Seal System Retrofit for Cruise Ferry La Superba

seal system retrofit for cruise ferry La Superba

When the cruise ferry La Superba needed a La Superba is a cruise ferry, built by the Italian four-bladed propellers. This gives the vessel seal system retrofit, Wärtsilä was contracted shipbuilder Nuovi Cantieri Apuania for the ship a maximum speed of 30 knots. The electricity to do the job. The Wärtsilä Enviroguard owner Grandi Navi Veloci (GNV), part of the for the vessel is produced by four Wärtsilä Seal systems were installed after an in-situ Grimaldi group. It is one of the world’s largest Vasa 6R32 generators which generate a total machining of the shafts. and fastest luxury cruise ferries. La Superba output of 9,360 kW. – Wärtsilä’s solution meant that all work has a tonnage of 50,000. It measures could be done with the shafts remaining in 211.5 m in length and has a beam of 31.5 m. Shaft wear and seawater ingression place. This saved us both time and money, La Superba cruises the Mediterranean and The twin shafted vessel La Superba was fitted says the Grandi Navi Veloci representative. runs between Genoa and Sardinia. The main with lip seals and had suffered shaft wear engines are four Wärtsilä 16V46C units, which and seawater ingression. When consulted have a total output of 67,200 kW. The engines Wärtsilä’s seals experts recommended the drive two reduction gearboxes and a pair of use of water lubricated open stern tubes. Challenges Solution Beneﬁts

––Short dry docking ––Well planned and ––Well-known and tested seal period scheduled retrofit system – peace of mind for the customer ––Damaged shaft ––In-situ machining of shafts ––Further protection from “We did not hesitate surfaces due to ––Installation of Wärtsilä abrasion – less need for shaft retrofit wear and seawater Enviroguard Seal system ––Smooth operation of the seal to place an ingression (727 mm diameter) on port system – higher performance additional order for and starboard shafts ––Sealing solution better suited for the our sister vessel.” application – reliable ship operation

These are much better suited compared to a to abrasions in water lubricated type planning to manage all the tasks. We made it face seal arrangement, which is the standard applications. without delay and according to the customer’s solution for this type of system. request, states Rolando Marzapani. – Although lip type seals are an extremely Shafts restored prior to fitting the robust solution, they are more commonly used new seals Retrofit also for the sister vessel in oil lubricated systems, where the lip seals However, the work to replace the seals could The entire process from assessing the are lubricated with stern-tube oil, explains not start immediately. After the existing existing equipment, coming up with an Rolando Marzapani, Product Manager, equipment had been removed, the shaft agreeable, technologically advanced and Propulsion, Wärtsilä Services. surfaces needed to be restored to their proper cost effective solution, to quoting, supplying The technical benefits of the Wärtsilä state. Years of sea water ingression had and fitting the new seals was smooth and Face Seal were considered and evaluated damaged the surfaces to such an extent that trouble free. The customer was pleased with in open discussions with the customer and machining was required to bring them up to the transactions and services provided by confirmed after an onboard survey, leading to standards. This process took just under 7 days Wärtsilä. The customer was also satisfied with the retrofitting of the existing lip seals with the prior to the new seals being installed. Wärtsilä’s proposed solution as well as with Face Seal type Wärtsilä Enviroguard. – All this work was done with the shafts the installation services for the new upgraded The Face Seal option gave the vessel remaining in-situ. As the design of the new seals. higher performance and GNV a more cost face seals features a fully split system, this – The project execution was successful effective solution including peace of mind meant that work could be completed with and the vessel was taken into operation that no further damage would be caused to the shafts in place. This was a much quicker, without any problems and with excellent the shafts. It was not necessary to do any easier and more cost effective solution for us, performance, so we did not hesitate to place costly liner replacement or in-situ machining says the satisfied GNV representative. an additional order for our sister vessel, La caused by the previous sealing component Wärtsilä’s field service engineers Suprema, concludes the Grandi Navi Veloci wear, because the dynamic sealing interfaces completed the installation of the new shaft representative. are isolated from the shaft and hull. These seals. interfaces are designed and verified through – At the dry dock the customer also extensive in-service operation to demonstrate replaced other components. Therefore we extremely low wear and high resistance needed good communication and cooperation

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