RV Tangaroa dry docked for three-yearly maintenance
Our flagship research vessel RV Tangaroa recently spent 16 days in dry dock at Devonport Naval Base for three-yearly maintenance and repairs. A shopping list of tasks was done, including a fresh coat of antifoul, engine overhaul, new gen-set and corporate logo.
Because of RV Tangaroa’s large draught, Devonport is the only place in New Zealand it can dry dock. Costing $1.2 million, the process was managed by marine engineering specialists Babcock International.
RV Tangaroa is registered with Norwegian-headquartered classification society DNV GL, which sets safety, reliability and environmental standards for ships. Three-year dry docks are set down under that classification. Additionally, the hull coating and sacrificial aluminum anodes used to protect against corrosion are designed for a three-year life.
Dry docking a vessel the size of RV Tangaroa is a complex task, involving lots of pre-planning.
First, NIWA Vessels sends through a ‘docking plan’ that sets out hull appendages like gondola and azimuth. Wooden blocks are arranged in the dry dock to avoid sensitive pieces of scientific equipment and spread the vessel’s weight over the entire length of the hull.
The dry dock is then flooded to allow the ship to be floated in. It’s drained over the course of 4-5 hours. The vessel then comes to rest on a dry platform. The entire process is reversed to refloat the ship.