It has taken nearly four years and cost about £800,000 to open the new Blisworth limestone quarry at Churchfield Farm near Peterborough but now the stone that has been used for centuries in some of the region’s important historical buildings is available from Churchfield Stone.

There has been a settlement at Lyveden in the countryside surrounding Peterborough on the border of Cambridgeshire and Northamptonshire since at least the Domesday Book, in which it is listed. So it was inevitable that plans to open a quarry in a field there would be preceded by an archaeological dig.

The dig has been carried out by Northamptonshire County Council’s archaeological services and has uncovered remnants of walls, ditches, domestic refuse pits and fragments of pottery, mostly from the 12th and 13th centuries. Further into the quarry there is evidence of late iron age and early Roman occupation.

Interesting though the archaeology is, Paul Robinson, a Director of Churchfield Stone, is glad it has finally come to an end and he can get on with extracting the Blisworth limestone from the new quarry.

The fact that he has gained planning permission and is able to do so, in spite of some local opposition, he attributes in no small measure to Professor Geoffrey Walton. “I think it was critical in obtaining planning permission that he was involved,” says Paul. “His direction and advice has been invaluable.”

And continues to be… because Professor Walton is now also helping Churchfield Stone in its planning application to open another Blisworth limestone quarry about two miles away with beds up to 800mm thick that will yield sizeable block.

Paul Robinson knows the value of Blisworth stone because he has been using it ever since he first started his building company, PGR Construction, in the area 25 years ago.

Blisworth stone has been used for centuries as a building stone, notably in churches and most famously for Sir Thomas Tresham’s Lyveden New Bield, now maintained as a ruin by the National Trust. New Bield is a mile or so from the newly opened Churchfield Quarry.

The stone has always been available, either from small scale quarrying or reclaimed, but generally it has only be possible to buy it in small quantities. The new quarry is near to a small former quarry, giving a hint to the availability of the stone, and will ensure that consistent supplies of the stone are available for restoration work, extensions and new build.

Suitable stone from the quarry will be taken to Churchfield Stone’s substantial works nearby for processing on the existing walling line – it exists because Churchfield already supplies a range of indigenous natural stone walling and dressed building stone, as well as indigenous stone flooring and fireplaces, sold through an exclusive range of outlets including Alma Small’s still expanding Mandarin chain.

As news of the new source of Blisworth stone has spread – not least as a result of it being displayed in local builders merchants but also because Churchfield Stone has held open days – the company has found it is being asked to price for an increasing number of projects, especially churches, from as far north as Sheffield and Derby.

As the stone is priced at £45-50/m2 against £90 typically being charged for reclaimed stone (when you can get it), it is anticipated demand will build up.

Blisworth from Churchfield is available in local branches of Howarth Builders Merchants, Jacksons, Buildbase and Travis Perkins and Paul Robinson hopes it will eventually be distributed more widely as news of it spreads and sales encourage the merchants to sell it in branches further afield.

“It’s an A-Star grade building stone,” says Paul. “We’ve had a lot of people getting in touch with us already – they want it!”

The Consultant's Contribution

Professor Geoffrey Walton & Associates LLP has been the consultancy involved in the investigations for the new Blisworth Limestone Quarry and its design for planning permission and operation. The quarry lies east of Churchfield Stone’s works on Churchfield Farm near Oundle. The comments below are based on Professor Walton’s report following his investigations.

PGW&A LLP was asked to investigate the potential building stone reserves in a 10ha field at Churchfield Farm, south-west of a previous stone quarry that had produced Blisworth limestone walling stone within the past few decades.

This limestone has been widely used across the county and especially in East Northamptonshire for listed buildings including the National Trust property at Lyveden, in conservation areas and in 18th and 19th century properties in many villages. Nevertheless, production of Blisworth limestone has been limited.

At Churchfield Farm, six cored boreholes were drilled and a trial pit was excavated to provide information for assessment and design. Drill cores from the six boreholes on the north-western side of the field showed up to 5m of overburden, including at least 3m of in situ Blisworth Clay. At full thickness, 3-3.5m of limestone was seen to be suitable as a source of building stone.

An additional 0.5-0.8m of blue hearted and finer grained limestone was also found to be present below, depending on the cover of Blisworth Clay. Where the Blisworth Clay cover is absent there is less blue hearted material at the base of the limestone and the Blisworth limestone is more weathered (this is quite consistent with many Jurassic limestones of building quality which commonly show improved characteristics when occurring beneath a clay cover).

The main, upper 3-3.5m of limestone (but less where the Blisworth Clay is absent) is the principal source of walling stone being present in units of 50-100mm and occasionally 200-250mm in thickness. This material is suitable for building stone (as coursed and random coursed walling) and walling stone. The thicker beds have been used previously for quoins and as ashlar strings, based on use in local buildings.

The lower 0.5-0.8m of limestone will be considered for the production of tiles. In the lower south-eastern sections of the potential working area this bed may be more grey than blue and therefore suitable for walling. The larger of these slabs appear to have been used for cills and lintels in earlier buildings. The volume of potentially recoverable limestone is computed as 93,600m³. This is equivalent to 210,000 tonnes of limestone, assuming a conservative unit density of 2.25t/m³, although some will be waste from quarrying and processing.

It is likely that the stone market will take two or three years to build up to a sales output of 5,000tonnes per annum. This will require a production of approximately 8,330tonnes of building stone with an additional output of limestone unsuitable for building stone of 16,660 tonnes. It is possible that the building stone output could increase above 5,000tpa, although experience suggests it is best to allow for the market to grow slowly.

Some or all of the unsuitable limestone may be sold as construction materials; such arrangements are not often encouraged by planners who see a risk in permitting building stone quarries in sometimes sensitive areas. In addition to persuading planners of the wisdom of selling excavated rock they often need convincing of the need to stockpile rock so as to provide sufficient working space.

The quarry was advised to be operated in a series of north-west / south-east cuts, advancing to the west. Each cut would be about 40m wide with advanced stripping of the next 40m cut and backfilling to restore the previous cut. It is essential to work thin layered building stone systematically and not leave some sections of stone for a later time “when the market is better”.