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Download - Hydrex Underwater Technology

Number 188Permanent on-site insert repair in South-Korea keeps ship out of drydock ............................... 3Underwater propeller blade straightening in the British Indian Ocean Territory. ..................... 5Underwater removal and reinstallation of bow thruster on container vessel. ............................. 7Underwater stern tube seal repairs in Algeciras and Le Havre ..................................................12


ContentsPage 3 - 4Permanent on-site insert repairin South-Korea keeps ship outof drydockPage 5 - 6Underwater propeller bladestraightening in the BritishIndian Ocean TerritoryPage 7 - 10Underwater removal andreinstallation of bow thrusteron container vesselPage 12 - 14Underwater stern tube sealrepairs in Algeciras andLe HavreKEEPING SHIPSIN BUSINESSISO 9001certifiedUnderwater services andtechnology approved by:©musicmanKEEPING SHIPSIN BUSINESSFully equipped for aworldwide fast response2


Permanent on-site insertrepair in South-Korea keepsship out of drydockIn May, Hydrex diver/technicianscarried out a permanentinsert repair on a 224-meter bulkerat anchor in Busan, SouthKorea.The vessel was being sold and therepair needed to be carried outbefore the sale could be finalized.The tight working window availablewas however no problem for theteam. Like all Hydrex divers theyare trained to perform a wide rangeof operations within the shortestpossible time frame and this withoutcompromising the high standardsHydrex is known for.A detailed underwater and on-boardinspection revealed a stress related120-mm crack in the ballast tankat the turn of the bilge. A 300 mm x350 mm plate was therefore constructed.The new insert was roundedto fit the exact shape of the hull.The team then cut away the partThe rounded plate from which the new insert was cut.of the bilge keel that was coveringthe damaged area. Next a cofferdamwas installed, allowing the diversto cut away an area around the crackin the ballast tank to the samedimension as the new insert. Afterpreparing the edges of the hole thenew plate was positioned and securedwith a full penetration weld.An independent ultrasonic testerthen carried out the necessary measurementsto make sure the weldingwas successful. The operation endedwith modification of the bilge keelto the specifications of the BV surveyorin attendance who then approvedthe entire repair.Hydrex diver/technician cutting away the area around the crack in the shellplating.During the operation the new ownersbriefly came on board to checkthe repair. When they learnedHydrex was the company hired by3


After the old plating had been cut away, the edges werepolished.The new insert plating was secured with screw docksprior to being welded.A full penetration weld finalized the installing of the newinsert.Ultrasonic tests were successfully carried out.the former owners to perform therepair, they left after only a quickinspection. Having worked withHydrex before, they knew the insertwould be carried out according tothe highest quality standards.The diver/technicians worked inshifts to make sure that the insertwould be installed before the deadline.This allowed the old and newowners of the vessel to finalize thesale on schedule.The new insert seen from the water side.4


Underwater propeller bladestraightening in the BritishIndian Ocean TerritoryWith all five blades of itspropeller severely bent, a290-meter container vessel neededa fast, on-site solution to restorethe propeller’s balance and efficiency.Hydrex diver/techniciansare trained to carry out repairsunderwater in the shortest possibletime frame and a team wastherefore mobilized to the ship’slocation in Diego Garcia in theBritish Indian Ocean Territory toperform a cold straightening ofthe blades.After the equipment arrived at thevessel’s location, the divers installeda monitoring station on a workboatand made all the required preparations.The workboat was then positionednext to the vessel and theteam leader went on board to discussthe details of the operation with theOne of the five bent blades of acontainer vessel propeller.Hydrex diver positioning the cold straightening machine over one of the blades.captain and the chief engineer ofthe ship and to go over the safetyprocedures.Next the team started the underwateroperation with a detailed underwatersurvey of the damaged propellerblades. Because fouling was presenton the blades, the divers carriedout a polishing to be able to inspectthe blades for stress fractures andcracks. The inspection revealed thatthe five blades had suffered multipledeformations along the trailing edgesand that there were stress fracturesand nicks in the same areas.Cracks were also found up to 15 mmdeep.Part of the team started the repairpart of the underwater operationwith grinding work on the blades toremove the cracks. Once this wasdone the locations were smoothed tocreate a hydrodynamic profile on thetrailing edges. Meanwhile, the restof the team also entered the waterand prepared the in-house developedhydraulic cold straightening machinefor the straightening operation.The divers carefully positionedthe machine over the bends of thetrailing edges of the first bladeand, in close communication withthe team leader on the work boat,applied pressure to return the bentblade to its original state. This procedurewas then successfully repeatedfor the other four blades.5


Hydrex/diver technician carrying out grinding work on the trailing edge of oneof the blades.Straightening the blades and polishingtheir trailing edges restored thepropeller’s optimum efficiency.When the divers had also completedall grinding and polishing repairson all identified cracks and gougesof the blades, they made a fullinspection of the newly modifiedcondition of the blades for theattending ABS surveyor and theHydrexcaptain of the vessel. With all partiesinvolved satisfied, the divers demobilizedtheir equipment and returnedhome.The operation restored the balanceand the efficiency of the propeller.By carrying out the straighteningon-site and underwater, Hydrexavoided a costly and time consumingdrydock visit for the ownerof the vessel.Permanent rudder repairs nowpossible without drydockinghas developed an entirelynew method enabling permanentrepairs of rudders withoutdrydocking the ship. Permanentrepairs were hitherto not possibleand ships had to drydock in case amajor defect was found. The newlydesigned equipment is lightweightand can be mobilized very rapidlyin our special flight containers.Therefore this new service is nowavailable worldwide.Major defects on rudders very oftencause unscheduled drydocking ofships. The new method designed byour technical department allows engineers,welders and inspectors to performtheir tasks in dry conditions.Class approved permanent repairson-site, without moving the ship,are now possible and commercialoperations can continue. Steel repairsand replacements can be performedand pintle and bushing defects can besolved without the loss of time andmoney associated with drydocking.The equipment can be mobilized withinhours to any port in the world and isavailable for rapid mobilization from theHydrex headquarters in Antwerp.6


Underwater removal andreinstallation of bow thrusteron container vesselDue to a malfunctioning bowthruster, a 334-meter containervessel had to use the services ofa tug boat for port maneuvering,so its owners requested Hydrexto take care of the removal,transportation and reinstallationof the unit. The operation wasperformed in stages on severallocations to allow the vessel tokeep to its sailing schedule.Together with all the necessaryequipment, the team travelled toRotterdam where the operationstarted with a thorough inspectionof the bow thruster unit. One byone the blades were then detachedand replaced with blind flangesto prevent oil from leaking fromthe thruster. Then the lifting andhoisting equipment that would beused to secure the unit during theBow thruster unit brought to the surface.Hydrex lightweight equipment ready for mobilization from fast response center.second stage of the operation wasinstalled. In the meantime, initialpreparations were made in the bowthruster engine room for the removalof the unit, so that there would beno ingress of water once the unithad been taken out.The vessel then left for Southamptonwhere it met up again withthe team which immediately continuedgetting the engine roomready. Next the support bracketsconnecting the gearbox to thethruster tunnel were cut and the unitwas secured with chains. It couldthen be fully disconnected from thethruster room and was carefullylowered, extracted from the tunneland brought to the surface. Thesecond part of the operation endedwith the installation of a blindflange to seal off the thruster tunnelfrom the engine room. The bowthruster unit was then transportedto the Hydrex fast response center7


COLDSTRAIGHTENINGOF SEVERELYBENT PROPELLERBLADESIn its quest to provide costeffective services to customers,Hydrex developed proceduresto address differentkinds of damage to propellers.This research led to the designof the Hydrex cold straighteningmachines first used in2002.Bow thruster unit on special cradle ready to be brought back into the thrustertunnel.by the team and sent on to Norwayfor repairs.By taking advantage of this techniquedamaged blades can bestraightened underwater, allowingthe ship to return to commercialoperations without the need todrydock. Blades can be broughtback close to their original form,restoring the propeller’s optimumefficiency.The cold straightening machineshave been in use for quite sometime now but the Hydrex researchdepartment has beenlooking into ways to expand thetechnique even further to improveour services. A newversion of the straighteningmachine was recently put intopractice. It is compatible withthe existing models and is usedto restore more severely bentpropeller blades to their originalcondition.As soon as the overhauled bowthruster gearbox was delivered tothe Hydrex headquarters, the diver/technician team and the unit weremobilized to the container vessel’snext port of call: Le Havre. After amonitoring station had been set upnext to the ship the team removedthe blind flange inside the thrustertunnel. The unit was then put ona cradle which was designed especiallyfor bow thruster operationsThruster unit and propeller bladesat Hydrex headquarters prior tooverhaul.Welding work on blind flange used to seal off thruster tunnel after removal ofthruster unit.8


into the thruster tunnel in one take.Hydrex monitoring station and overhauled bow thruster unit in Le Havre.Due to the size and weight of thebow thruster unit, special measureswere taken to lower the thruster unitand bring it inside the tunnel whereit was repositioned using chainblocks. Despite the extra difficultythis entailed, the team was able toreposition the gearbox with only aminimum of delay. The unit wasthen secured with bolts, but thechains were kept in place becausethere was no time left to reinstallthe brackets before the vessel hadto leave for the next port on its schedule.and which prevents the unit fromtipping. As it can be adjusted to thesize of the thruster, it allowed theHydrex divers to bring the unit backAfter fast stops in Dunkerque andHamburg the team met up with theHydrex has an office locatedin Clearwater in the TampaBay area that is ready to mobilizeimmediately. The office hasa fast response center that isequipped with an extensiverange of state of the art logistics,trucks, tools and diving supportequipment. This enables HydrexUS to efficiently service vesselsand offshore units calling onports in Canada, North, Centraland South America as well asthe Caribbean.Hydrex US ready tomobilize immediatelyAll staff members of the Hydrexoffice in Clearwater undergo stringenttraining at the Hydrex headquartersin Antwerp. They cancarry out both simple and complexhigh quality jobs even in the harshestof circumstances.Repairs to thrusters, propellers,rudders, stern tube seals, damagedor corroded hulls and all otherunderwater repair and maintenanceservices are done while the vesselis on-site. This eliminates the needto drydock.All used methods are fully approvedby all major classification societies.www.hydrex.usKEEPING SHIPSIN BUSINESSHydrex US604 Druid Rd,Clearwater, FL 33756Phone: +1 727 433 3900 (24/7)Fax: +1 727 433 3990info@hydrex.us9


The ship then sailed to Southampton.At this location the bracketswere secured, the pad eyes removedand the propeller blade boltssecured with wire. This concludedthe repair.Hydrex team members manoeuvring thruster unit.vessel in Rotterdam where the chainblocks were removed and the propellerblades were reinstalled one byone. Subsequently, the diver/techniciansreinstalled the support bracketsthat connected the bow thrusterunit to the thruster tunnel wall.The vessel can now maneuver insideports again without the needof a tugboat. Hydrex’s flexibilityallowed the company’s technicaldepartment to adapt the differentparts of the repair to the sailing schedule.The delay for the customer wasreduced to the absolute minimumand by performing both the removaland reinstallation of the bow thrusterunit underwater the vessel did nothave to go into drydock.Fast and high quality on-site repair services in theWestern Mediterranean area and North AfricaThe Hydrex office in Algecirasis ready to mobilizeimmediately with their two dedicateddive support vessels.Both vessels are fully equippedas service stations for a widerange of repair operations andallow for a fast response in thebay of Algeciras, Gibraltar andNorth African ports.As part of the Hydrex group,Hydrex Spain takes advantage ofthe companies’ 37 years of experience.All operations are carriedout by highly certified diver/technicians all of which have beentrained in the headquarters inAntwerp and have extensive experience,enabling the office tooffer their customers the high qualityHydrex is known for.Jobs recently carried out by HydrexSpain include a propeller modification,pipe repairs, rudder repairsand stern tube seal repairs inAlgeciras, propeller modificationsin Cadiz and an azimuth bowthruster removal and reinstallationon a pipe laying vessel inCartagena.Hydrex SpainPoligono Industrial Palmones IICalle Dragaminas Nave N2911370 Algeciras • SpainPhone: +34 956 675 049 (24/7)Fax: +34 956 921 914E-mail: info@hydrex.es10


Hydrex has certified divers at its disposal, readyto perform all types of offshore inspections.Underwater solutionsavoid drydockingFully trained and certified diver/techniciansRemoval of heavy marine foulingon FPSO and drill vesselsFast response centers withinstant mobilizable equipmentTurnkey underwater solutions for the offshore industryPhone: +32 3 213 5300 (24/7)Fax: +32 3 213 5321E-mail: hydrex@hydrex.bewww.hydrex.be11


Underwater stern tube seal repairsin Algeciras and Le HavreThe Hydrex flexible mobdocktechnique was used to performtwo underwater stern tubeseal repairs. Three seals werereplaced in Algeciras on a 250-meter roro vessel that was leakingoil, while the aft stern tube sealassembly of a 210-meter containership was partly repositioned in LeHavre to stop an oil blockage.Every Hydrex office has a fastresponse center equipped with allthe latest facilities, lightweightequipment and tools. These centersPreparation for bonding of new seals.were designed specifically to increasespeed of service and allowedus to mobilize diver/technicianteams to both vessels, from ouroffices in Algeciras Bay and our -headquarters in Antwerp respectively.After a thorough underwater inspection,the rope guard of the vessel inAlgeciras was removed. The splitring was then disconnected andbrought to the surface to be cleaned.Next the Hydrex flexible mobdockwas installed around the stern tubeseal assembly and a dry underwaterenvironment was created in whichthe diver/technicians could removethe damaged seals one by one andreplace them with new ones whichwere prepared onshore by the attendingAegir-Marine specialist.The Hydrex flexible mobdock repair technique is class accepted.After the rope guard was removedduring the operation in Le Havre thediver/technicians discovered that theoil flow through the stern tube sealassembly was blocked. This wascaused by the intermediate and sup-12


Hydrex diver/technician teams work around the clock if needed to carry out a repair as fast as possible.port rings both having been turned180 degrees the wrong way. Afterthe flexible mobdock was installed,the assembly was opened up and allparts were closely investigated andcleaned. This inspection revealedthat all seals were in good conditionbut that the bonding was in bad condition.The bonding of the seals wasconsequently repaired after whichthe seal assembly was refitted theproper way.Both operations ended with theconducting of pressure tests withpositive results, the removal of theflexible mobdock and the reinstallationof the rope guard.The roro vessel needed to crossthe ocean after its stop in Algeciras,but would not have been allowedentrance to any port in the UnitedStates due to the U.S. Coast Guard’svery strict policies concerning environmentalrisks. Thanks to Hydrex’sfast response, the captain couldcontinue on his schedule with theDuring a stern tube seal repair the rope guard and split ring are removed before the flexible mobdock is installed.13


oil leak repaired and with only aminimum of delay.The superintendent of the containership in Le Havre was also very satisfiedwith the service offered byHydrex. He said, “Even after thetypical late call on a Friday afternoonand even later that evening,Hydrex still managed to assembleand organize a team of divers thatarrived the next day in Le Havre.The job was completed well withinthe available time frame, includingfull re-welding of the rope guard andshifting of the vessel to anotherberth. In between, new divers andtechnicians arrived, all of whomseemed very professional and skilledin their work. We used Hydrexalso the week before on this shipfor another job in Dunkerque andthe response at that time was alsovery fast and professionally executed.”Dry working environment inside the Hydrex flexible mobdock.ON-SITE BOW THRUSTER OPERATIONSThe Hydrex lightweightflexible mobdocks are designedto be easily transportedaround the world and are usedto close off the thruster tunnelon both sides, allowing divers toperform repairs and other operationsin a dry environmentaround the bow thruster unit.This technique enables them toreinstall the propeller blades ofan overhauled thruster insidethe thruster tunnel after the unithas been secured or replace theblades or seals and perform repairwork on a specific part withoutremoving the unit.Since the development of thisflexible mobdock technique, numerousthruster repairs have beencarried out by Hydrex diver/techniciansaround the world.There is no need to send the vesselto drydock as all operations can becarried out in port or while thevessel is stationary at sea. Normalcommercial activities can thereforecontinue without disruption.Phone: + 32 3 213 5300 (24/7)Fax: + 32 3 213 5321hydrex@hydrex.bewww.hydrex.be14


Hydrex offers turnkey underwaterrepair solutions to shipownerswherever and wheneverthey are needed. Hydrex’s multidisciplinaryteam will help you findthe best solution for any problemencountered with your ship belowthe water line. We will immediatelymobilize our diver/technicians tocarry out necessary repair workwithout the need to drydock.Hydrex has a long track record ofFast underwater repairskeep ships out of drydockperforming complex permanent underwaterrepairs to thrusters, propellers,rudders, stern tube seals and damagedor corroded hulls. By creatingdrydock-like conditions around theaffected area, our diver/technicianscan carry out these operations in portor at anchor.All the projects we undertake areengineered and carried out in closecooperation with the customer andany third party suppliers, relievingthe customer of all the hassle of coordination,planning and supervision.Headquartered in the Belgian port ofAntwerp, we have offices in Tampa(U.S.A), Algeciras (Spain), Mumbaiand Visakhapatnam (India), and PortGentil (Gabon).All Hydrex offices have fully operationalfast response centers where anextensive range of state-of-the-artequipment is available at all times.Headquarters Hydrex N.V. - AntwerpPhone: + 32 3 213 5300 (24/7)E-mail: hydrex@hydrex.beHydrex Spain - AlgecirasPhone: + 34 (956) 675 049 (24/7)E-mail: info@hydrex.esHydrex LLC - Tampa, U.S.A.Phone: + 1 727 443 3900 (24/7)E-mail: info@hydrex.usHydrex West Africa – Port Gentil, GabonPhone: + 241 04 16 49 48 (24/7)E-mail: westafrica@hydrex.bewww.hydrex.beHydrex India - MumbaiPhone: + 91 222 2046 988 (24/7)E-mail: mumbai@hydrex.beHydrex India -VishakhapatnamPhone: + 91 891 2711 863 (24/7)E-mail: vishakhapatnam@hydrex.be

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