Case Study of a Quarry – Dry Rigg Quarry
Dry Rigg is a grit stone quarry located in Helwith Bridge, approximately 5 miles north of Settle in the Yorkshire Dales National Park. Gritstone is a sedimentary stone with exceptional wearing and skid-resistant properties.
Quarrying has occurred in this part of Ribblesdale for several centuries. Quarrying first began in 1780. Maps from the mid-19th century show 15 quarries working slate, sandstone and limestone. In the Victorian era, quarries expanded as they provided the raw materials for the growth of towns, factories and railways.
A number of quarries, including Dry Rigg, supplied handmade paving slabs for the streets and pavements of the rapidly expanding towns of northern England. Other uses of the rock were for stone cisterns storing soft water and even for brewers’ vats!
As road building developed so did the demand for stone that was both skid resistant and hard wearing. The rock from Dry Rigg was found to be ideal for surfacing highways. Quarrying has become more mechanised over the years.
Dry Rigg is one of only six English sources of this extremely hard wearing, uniquely skid resistant material.
Rock is extracted by controlled blasting, using between six and nine tonnes of explosives to produce over 20,000 tonnes of rock. Blasting is carried out about ten times a year.
The blasted stone is picked up by by heavy machinery and put into dumper trucks. These trucks carry the rock to the crushing plant where it is reduced in size in a three stage crushing process. It then passes through a screening plant that sorts the various sizes of stone from 20mm down to 3mm.
The finished product is then transported to construction projects all over the UK. Recent work includes the resurfacing of the Newbury bypass in Berkshire and ongoing maintenance of the M25 motorway around London.
Each year the quarry is visited by hundreds of school and university students from all over the UK. The site team have been working with the North Yorkshire Business and Education Partnership to improve links with local schools.
Many events and local organisations are also supported by Dry Rigg, including Horton- in-Ribblesdale Gala, Long Preston May Day festival, Settle Pool, Settle Golf Club and The Yorkshire Junior Championship Fell Races at Hellifield Gala.
The quarry directly employs around 80 local people on site and more people indirectly from the surrounding areas through road haulage and provision of services. Many employees live in the National Park and nearby area. The quarry has a turn over of around £3 million per year and the quarry contributes over £1 million a year into the local economy.
A range of measures have been taken to reduce the environmental impact of Dry Rigg quarry. These include:
Through careful work to create habitats that help wildlife, Dry Rigg has become home to many types of plants and animals. Over 25 species of bird breed on site, including Raven and locally threatened Lapwing. Over a hundred pairs of Sand Martins are also regular breeders. Scarce dragon flies and butterflies can be seen on the restored fen area, which also houses a healthy population of rare Great Crested Newts.
On the northern rim of the site is Swarth Moor, a raised peat bog which is designated a Site of Special Scientific Interest (SSSI). Tarmac takes an active role in monitoring the bog and is seeking to become involved in managing the site in partnership with Natural England.