NEWSLETTER

Cullaloe Sandstone

The loss of the old Craigleith sandstone quarry, filled in and capped by the building of a supermarket, is, in microcosm, the problem faced by those charged with the responsibility of ensuring the appropriate repair and maintenance of Scotland's built heritage.

How can any conservation body, in this particular example - the Edinburgh World Heritage Trust (EWHT) covering as it does much of both the Edinburgh old and new towns, address this serious problem?

The "importation" of stone that appears to resemble that of Craigleith is one way of addressing the problem and on the 27th February, the EWHT held a conference entitled "Selecting the Right Building Stone" to address this and other related problems. The interest was so great it is understood that the conference was oversubscribed.

Amongst other prominent speakers Dr Ewan Hyslop, mineralogist and petrologist at the British Geological Survey, addressed "Stone Matching on Buildings" expressing the view that there were times when better decisions could be taken by those seeking to identify the most appropriate stone when repairs and maintenance is carried out on some of the built heritage.

He compared, in microscopic detail, samples of Craigleith sandstone (uniform fine sand) to those of other stones (generally medium to coarse sand, some containing clay minerals and generally not as porous) that are sometimes used as replacement stone in the EWHT area. Whilst decisions can be taken on colour - sand grain size, shape, content and porosity are but some of the other factors that should be considered when the most appropriate stone is being sought.

By the use of a PowerPoint presentation and microscopic slides, Dr Hyslop developed the debate with stone recently extracted from the Cullaloe quarry in Fife (see below) being seen as almost identical to that of Craigleith.

Cullaloe Sandstone test extraction

Further to the above, the SSLG played a part in the test extraction by introducing a stone company to the mineral rights holder with the matter then developing between the two to enable a test extraction be undertaken early in the year.

Block of Cullaloe Sandstone.

Samples of the freshly quarried Cullaloe sandstone were made available to the EWHT conference by Tradstocks Ltd which is now developing the possibility with the appropriate planning authority and it may well be, if all goes well, that new supplies of Cullaloe sandstone could be coming back on to the market once again in the not too distant future.

Ballachulish Slate

Readers will recall that the detailed exercise for the extraction of the test material from the Khartoum Quarry, Ballachulish, and its subsequent splitting into slate, was detailed in Newsletter No.4 and the samples secured forwarded to the University of Paisley for analysis.

At the time of writing this Newsletter the final report has not been delivered to the Community Council but it is hoped that there will be an opportunity to do this in the near future. Copies of the Report have been sent to the three funding bodies for their information.

It is sufficient to indicate at this time that the report details the structure and quality of the material (water absorption), the manner in which it split and its life expectancy.

The following article details how this issue will be progressed.

Hill of Foudland

Whilst the Ballachulish test exercise progressed, it was resolved that exploratory work on the Hills of Foudland (just south of Huntly) should also be progressed. With the permission of the land and mineral rights holder it has been agreed, due to the collapsed working faces, to extract some fresh slate block by a slightly less scientific method than that employed at Khartoum - namely some heavy equipment.

The slate secured will then be analysed by the University of Paisley and the final reports on both resources will be presented to Historic Scotland.

Carmyllie Flagstone

The Carmyllie sandstone quarries, in Angus, once operated at such a level that the output of paving and finely riven sandstone for roofing justified the building of a railway line from the quarries to Arbroath, some 5 miles, in order to enable sea transport of the finished product.

Whilst it is known that materials were sent as far a field as Germany, it is assumed that greater research will establish that significant amounts of either paving or roofing was transported by sea and used at locations up and down the east coast of Scotland.

Recycled Carmyllie Flagstone used as a roofing material
on steading buildings at Pitmuies House.

It is also a fact that, before the railways from the south brought in cheap Welsh slate, the Carmyllie finely riven roofing stone was the primary roofing material in this part of Scotland and a number of significant buildings are still roofed with Carmyllie sandstone "slates" - and, as with the demise of the Scottish slate production industry, this creates a major problem for those charged with the responsibility of ensuring the appropriate care and maintenance of Scotland's built heritage.

To address this material shortfall the SSLG has established contact with the planning department of the Angus Council and has also liaised with its Conservation Officer. In addition Alan McKinney, SSLG Chief Executive, has made contact with two farmers with mineral rights in the area who are interested in seeing the issue of this "material deficit" being addressed. Samples have been taken from these two quarries and consideration is now being given as to how best to proceed.

Restoring a steading roof at Pitmuies House
using recycled Carmyllie Flagstone.

An additional visit to the area was undertaken on the 16th May and the delegation was fortunate to observe restoration work being undertaken at Pitmuies House where the roofs of old steading buildings are being restored - new timbers when necessary and recycled Carmyllie flagstone roofing material. (see picture). For readers interested in this restoration work, it is possible to view the gardens (for a very modest contribution) and also see these impressive roofs. (Location - travelling on the road from Friockheim to Forfar the house is on the left approximately 2 miles).

A study tour comprising the Edinburgh Council, the Trust, Scottish Enterprise Edinburgh & Lothian, the Edinburgh City Centre Management Company and the consultants Ironside Farrer recently visited Manchester, Oldham and Huddersfield to consider natural paving stone sources. So the activities of the SSLG, in respect to seeking to identify an appropriate Scottish paving stone, is perhaps timeous.

But the old adage "What comes first - the chicken etc?" remains as the major hurdle. Without being able to define the potential market with any degree of certainty it is difficult to encourage potential investors consider the possibility of re-opening quarrying operations.

However that is the challenge!