Mutford Lock repairs finish ahead of schedule

Recent repair works at Mutford Lock, one of the gateways to the Broads, saw it closed to vessels since 12 February 2025. The works progressed well and the lock has now re-opened to small vessels on 19 March, nine days ahead of schedule.

Mutford Lock is an historic piece of engineering and is approximately 200-years-old. Almost every part of the lock during this period has been repaired or replaced, with the gates last lifted out when they were replaced in the early 1990s.

One of the penstock sluices on the gate (which controls water flow) had failed and needed to be repaired by the Broads Authority and a team of specialist contractors including a crane company, a dive team, a repair team and electricians. A team of Canal and River Trust lock specialists provided their guidance and expertise to help assist the project.

The works were incredibly complex given the size and weight of the structures. Each gate is 6m long by 4m wide, weighing approximately 7 tonnes each. A dive team secured the lifting strops to the gate underwater and it was then lifted out entirely by a 150 tonne crane.

Divers then inspected the lock wall, an area normally inaccessible as it is covered by the wooden gates. A resistograph – a device that measures the resistance of wood to detect decay, cracks, and cavities – was then used to analyse the condition of the timber and assess which repairs were needed.

The gate was repaired, alongside any additional replacement of worn mechanical parts. Drone footage and photos show the final stages after the successfully repaired gate was lifted and secured back into its original location.

Broads Authority Waterways Projects Officer, Emily Leonard said of the works said: “Owing to its large size, the operation of Mutford Lock is complex when compared to other inland waterways locks, so this project required a team of highly-skilled experts to carry out the repairs.

“Thanks to the training by lock specialists from the Canal and River Trust, Broads Authority staff and our local contractors now have the expertise, confidence and knowledge to manage future repairs to this iconic structure.

“These repairs were to just one set of four pairs of gates at Mutford Lock, but we are now well prepared for ongoing inspection and carrying out any additional maintenance works in the future.”

Mutford Lock is the Broads’ second access to the North Sea, connecting Oulton Broad with Lake Lothing in Suffolk. The lock is typically used around 800 times each year for boats travelling between Oulton Broad and Lake Lothing.

The Lock was constructed in 1828 as part of new navigation routes for traders from the North Sea to Norwich. This included opening Lake Lothing to the North Sea to create a harbour and the construction of Mutford Lock to provide controlled navigational access onto Oulton Broad for boat traffic.

Due to different tides in Lake Lothing and Oulton Broad, the lock structure has an unusual bi-directional design. It has two pairs of opposing gates at each end to allow for high water levels on either side of the lock. The gates are a major control for the water level and flows on Oulton Broad and the separation of saline and fresh water. The Broads Authority manages the lock for the purpose of providing navigational access, not as a tidal barrier.

Mutford Lock is essentially a sea lock, with a different tidal cycle at each end, and the operation must be coordinated with the lifting of one or two bascule bridges to allow boats to pass through. To manage the operation safely and avoid potential major impacts on Oulton Broad the lock is operated by a team of trained lock keepers at East Suffolk Council and maintained by the Broads Authority and contractors.