2025
Brighouse
Millers Oils Ltd
Vertical Access ltd
Maccaferri
Rockfall Protection and Stabilised Netting Solution at Millers Oils, Brighouse
Challenge
In early 2024, Maccaferri were contacted by Millers Oils after a series of dangerous rockfall incidents occurred at the rear of their factory in Brighouse, West Yorkshire. The industrial site is bordered by a steep 200m-long cliff rising up to 30m high, comprising heavily weathered sandstone and siltstone over mudstone with significant talus accumulation at the toe of the slope.
Several large rocks detached from the cliff and struck the factory building, damaging the curtain walling and creating major health and safety concerns for employees working adjacent to the slope. The repeated rockfall events highlighted the urgent need for a robust rockfall protection solution capable of stabilising the deteriorating rock face and safeguarding the operational facility.
During an initial site inspection carried out by Maccaferri in April 2024, extensive evidence of both historic and recent rockfall activity was identified immediately behind the factory. The rock slope presented an exceptionally high-risk environment, with unstable weathered rock formations visible across large sections of the cliff face.
A number of potential rockfall mitigation measures were considered, including rock scaling with draped rockfall netting, installation of a stabilised high tensile steel mesh system, and the construction of a high-energy rockfall barrier at the toe of the slope. However, each option presented significant technical and safety challenges.
Access to the cliff crest was extremely limited, while the close proximity of the factory building severely restricted working space at the toe of the slope. In addition, the heavily weathered nature of the sandstone created a substantial risk that drilling works required for rockfall barriers or rock anchors could trigger further instability and rockfall events, placing both installation personnel and factory workers at risk.
Solution
To develop a safe and effective rockfall stabilisation strategy, Maccaferri collaborated with specialist geotechnical contractor Vertical Access Ltd. A further inspection was undertaken in August 2024 by rockfall specialists from both organisations to assess the feasibility of the proposed systems.
Following this assessment, the rockfall barrier option was eliminated due to unacceptable safety risks associated with installing barrier posts beneath several visibly unstable boulders. Instead, the project team developed a hybrid rockfall protection system combining stabilised netting and draped netting technologies.
The northeastern section of the cliff, identified as the highest-risk area, was stabilised using Steelgrid HR30 high tensile steel mesh combined with rock anchors to form a permanent stabilised netting system. The southeastern section of the slope, assessed as lower risk, was protected using DT draped rockfall netting designed to safely manage smaller rockfall debris.
To enable installation works, Vertical Access Ltd utilised advanced roped access techniques to safely reach the crest of the slope. Extensive vegetation clearance and slope preparation works were undertaken to establish secure access and create a stable platform for anchor installation.
Detailed geotechnical design calculations and construction drawings for the rockfall netting systems were produced by Coffey Geotechnics. Maccaferri also carried out rockfall trajectory analysis to support the temporary works design and assess potential rockfall impact zones. This analysis informed the installation of temporary protective measures, including large hay bale barriers positioned behind the factory building to shield the structure during initial rock scaling operations.
Prior to installation of the permanent stabilised netting system, loose rock and unstable debris were carefully removed from the slope through controlled scaling operations. To further enhance safety during these works, temporary DT rockfall netting was installed to contain and guide falling debris safely to the base of the slope, protecting the rope access workforce and adjacent infrastructure.
During the summer of 2025, approximately 3,000m² of Steelgrid HR30 high tensile steel mesh was installed across the northeastern section of the cliff in combination with rock anchors and proprietary HR plates. A further 300m² of DT draped rockfall netting was installed to the southeastern section of the slope.
Steelgrid HR30 combines double twist steel wire mesh with integral high tensile wire ropes, delivering exceptional strength, flexibility and stiffness for challenging rock slope stabilisation projects. The system is particularly effective on irregular and heavily weathered rock faces where close profiling and high-performance stabilisation are essential.
Working in conjunction with rock anchors and HR plates, the Steelgrid HR30 system forms a robust stabilised netting solution that retains unstable rock blocks in situ, preventing future rockfall and significantly improving long-term slope stability.
The entire rockfall mitigation system was designed using Maccaferri’s MacRo Design software in accordance with Eurocode 7 and CIRIA C775 guidance, ensuring a fully engineered and compliant solution capable of protecting the Millers Oils facility for the long term.
This complex geotechnical project demonstrates the effectiveness of combining stabilised rockfall netting, draped mesh systems and specialist rope access techniques to deliver safe and practical rockfall protection solutions in constrained industrial environments.
Used Products
