A174 Loftus Bank Slope Stability Assessment
Assessing a localised highway slope failure and identifying drainage-led remedial measures on the A174 coastal route.
- Slope Stability Assessment
- Geotechnical Engineering
- Drainage & Remedial Recommendations
Project Overview
Geotechnical assessment of slope movement at A174 Loftus Bank
Loftus Bank is a steep, wooded valley-side beside the A174 at Loftus. The road passes through East Cleveland and forms an important coastal connection towards Whitby, with the carriageway close to the slope crest and residential properties immediately beyond the affected area.
Redcar & Cleveland Borough Council commissioned Northpoint in 2019 following reports of further localised movement. Northpoint’s geotechnical engineers were appointed to assess the instability, identify the likely cause and recommend proportionate measures to protect the highway and nearby properties.
The commission formed part of a much longer history of slope instability. Northpoint’s review of previous records identified documented movement dating back to at least 1927, including a major slope failure in 1999 and further instability in 2004, followed by remedial works to protect the A174.
Client Requirements & Site Challenges
The renewed movement raised an important question for Redcar & Cleveland Borough Council: was this an isolated localised slip, or evidence that conditions at the slope crest were again influencing a historically unstable landform?
The affected area sat immediately below a live section of the A174, with residential properties close to the crest. Previous instability and remedial earthworks also formed an important part of the site history.
A further consideration was the absence of a formal kerb line and highway drainage system, which meant surface water could drain directly towards the upper slope.
Northpoint therefore needed to establish the likely mechanism of movement and provide proportionate recommendations that addressed both the immediate risk and the longer-term management of the slope.
Our Slope Stability Assessment Approach
Northpoint undertook a visual inspection of the affected slope and completed a Slope Stability Assessment, reviewing the localised movement in relation to the slope crest, the A174 highway, previous instability and the site’s drainage conditions.
The assessment identified uncontrolled surface-water ingress at the crest as the most likely trigger for the localised slip.
This finding focused the recommended response on controlling water reaching the slope, alongside proportionate remedial measures intended to stabilise the affected area.
Northpoint recommended the provision of a kerb line and highway drainage between the carriageway and slope crest to prevent surface water draining directly onto or into the slope.
The team also continued to support the Council with consideration of localised regrading and a planting solution intended to provide additional long-term support.
Key Findings
Northpoint’s assessment identified uncontrolled surface-water ingress at the slope crest as the most likely trigger for the localised movement.
The relationship between the highway edge, drainage conditions and historically unstable slope meant that controlling surface-water runoff was central to the recommended response.
The assessment also confirmed the importance of considering the latest movement within the wider historical context of Loftus Bank, where instability had previously affected the slope and required remedial intervention.
This allowed Northpoint to recommend a proportionate response focused on the specific mechanism identified rather than unnecessarily escalating the scope of remedial works.
Results & Deliverables
Northpoint’s Slope Stability Assessment provided Redcar & Cleveland Borough Council with a clear technical basis for responding to the localised failure.
The assessment translated the identified cause of movement into practical drainage and slope-management recommendations.
Immediate measures focused on protecting the A174 and nearby residential properties, including the provision of a kerb line and highway drainage between the carriageway and slope crest to prevent further uncontrolled runoff onto the slope.
Northpoint also continued to support the Council with consideration of localised regrading and a planting solution intended to provide additional long-term support.
The assessment gave the Council a proportionate framework for managing the immediate instability while informing the longer-term maintenance and monitoring of this historically unstable section of Loftus Bank.
Supporting Highway & Slope Stability Projects
Highway cuttings, embankments and natural slopes can be affected by a combination of ground conditions, drainage, historic movement and changes in the surrounding environment.
Northpoint provides Slope Stability Assessment, Slope Stability Analysis and geotechnical engineering advice to highway authorities, landowners and project teams managing existing or emerging instability.
Our engineers assess the relationship between ground conditions, drainage and observed movement to define practical, proportionate measures for investigation, stabilisation and long-term slope management.
Concerned about movement, drainage or instability beside a highway or development?
Northpoint can provide a proportionate Slope Stability Assessment to establish the likely causes of movement and recommend appropriate next steps for investigation, remediation or long-term management.