One of the largest engineering programmes ever undertaken on Teesside’s iconic South Gare breakwater is now underway, as PD Ports begins a multi-million-pound project to strengthen the structure against increasingly severe storm conditions.

The works mark the culmination of 18 months of research, surveys, design development and modelling to identify the most effective long-term solution for protecting the breakwater at the mouth of the River Tees.

Constructed more than 150 years ago, the South Gare breakwater provides safe passage for thousands of vessels entering and leaving the River Tees each year and plays a critical role in protecting Teesport and the wider river infrastructure.

The structure was damaged during Storm Babet in 2023, highlighting the growing impact of increasingly extreme weather events on coastal infrastructure.

As Statutory Harbour Authority for the River Tees, PD Ports has committed significant investment to ensure the breakwater remains fit for purpose for decades to come, helping to protect vital operations along the river and maintain safe navigation for shipping serving businesses across the region.

The first phase of works will see around 15,000 tonnes of high-density granite, sourced from Norway, installed around the base of the breakwater using a specialist installation barge.

Contractors McLauglin & Harvey, working with Herbosch-Kiere will carefully position the individual 2.5m diameter rocks, weighing up to 30 tonnes each, predominantly below the waterline, where they will absorb and dissipate wave energy before it reaches the structure itself.

A second phase of works is planned for next summer when another 40,000 tonnes of rock will be installed.

Extensive testing has been carried out to develop the final design, including physical modelling at HR Wallingford in Oxfordshire, where a 1:50 scale model of the breakwater was subjected to simulated storm conditions seen in a one-in-200-year event.

That testing replicated the impact of a 9.2m high wave, equivalent to three double decker buses stacked on top of each other.

Paul Foreman, Chief Executive Officer of PD Ports, said: “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.

“South Gare is an essential piece of infrastructure for the River Tees and the wider economy of Teesside. Every day, it plays a critical role in protecting safe access to Teesport and the river for the thousands of vessels and millions of tonnes of cargo that support businesses, jobs and investment across our region.

“As Statutory Harbour Authority, we have a responsibility to ensure the long-term resilience of the river and the infrastructure that supports it. These works represent a significant investment in the future of Teesport, helping us maintain safe, reliable operations for our customers, river users and stakeholders for generations to come.”

Mark Pearson, Director of Project Engineering at PD Ports, said: “This project is the result of an extensive programme of surveys, research and engineering design work aimed at understanding how the breakwater performs under increasingly challenging sea conditions and identifying the most effective way to strengthen it.

“The rocks are being installed in a carefully engineered configuration that reduces the force of the waves before they reach the structure. By taking energy out of the water, we can significantly reduce the pressure on the breakwater itself and improve its resilience against future storm events.”

The works follow remedial repairs completed earlier this year to address damage caused by Storm Babet and form part of a long-term strategy to safeguard the breakwater against the effects of more frequent and intense storm activity.

The upgraded protection system has been designed with the overarching ambition of helping the South Gare breakwater continue protecting the River Tees for another 150 years.

Additional security fencing is in place on South Gare while these engineering works are carried out.