Ongoing monitoring of Stoke Tunnel Cutting SSSI

Last November GeoSuffolk (the Suffolk Geology Group) was asked to monitor twelve Suffolk geological Sites of Special Scientific Interest for Natural England (NE). Of course we said yes.  Access to private, remote sites with some of the best geology in the county – what’s not to like?!  For the most part, this proved to be the case and armed with our lockdown letter of permission from NE, Bob and I spent many happy hours in several SSSIs in the Orford, Hollesley and Battisford areas. However, there was one tricky site in an urban area which involved land ownership problems, a busy railway line (which splits the site in two) and access to a school (during lockdown?). Stoke Tunnel Cutting SSSI in Ipswich has been designated to protect the interglacial lake bed deposits discovered when the tunnel was dug in the 1840s. These have been dated at approx. 210,000 years old and have yielded a variety of vertebrate fossils, some of which are on display in Ipswich Museum. Read Merv Russen’s article ‘Peter Bruff and the Mammoth’ in the January 2014 Newsletter for more information on these amazing animals.

Above: Stoke Tunnel Cutting SSSI from Luther Road – the grassy triangle in the centre is the Worsdell Close open space.

Our job was to visit the site and monitor the accessibility of its geology should future research need to be done. Network Rail was very accommodating and offered track visitor permits and even a tunnel visit – at night between 01:30 and 04:00! We settled for photographs of the cutting from the top of the tunnel entrance on Luther Road, also from the track access gates at the back of Worsdell Close, neither of which needed Network Rail personnel to accompany us. From Worsdell Close we had a good view of the part of the cutting investigated by Nina Layard in 1908. There is rarely any geology on view in tracked cuttings – Network Rail keeps them vegetated for stability – and that was the case here. However we were able to report no large trees (which damage the geology with their roots) or engineering works (no hard landscaping in this case).

Above: The Worsdell Close part of the SSSI showing the explanatory panel and with Hillside School the other side of the railway.

In addition to the cutting, two level areas, on either side of the railway line have been designated as ‘Finite Buried Interest’ sites. The interglacial lake bed is not large in extent and so areas have been set aside for study in the future. Who knows what 23rd century science will be able to achieve? The important thing for the condition survey is no trees or building works which disturb the geology beneath. The Worsdell Close locality was redeveloped from the 1919 railway siding area into a residential estate by Abbey Homes about 10 years ago and the SSSI has been maintained as a roughly triangular public open space. Funded by Section 106, GeoSuffolk erected a panel there in 2010 in order that the residents can understand why the SSSI is set apart as a level, grassed area (see July 2010 Newsletter). Our investigations have failed so far to establish whether Ipswich Borough Council, Network Rail, Abbey Homes or someone else is the owner. This area was easy to survey and is in good condition. However the panel has become faded and needs to be replaced, but it has been cleaned and the grass has clearly been mown a few times each year. The question is by whom?

On the other side of the track, the playing field of Hillside School is also part of the ‘FB’ SSSI. It looks fine from a distance, but so far lockdown has precluded us visiting it. Hopefully, vaccination and falling Covid-19 numbers will remedy this soon. As we reported to NE: there is light at the end of the tunnel.

Caroline Markham

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