Tardebigge Top Lock, a striking Grade II listed structure on the Worcester and Birmingham Canal, faced an unexpected crisis in February. A sudden bulge, nicknamed the lock’s “belly,” appeared in its front wall, moving nearly 100 mm in just three days. The Canal and River Trust immediately closed the lock to protect boaters and the historic structure, marking the start of a complex rescue mission.
Emergency Engineering in Action
To prevent further collapse, engineers installed temporary king-span sheets to stabilise the lock. A detailed assessment revealed that the front 700 mm of the wall, the decorative façade, had failed, while the core structure and counter-forts remained sound.
This allowed for a precise restoration strategy:
- Carefully remove the damaged face
- Reinforce the existing wall
- Rebuild using original materials wherever possible
Two key techniques secured the structure:
- Sock Anchors – Stainless-steel bolts grouted into the wall expanded to fill hidden voids, binding the new façade to the original wall.
- Helical Stainless Ties – Created a modern cavity-wall effect, tying layers together for long-term stability.
Cawarden’s Role: Heritage Meets Sustainability
As a trusted name in heritage restoration and reclamation, Cawarden was instrumental in ensuring this project not only preserved history but did so sustainably.
The lock’s Grade II listed status and conservation area location meant traditional restoration methods were critical. Instead of simply replacing materials with modern alternatives, the project followed a “clean, reuse, replace” approach that Cawarden specialises in:
- Salvaging original Staffordshire blue bricks where possible
- Transporting damaged but reusable bricks to Cawarden’s Brick Reclamation Yard
- Cleaning each brick using dustless glass-bead blasting, which preserves the historic patina without harsh abrasion
- Recycling unsalvageable materials locally as aggregate or farm track base
This sustainable approach allowed the project to maintain authenticity while reducing cost and waste. Cleaning a brick costs around £1, versus £1.25 for a new one, a clear win for both the budget and the environment.
Watch: Martin Zero captures the brick cleaning process at Cawarden’s yard
Crafting the Perfect Replacement
For bricks that could not be salvaged, Cawarden helped source and supply near-perfect replacements. After testing five options, the team selected Kettley’s Staffordshire blue bricks, a close match to the originals.
- Made from clay sourced at Hollybank Quarry near Cannock Chase
- Fired slowly at ~1100 °C to achieve the lock’s iconic deep blue finish
These bricks ensure the restoration not only functions structurally but also preserves the lock’s 19th-century character for generations to come.
Watch: Court Above the Cut explores the cleaning and prep process in more detail
Engineering, Community and Craftsmanship
Built between 1815 and 1818, Tardebigge Lock replaced an early experimental boat lift and remains a testament to Britain’s canal heritage. Its design, combining buttresses (counter-forts), elm timber ties and blue brick belts, was carefully honoured throughout the restoration.
Thanks to the expert handling of materials by Cawarden, meticulous engineering and community support, a potential disaster has been transformed into a celebration of heritage craftsmanship.
The Canal and River Trust continues to invite the public to take part in the “buy-a-brick” campaign, allowing everyone to contribute to preserving this historic lock.
Through its commitment to sustainability and historic preservation, Cawarden has helped secure Tardebigge Lock’s future, ensuring that this iconic waterway can welcome the next generation of canal enthusiasts.
Watch: Richard from Cawarden explains the heritage materials and brickwork in the yard
Ready to start your own heritage restoration?
Contact Cawarden today to discuss your project and discover how our clean-reuse-replace approach can bring lasting beauty and integrity to your historic structure.