New propulsion seals for Port Nelson's tug, 'Toia'
CoVid travel restrictions which meant the NZ border was closed to Kongsberg engineers from Australia resulted in some scheduled work having to be completed after the five-year survey on the Port Nelson tug ‘TOIA’ was completed in December 2021. TOIA was back on the Port Nelson slipway for repairs to seals in the propulsion systems in February 2022. A Nelson-based Kongsberg staff member was available to confirm warranty procedures on site as Diverse completed the job.
Oil leaks were discovered in the turning gear which needed prompt attention; the units carry approximately 1500 litres of oil on each side. The entire Azmi L-drive propulsion units, weighing 12 tons, were dropped down and it was determined that their sets of internal lip seals were slightly damaged, causing the leakage. These were replaced within each drive unit together with a new 600mm diameter steel liner before raising the propulsion unit back up and tightening each unit’s 20 hex bolts to 2,700 ft-lb of torque, using a hydraulic wrench.