Case Study Site 4 – Clavell Tower and Kimmeridge Bay, Dorset








Case Study Site 4 – Clavell Tower and Kimmeridge Bay, Dorset

1.         Location

The study site is located at Kimmeridge Bay, to the south of the village of Kimmeridge, within the East Devon-Dorset Jurassic Coast World Heritage Site. 

Figure 4.1: A view of Kimmeridge Bay in about 1920.

Image Courtesy: Private Collection. 

Figure 4.2: A view of Kimmeridge Bay today looking westwards along the coast.

Image Courtesy: isleofpurbeck.com

2.         Why was the Case Study Site selected?

The site includes two features of heritage interest.  First, the seventeenth century Clavell tower (MWX646), which was constructed in 1830/31 by the Reverend John Richards, and which is a listed building (National Heritage List for England 1120474).  The structure was at risk from coastal erosion and was relocated approximately 25m further inland in 2006.  Clavell Tower provides an interesting example of the impact of coastal erosion on heritage assets and illustrates the implementation of successful adaptation to coastal change (Stanford, 20083). 

Figure 4.3: Clavell Tower stands on the cliff edge above Kimmeridge Bay. 

Figure 4.4: A view of the Tower with flagpoles from c.1920s. 

The second feature is the remains of (the Scheduled) Kimmeridge Quay, together with jetties and breakwaters, which were associated with Sir William Clavell’s alum works on the shore (Cornwall County Council, 20141; Parkins, 20132).  The works operated between 1605 and 1618, after which the site was converted to salt extraction. 

3.         Summary of the Geology, Geomorphology & Coastal Processes

The Kimmeridge frontage is situated exclusively within the West Walton, Ampthill Clay and Kimmeridge Clay formations of the late Jurassic epoch; these comprise mudstones and muddy limestones.  The cliffs behind the Bay range in height between five and twenty metres but rising to sixty metres below Clavell Tower.  Erosion rates in Kimmeridge Bay average less than 0.5m per annum, although erosion has been at a lower rate below Clavell Tower (0.13mpa) on account of the durability of the strata of that particular location.  Sedimentary processes consist of a west to east transport system along the coast with inputs of material from the eroding cliffs at the back of the Bay (Figures 4.1 and 4.2). 

4.         Risks to Heritage Assets along the Case Study Frontage

Clavell Tower (listed Grade II) was constructed as an observatory and coastal landmark by the Reverend J. Richards in 1830/31 (Figure 4.3).  The frontage formed part of the Smedmore estate, which had been owned by the Clavell family since the 1420s.  At the end of the nineteenth century, until about 1914, the Tower served as a lookout post for coastguards and was vacated as the structure started to deteriorate (Figure 4.4).  Coastal erosion posed an increasing risk to the Tower and, in 2002, with the support and advice from the owner, the Landmark Trust commenced investigations into the possibility of relocating the tower further back from the coastline (Stanford, 20083). 

The coastal defence policy for the frontage was ‘no active intervention’ and, therefore, if the structure was to be preserved, an alternative solution was its relocation.  This represents a good example of practical management on an eroding coast in order to preserve the integrity of heritage assets such as the Clavell Tower.  Similar approaches to set-back of heritage features had been implemented successfully at Belle Toute Lighthouse at Beach Head in East Sussex in 1999 and at Compass Point at Bude in Cornwall.  Set-back was preferred to cliff stabilisation such as that undertaken at the Mussenden Temple near Castlerock, Northern Ireland, on aesthetic and environmental grounds as well as the cost involved.  The dismantling of the tower and its reconstruction approximately 25m landward of the cliff edge commenced in 2006, and the preservation of this landmark was concluded successfully, safeguarding the structure for the future (Figures 4.5-4.7). 

Figure 4.5: Clavell Tower prior to the commencement of its relocation twenty-five metres inland. 

Image Courtesy of The Landmark Trust.

Figure 4.6: Clavell Tower following its set-back.  The former site can be seen on the sea cliff. 

Image Courtesy of the Channel Coast Observatory, Southampton.

Figure 4.7: Clavell Tower following completion of the scheme by The Landmark Trust.

Image Courtesy of isleofpurbeck.com. 

A quay and associated jetties and breakwaters for the alum works and, later, the salt works, were located at Kimmeridge because of the readily available supply of fuel for the furnaces in the form of oil rich bituminous shales which were exposed in the cliff.  These industries flourished in the seventeenth century.  However, the venture did not prove successful financially, and the location did not lend itself to easy transportation of materials from the site, and these industries ceased (Cornwall County Council, 20141).  A small pier was constructed in 1858 to support extraction of bituminous shale for various uses, including fertilisers and oil production, but, again, this did not prove particularly successful.  The remains of the quay can be seen in the aerial photograph (Figure 4.8).  These features will be gradually lost as a result of sea level rise, erosion and undermining.   

Figure 4.8: The remains of the former Quay at Kimmeridge Bay can be seen in this aerial photograph. 

Image Courtesy of the Channel Coast Observatory, Southampton. 

5.         How can historical Imagery inform heritage risk management?

In this location artworks of the relatively undeveloped coast are limited, and it has not proved possible to find any detailed artworks showing the cliffline with Clavell Tower.  However, Clavell Tower appears in numerous photographs and so in this case study photography is the most helpful medium available. 

6.         Key Issues – What can be learnt from this site?

The site illustrates the impacts of coastal erosion on a heritage site located at the top of an eroding cliff and how the ‘set-back’ solution can be adopted successfully.  Here, the limitation on artworks means that photographic evidence is the only suitable medium to support understanding of long-term coastal change. 

7.         References

  1. Cornwall County Council, 2014.  ‘Rapid Coastal Zone Assessment Survey for South-West England’.  Report by Carolyn Royall.  Report Number: 6673.
  2. Parkins, J., 2013.  ‘The Kimmeridge Shale Industry, Dorset’. http://people.bath.ac.uk/exxbgs/journal_articles/01_Dorset.pdf.
  3. Stanford, C., 2008.  ‘Clavell Tower History Album’.  Report for the Landmark Trust.  Written and Researched by Caroline Stanford.