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Cave conservation

The following articles and videos discuss various aspects of the Cave's deterioration and the task of conserving its carvings for future generations.

Historial Cave's Endangered Insect Infestation

The Guardian, April 2010

Royston Cave: an holistic approach to conservation

Journal of Architectural Conservation, December 2014

Race to save rare cave carvings

BBC Look East, June 2009

Chalk eating worms move on

Cambridge News, August 2014

Tobit Curteis, wall paintings conservator and specialist in environmental control at historic sites, outlines his recent work at Royston Cave

Excerpt from Cornerstone magazine, Issue 1, 2010

Over the course of the past 50 years numerous attempts have been made to understand the deterioration and to repair the damaged carvings. However, most studies have ended prematurely and only limited remedial measures have been implemented. In 2008, a detailed study of the Cave was commissioned by the Royston Town Council and supported by a generous grant and specialist advice from English Heritage, with the aim of understanding how and why the Cave is deteriorating, so that measures to conserve it could be developed.

It immediately became apparent that the causes of deterioration are as unusual as the Cave itself. Because it is carved in soft, Upper Cretaceous chalk, (rather than the harder, older beds) very little research has been done on the precise decay mechanisms or their control. To add to this, there is relatively little research in the UK on the deterioration of this type of cave structure. Therefore, the project, which will take a number of years to complete, involves basic materials research, as well as the latest digital survey techniques more commonly associated with historic building conservation.

The preliminary results have demonstrated that the primary cause of deterioration appears to be minor dimensional change of the chalk, as a result of fluctuations in the moisture content, resulting largely from periodic flooding, but also due to changes in the microclimate. This leads to internal stresses which cause fine cracks to occur, often in the vertical plane between the raised carved detail and the main face of the Cave. The fissures are then colonised by microbiological growth and animals, causing the cracks to enlarge and eventually these sections of carving to fall away. Historically, this may have been exacerbated by traffic vibration, although since the opening of the nearby bypass in the 1980s, this is likely to have been substantially reduced.

In conjunction, damage has been caused to the chalk by worms, which appear to feed on nutrients which have entered as a result of flooding with foul water. The effect of the worm activity is to cause a loss of cohesion and collapse of certain sections of a softer chalk and a consequent loss of the carved detail.

With the basic decay mechanisms now apparent, both preventive and interventitive conservation approaches are being evaluated. As with all sensitive historic structures, the primary aim is to control the deterioration mechanisms and, therefore, minimise the level of treatment that needs to be applied. Given the unusual nature of the structure and the limited reversibility of treatments, an extremely cautious approach is being adopted, and the conservation process will be slow and painstaking. Indeed, the real conservation process will be open ended as, once the current phase of damage is stabilised, the long term survival of the Cave depends on preventing future deterioration, rather than treating it once it has occurred.