Port Weller Dry Docks yard is one of Canada’s largest shipbuilding and repair facilities. Located near the entrance to the Welland Canal in St. Catharines, Ontario, the shipyard has special expertise in building self-unloaders and vessels such as the “Canadian Arctic” for service in Canadian northern waters. PWDD also carries out a large portion of repairs to the Great Lakes fleet. Since the mid-1970’s, Maple Reinders has provided Port Weller Dry Docks with single source responsibility for a total work programme, including: yard development, performance improvement studies, detailed design, procurements, construction management of various structures (offices, shops, warehouse, cranes), as well as a dry dock separation and retrofit/expansion. The dry dock separation involved construction of a new impervious 10 metre high by 220 metre long wall in an existing two level dry dock. This separation wall divided the original dry dock into parallel running shallow and deep docks. A new outlet structure and flap-gate were also incorporated, allowing independent operation of two dry docks. The installation of a vessel guidance system with special winches, bollards and transporter system was integrated with the wall design and construction, facilitating efficient vessel docking handling and maneuverability.