Monthly Archives: May 2014

Tunnel Thrusters- Repairs and Exchanges by the Handful!

SSA Flexible cofferdamAll 8 Subsea Global Solutions locations in Europe, the Americas and the Caribbean were busy repairing or replacing tunnel thrusters all around the world. Tunnel thruster removals took place in Europe (2), in the South Pacific Islands (1), on the West Coast of the USA (1) and in the Caribbean (1).  Two tunnel thrusters were installed in the Caribbean and several thruster repairs were performed in both wet and dry hyperbaric environments.

Tunnel thruster repairs were executed on several units on both commercial ships and cruise vessels.  7 tunnel thruster repairs took place over the past couple of weeks.  These repairs included a tunnel thruster shaft seal repair, blade seal replacements, CPP blade replacements, blade bolt replacements and weld repairs to permanently repair cracks and to install rope guards.

DCIM100GOPROTunnel thruster propeller blade, CPP blade seal and blade bolt replacements took place in a dry hyperbaric environment using SGS’ flexible dry door technology.  Properly spaced and rated attachment points were welded into place using Subsea Global Solutions class approved “A” class wet welding procedures. All wet welds were performed by certified welder / divers so that “rated” attachment points could be utilized.  With the fit for purpose and design rated flex door system installed the tunnel thruster tunnel was efficiently de-watered and repairs were completed efficiently.  No delays or changes to any vessel’s schedules took place during these repairs.

Wet tunnel thruster repairs were performed on several units to keep them operational and within the class acceptance criterion.  One tunnel thruster exhibited oil leakage from its bellows type shaft seal while in operation.  After consultation with the thruster manufacturer and seal supplier, a specialized adapter ring was engineered, fabricated and installed by Subsea Global Solutions.  With this fit for purpose ring installed the leakage stopped and the thruster could be put back into operation.  Allowing the vessel to remain coast guard compliant and in service is what makes Subsea Global Solutions’ the trusted resource for fleets around the globe.

Tunnel thrusters remain a critical and cost effective solution for large container and cruise vessels entering our congested harbors around the world.  Their proper operation is required and as such Subsea Global Solutions rises to the challenge of our clientele to keep them in service day in and day out.

Underwater Shaft Seal Renewal- Here There and Everywhere!


Subsea Global Solutions has been very busy providing support to our clientele in all locations around the world. In the past couple of weeks a shaft seal has been replaced on a cruise vessel while it was cruising on its Mediterranean itinerary.  Without taking the vessel out of service and with only minimal enhancements to the vessel’s itinerary the affected face seal as well as lip ring shaft seal system was exchanged in a dry hyperbaric environment underwater.

Subsea Global Solutions Europe performed the preparatory work on the vessel by removing the rope guard in a safe and efficient manner.  By using a carbon arc gouging system, the existing welds securing the rope guard to the vessel were gouged away and the rope guard was released from the vessel with no alteration.  Rigging pad eyes and specialized adapter rings were fabricated so that once the vessel arrived at its location for shaft seal exchange all was prepared and ready to go.

Subsea Global Solutions then mobilized additional trained and OEM certified diver / technicians from other Subsea Global Solutions locations located on East Coast of North America, West Coast of North America and the Caribbean.  As this was a very specialized seal with service being carried out by the OEM themselves, only OEM trained and certified personnel were allowed to perform this work.  Around the clock operations proceeded for 45 hours in order to exchange the specialized carbon faced seal ring, sealing seat and bond the necessary lip rings inside SGS’ specialized Flexible Hyperbaric cofferdam, the Transhab.  Since this sealing is so specialized and installation must be done in a controlled manner, Subsea Global Solutions certified their underwater exchange process together with their OEM partner last year through research and development performed both at the OEM’s production facility and at Subsea Global Solutions training and development center in Europe.

DSC01708With the shaft seal successfully exchanged within the required time frame, the vessel returned to its cruise through exotic Mediterranean locations assured that it’s shaft seal is guaranteed to provide years of good service.  Our commitment to excellence shines brighter and brighter as we continue to remain the industries gold standard for underwater service solutions.