Another Case For Sherlock Stones?

 

An illustrated talk to the Friends of Rotherham Archives

When writing this Language of Stone Blog, I have reported on my investigations of the geology, building stones and historic architecture of South Yorkshire and the surrounding counties - as well as other projects - in chronological order, with my last post recording an investigation of the geology and historic architecture of Halfway and Mosborough that was undertaken 13 months ago.

 

St. Helen's church in Treeton

Occasionally, projects that I am working on take considerably longer to conclude or evolve, as with the informal stone matching project at St. Helen’s church in Treeton that I started in February 2021, following the decision by Ulley Quarry to cease quarrying Rotherham Red sandstone for the foreseeable future – as reported in Another Stone Matching Exercise. 

 

The Brampton Chapel at St.Helen's church

 

Having had my various posts on Facebook noticed by Dorota Kowalik-Kociszewska – a very experienced Polish stone conservator who is currently working on St. Stephen’s Cathedral in Vienna – I was asked if I would be able to send samples of stone to her for petrographic analysis.

 

Cavernous decay in the masonry of the Brampton Chapel

Although I have examined very many different rocks using a polarising microscope, when a geology undergraduate - and in recent years to produce my Glowing Edges Designs Rock Art - I have never examined any building stones and I was more than happy to comply with her request; however, I couldn’t just knock a lump of a Grade I Listed Building with my Estwing hammer and waited a few weeks to see if any areas with cavernous decay on the Brampton Chapel failed after a heavy frost.

 

A sample of Rotheham Red sandstone above the plinth

Nothing had happened by April, but I found an area above the plinth, where a piece of stone just came away in my hand; however, being at low level and therefore potentially being in contact with water from the soil, Dorota thought that there might be a possibility of contamination with salts and asked if I could obtain another sample at a higher level.

 

A pilaster with cavernous decay on the Brampton Chapel

I managed to obtain another high level sample from the top of a pilaster a week later, when helping out with the day to day maintenance during the regular Coffee Morning, and sent both samples off to Poland, along with a piece of Rotherham Red sandstone from the drill core taken from my house when a new boiler was installed.

 

A sample from the top of the pilaster

During one of many days out in 2021, I noticed that recent repairs to the Chapel of Our Lady on the Bridge had been undertaken using Triassic St. Bees sandstone. Having previously seen it used for small repairs to the Old Town Hall back in 1995, when helping Mike Clark with his booklet - The Building Stones of Rotherham - I decided to obtain samples of this.

 

A new hood mould at the Chapel of Our Lady on the Bridge

Although I had asked the church warden for St. Helen’s church to put me in contact with the architect responsible for its repair, having seen the stonework deteriorate and made a thorough photographic record of its condition over the previous six years, this was never done.

 

Photomicrographs of Rotherham Red sandstone

When the photomicrographs of the various samples that I had sent to Poland finally arrived, along with detailed petrographic descriptions, I had by now realised that nobody involved with the maintenance of the church seemed to be interested in my observations or thoughts – including the salvage of any stone from the paving in the churchyard, which was now highlighted for repair by Rotherham MBC, for potential use in future ‘honest repairs’ to the fabric.

 

A summary of the petrographic analysis

 
Having just decided to carry on with my investigation of the Sheffield Board Schools, which I had made my project for the year, I was pleasantly surprised to get a message from the secretary of the Friends of Rotherham Archives, with a request to give a talk on my findings - having previously given a couple of talks to the group on similar subjects.

 

An article for the Dutch magazine Natuursteen

Back in 2003, the editor of the Dutch stone trade magazine Natuursteen introduced me as 'Sherlock Stones – The Geological Detective', when I wrote an article back in November 2003, describing the potential problems of ‘matching stones’ when restoring historic buildings – prompting me to refer to this in the title of my talk: Rotherham Red Sandstone Has Disappeared – Another Case for Sherlock Stones?

 

Devonian (L) and Triassic (R) sandstones when dry and wet

 
With Rotherham Red sandstone having been used for many other churches and historic buildings in many parts of Rotherham, I decided to use my experiences at St. Helen’s church and of devising the Triton Stone Library – now dismantled and awaiting to be displayed at Sheffield Hallam University – as the basis of my talk.

 

Rotherham Red sandstone churches from Hooton Roberts to Harthill

 
Over the years, since first undertaking a thorough investigation of the stonework at St. Helen’s church, I have visited all of the mediaeval churches in the Borough of Rotherham that are built in Rotherham Red sandstone and have noted the materials used for their repair.

 

Examples of Rotherham Red sandstone churches

 
These include the use of stone and brick tiles to undertake honest or conservative repairs, which were advocated by SPAB (Society for the Protection of Ancient Buildings) in response to the over-enthusiastic Victorian restoration schemes of the Gothic Revival.

 

A repair at St. Mary's church in Whiston

 
When giving my talk on 5th November 2022, I finished by highlighting the current pile of waste rock that has been excavated from the construction of new reservoirs at Boston Park in Rotherham. This contains a quantity of blocks of Rotherham Red sandstone that, although of no apparent interest to the major stone suppliers, are suitable for creating sculptural work in the park and for use in restoration projects – a resource that Green Spaces at Rotherham MBC will presumably retain for such uses.

 

Excavated Rotherham Red sandstone at Boston Park