Engineering Design Consultants

Dalmuir Drop Lock

British Waterways Millennium Link Project involved re-opening the Forth and Clyde Canal that had been disused since the 1960's. The canal fell victim to the 1960's road culture and became blocked in several places. At Dalmuir, a bridge for a major road had been built within 300mm above the canal preventing vessels from navigating that stretch of waterway.

To overcome this, an entirely new kind of canal lock needed to be created that would effectively allow vessels to 'cross the road'. The innovative drop lock solution at Dalmuir was designed by David Price whilst working for Mandall Engineering Ltd.

The drop lock, was the first of its kind to be installed in this country, features a set of outward pointing mitre gates at each end of the lock. Vessels enter the lock and the water is pumped out of the lock until there is sufficient clearance between the water and the road bridge so the vessels can pass. Safety barriers are fitted to protect each set of mitres gates from the impact of a vessel, which could potentially cause the lock to flood rapidly, endangering the lock users.

A major hazard with a lock of this design is that if the lock was to flood whilst vessels are under the bridge, the vessel and occupants would be crushed. To prevent this, further safety barriers adjacent to each side of the road are fitted, which raise and lower with the changing water level in the lock. This prevents vessels from drifting underneath the road and potentially being crushed.

Involvement in the project included structural, mechanical and electrical concept design, detailed design, manufacturing drawings, project management of manufacture and site installation.

For more information regarding our waterways & flood defence design services or to discuss your lock gate requirements, please telephone 0114 399 0400 or email us.

Key Facts
  • Location:
    Clydebank, Scotland
  • Client:
    British Waterways