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| South Gare breakwater reinforcement 55,000 tonnes Norwegian granite installation, River Tees UK 2026 |
A 150-year-old structure. A storm that nearly broke it. And an engineering response that will define coastal infrastructure protection for decades to come.
On the Yorkshire coast of England, where the River Tees meets the North Sea, one of the most significant coastal engineering projects in the UK is now underway.
PD Ports has officially commenced a multi-million-pound programme to reinforce the South Gare breakwater a historic structure that has protected safe navigation into the River Tees for more than 150 years. The scale of the works is staggering: 55,000 tonnes of high-density granite rock, sourced from Norway, will be placed around the breakwater's base across two phases stretching into summer 2027.
For civil and coastal engineers, this project is a masterclass in resilience engineering and a case study in what happens when century-old infrastructure meets the accelerating reality of climate change.
What Is South Gare and Why Does It Matter?
South Gare is a man-made breakwater located at the mouth of the River Tees, near Redcar in the Northeast of England. Originally constructed over 150 years ago, it serves as the primary protective structure for Teesport one of the UK's largest and busiest ports and the wider river navigation channel.
Every day, thousands of vessels pass through the protection it provides. Millions of tonnes of cargo move through Teesport annually, supporting businesses, jobs, and investment across the entire Teesside region. Without South Gare, safe navigation into the river would be significantly compromised.
For over a century, this structure has silently done its job, withstanding the relentless force of North Sea storms. Until October 2023.
The Trigger: Storm Babet and the Wake-Up Call
In October 2023, Storm Babet struck the Yorkshire coast with devastating force. The breakwater at South Gare sustained significant damage a stark reminder of just how vulnerable even the most robust coastal infrastructure can be when exposed to increasingly extreme weather events.
Remedial repairs were completed in the months following the storm. But PD Ports recognised that reactive maintenance alone was no longer sufficient. With climate projections indicating that storms of similar or greater severity will become more frequent in coming decades, a long-term structural solution was needed.
That decision triggered 18 months of intensive engineering work.
18 Months of Research Before a Single Rock Was Placed
What makes this project particularly noteworthy is the depth of pre-construction investigation that preceded it.
PD Ports engineers, alongside specialist contractors, conducted comprehensive surveys of the breakwater including dive surveys and bathymetric mapping to fully understand the structure's construction, condition, and how wave energy impacts it across different storm scenarios.
The result was a reinforcement concept built around one core principle: place high-density rock around the breakwater's base to absorb and dissipate wave energy before it reaches the existing structure.
But before a single rock was placed in the North Sea, the design had to be proven.
Physical Modelling at HR Wallingford
The engineering team commissioned physical hydraulic modelling at HR Wallingford in Oxfordshire one of the world's leading centres for coastal and maritime engineering research.
A 1:50 scale model of the South Gare breakwater was constructed and subjected to simulated storm conditions equivalent to a one-in-200-year event among the most extreme scenarios engineers plan for in coastal infrastructure design.
The testing replicated the impact of a 9.2-metre high wave comparable in height to three double-decker buses stacked on top of each other. Only after the design demonstrated it could withstand conditions of this magnitude did the project move into the construction phase.
The Engineering Solution: What's Actually Being Built
The project is structured in two phases:
Phase 1 : September/October 2026 (Currently Underway)
- Approximately 15,000 tonnes of high-density Norwegian granite installed around the breakwater base
- Rocks measure up to 2.5 metres in diameter and weigh up to 30 tonnes each
- Placed predominantly below the waterline using a specialist installation barge
- Contractors: McLaughlin & Harvey, working alongside marine specialist Herbosch-Kiere
- Each rock is meticulously positioned to maximise wave energy absorption
Phase 2 : Summer 2027
- A further 40,000 tonnes of rock to be installed
- Completes the full armour layer around the base of the structure
- Total combined installation: 55,000 tonnes
The rocks are designed not to simply block wave energy, but to absorb and dissipate it a critical distinction in coastal engineering. By placing the armour layer predominantly below the waterline, the design intercepts wave energy at its source, reducing the load transferred to the existing structure above.
Why Norwegian Granite?
The specification of high-density Norwegian granite for this project is not arbitrary. Coastal armour rock must meet stringent requirements:
- High density - to resist displacement by wave action without requiring anchor systems
- Durability - to withstand continuous saltwater exposure and mechanical abrasion from wave impact
- Consistent quality - to ensure predictable structural behaviour across 55,000 tonnes of material
- Specific shape characteristics - individual rocks must interlock effectively to create a stable armour layer
Norwegian granite quarries are among the most consistent sources of high-quality, high-density coastal armour rock in Europe, which explains why the material is being shipped thousands of kilometres to the Yorkshire coast for this application.
The Bigger Picture: Why This Project Matters Beyond Teesside
The South Gare project is significant not just for the River Tees, but as an indicator of where coastal infrastructure engineering is heading globally.
Climate Change Is Rewriting the Design Brief
For generations, coastal structures were designed based on historical storm data. The assumption now widely challenged was that the past was a reliable guide to future conditions.
Storm Babet in 2023 was a direct consequence of the changing climate. As ocean temperatures rise and atmospheric energy increases, storm intensity and frequency are both increasing. Coastal infrastructure designed to 1970s or 1980s standards is increasingly being exposed as underspecified for the conditions it now faces.
The South Gare project responds to this directly. The one-in-200-year event standard used in the HR Wallingford testing reflects a much more conservative design philosophy than the one that governed the original construction. It is, in effect, future-proofing a historic structure for a climate that its original designers could not have anticipated.
The Cost of Doing Nothing
The economic case for this investment is straightforward. Teesport handles millions of tonnes of cargo annually. Any disruption to safe navigation whether from a damaged breakwater or a storm-related closure carries substantial economic consequences for businesses and supply chains across the region.
The multi-million-pound investment in South Gare reinforcement is, in economic terms, an insurance policy on an asset whose operational value is orders of magnitude larger than the cost of protecting it.
A Model for Ageing Coastal Infrastructure Worldwide
South Gare is not unique in its vulnerability. Coastal ports and harbours around the world were built in the 19th and early 20th centuries, using materials and to standards that reflect the engineering knowledge and climate assumptions of their era. Many are now facing the same reckoning that Storm Babet forced at South Gare.
The approach taken here comprehensive survey, physical modelling, phased rock armour installation offers a replicable framework for coastal infrastructure owners grappling with the same challenge elsewhere.
Key Engineering Facts at a Glance
| Parameter | Detail |
|---|---|
| Structure | South Gare breakwater, River Tees, UK |
| Structure age | 150+ years |
| Trigger event | Storm Babet, October 2023 |
| Project owner | PD Ports |
| Main contractors | McLaughlin & Harvey / Herbosch-Kiere |
| Phase 1 rock volume | ~15,000 tonnes (Sep/Oct 2026) |
| Phase 2 rock volume | ~40,000 tonnes (Summer 2027) |
| Total rock volume | 55,000 tonnes |
| Rock type | High-density Norwegian granite |
| Individual rock size | Up to 2.5m diameter / 30 tonnes |
| Design test standard | 1-in-200-year storm event |
| Wave height tested | 9.2 metres |
| Testing facility | HR Wallingford, Oxfordshire (1:50 scale model) |
| Placement method | Specialist installation barge, below waterline |
What Civil Engineers Can Learn From This Project
1. Invest in pre-construction investigation, The 18 months of surveys, modelling, and design work before construction began is not overhead, it's the difference between a solution that performs and one that fails. Physical modelling at HR Wallingford provided confidence that the design would work before a single tonne of rock was placed in the sea.
2. Design for future conditions, not past ones, The one-in-200-year event standard used here reflects a fundamental shift in how coastal engineers must think about design life. Historical storm data is no longer a sufficient basis for long-term coastal infrastructure decisions.
3. Below-waterline protection is often more effective, Placing the armour layer predominantly below the waterline, where wave energy is greatest and the existing structure is most vulnerable, is a more efficient use of material than above-waterline visible armour. Energy dissipation before impact is always preferable to resistance after impact.
4. Phased delivery manages risk Splitting 55,000 tonnes of rock installation into two phases allows the project team to observe Phase 1 performance through a winter storm season before committing to the final design and volume for Phase 2. This is disciplined, evidence-based engineering.
5. Coastal infrastructure is economic infrastructure The South Gare project is a reminder that coastal protection structures are not just engineering assets, they are enablers of entire regional economies. The investment calculus must include the economic cost of failure, not just the construction cost of protection.
Final Thoughts
As Paul Foreman, CEO of PD Ports, put it: "These are the largest works carried out on the breakwater since it was originally constructed more than 150 years ago. Our aim is not only to protect the structure today, but to ensure it continues to perform its vital role well into the future."
That sentence captures the essence of what resilience engineering is about in 2026. Not just fixing what is broken. Not just meeting today's standards. But anticipating tomorrow's conditions and building infrastructure that will still be performing its vital role when the next generation of engineers inherits it.
South Gare has protected the River Tees for 150 years. With 55,000 tonnes of Norwegian granite and the best physical modelling available, the goal is to protect it for 150 more.
Data and project details sourced from PD Ports official announcements, Teesside Live, Port Strategy, and New Civil Engineer (September 2026). All figures reflect the project specification as of the commencement of Phase 1 works.
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