and value of our heritage is properly secured and safeguarded. Castles are popular tourist attractions across the country, with thousands of people coming to visit these spectacular historic monuments, and keeping these structures in good condition is vital to ensure they can continue to welcome visitors.
Leon Walsh, Senior Structural Engineer at Patrick Parsons and a heritage expert, discusses the engineering aspects of the restoration project that he has been giving expert advice on at Lindisfarne Castle, one of the most scenic visitor attractions in Northumberland.
Built in the mid-16th century using stone from the disused Lindisfarne Priory, the castle is more commonly known for the reimagining of the site in the 1900’s, carried out by architect Sir Edwin Lutyens for Edward Hudson, the founder of Country Life magazine.
The exposed location of the Grade I listed building overlooking the North Sea has seen it subjected to the ravages of wind, rain and salt throughout its 460-year history, and action needed to be taken to improve the building fabric and safeguard it for the future.
As part of the National Trust’s £3m restoration project, investigation works began in 2015. Patrick Parsons were appointed to provide structural engineering services for a series of trials to determine the most appropriate way of combatting the problems caused by the castle’s exposure to wet and windy weather.
The initial investigations helped to put together a full programme of works throughout the castle itself, which closed to the public in November 2016. The shop, garden, castle field, headland and lime kilns remain open to visitors.
Restoring this type of building, without causing irreparable damage is a challenge conservation expert Leon Walsh regularly faces.
Leon explained: “It is vital that any company working on historic buildings, whether contractors or consultants, have specialists who are sympathetic to the maintenance of the building fabric and have a sound knowledge of restoration practice to minimise intervention and permanent irreversible damage to the building.”
“The programme of works is critical to the long-term sustainability of the castle as a historic building and visitor attraction and it takes the correct expertise as well as the commitment from organisations such as the National Trust, to ensure that all the benefits of such an important historic site are recognised and conserved for future generations.”
Current works have included re-pointing and harling repairs to the walls which will provide protection from the harsh environment. The earlier repairs used a cementitious mortar which has damaged the stonework and led to water ingress into the building. Sympathetic repairs to the internal timber lintels has been specified to allow the existing members to appear as original, although in some cases, the inner portion of the lintel had completely disintegrated due to rot.
Leon continued: “Some interesting remedial works which were undertaken historically were exposed during the trials and included the use of an iron rail, possibly salvaged from the Holy Island wagonway, which was used as a relieving lintel over the stone window surrounds. Where degraded metalwork has been uncovered, it has been preserved and replaced with galvanised steel members.”
High level inspections of the castle walls and rock face are being undertaken to determine potential repair requirements to prevent loose stone falling from the crag. Hidden strong points have been installed at the head of the rock faces with approval of the ecologists to allow ongoing roped access inspections. The local ecology must be considered as the rock faces beneath the tower are a habitat for numerous birds and animals.
Patrick Parsons, who have a team of specialists with years of experience in historic buildings and conservation, have also provided civil engineering services. This has included a full and detailed drainage survey which, for the first time in the castle’s history, will record the location and condition of the drainage throughout the building as well as assessing the required capacity and discharge to the septic tank.
The programme of works has seen the castle emptied of its collection – the first time this has happened in over 100 years. The process of removing cementitious material from the internal and external walls has begun and Winter 2017 should see the internal finishes completed, while work progresses on the roof and gutter systems, ahead of the scheduled reopening in Spring 2018.