GCCM delivered by helicopter to allow installation for drainage improvements
Location of work/project:
Glenridding mine, Cumbria, England
Concrete Canvas Ltd.
Incredibly restrictive access on the Glenridding mine site meant some deliveries of the Concrete Canvas® GCCM had to be carried out using helicopters. Concrete Canvas® allowed for the complex project to go ahead, where traditional concretes and other alternative solutions were impractical or impossible to install.
The objective of this project was to re-line an existing 200m long channel on top of a tailings dam to prevent damage from runoff during severe rain storms. In recent years, such events had highlighted the need for adaptions and drainage improvements on the site.
Various methods had previously been used to line the channel, including dry stone walling and poured concrete. However, these were found to be insufficient as erosion control and water management measures during severe storm events. As a result, the Coal Authority, who provided advice to the client, Lake District National Park Authority, recommended Concrete Canvas® (CC) as the had successfully used the GCCM on several projects in the past.
CC was specified in both bulk and batched roll formats; the deliveries were transported up a remote track on the hillside on a HIAB wagon to an off-loading point 500m away from the site and then flown into position by commercial helicopter.
The bulk rolls were cut to required lengths and laid longitudinally in narrower sections of the channel where the profile was less varied. Where the channel was wider than 1.1m in total, or bends or larger variations in profile had to be accommodated, the batched rolls were used and installed transversely. The pre-batched and site-batched rolls were easily transported manually by the installation crew and eliminated material waste.
CC’s main advantages over conventional concrete are speed and ease of install, cost savings, durability and environmental friendliness. Concrete Canvas® GCCM has a low alkaline reserve and low washout rate, meaning it can be installed on environmentally sensitive sites without need for treatment of runoff before it’s discharged, and without risk of adverse effect on the local ecology. This was especially important as the site is now a designated Scheduled Monument, while the area above the tailings dam is designated as a Site of Special Scientific Interest (SSSI) for rare plant species.
A total of 965m² of the 8mm and 13mm thick variants of CC (CC8™ and CC13™) were installed over ten days by the 7 5 Engineer Regiment under 4 2 Brigade for the Lake District National Park Authority, with support and design input from the UK’s Coal Authority and Environment Agency.