Hydrex magazine 285 Magazine 285 · Hydrex founder Boud Van Rompay [email protected] Editorial Table of...

M a g a z i n e Number 285

Scrubber overboard pipe repairs in Rotterdam . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Underwater repair and maintenance solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8The real value of underwater inspections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Hydrex magazine 285_Magazine 285 24/09/20 08:55

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In-water bow thruster repairs

The Hydrex lightweight flexiblemobdocks are designed to be

easily transported around theworld and are used to close off thethruster tunnel on both sides,allowing divers to perform re-pairs and other operations in adry environment around the bowthruster unit.

This technique enables them to reinstall the propeller blades of anoverhauled thruster inside thethruster tunnel after the unit hasbeen secured or replace the bladesor seals and perform repair work ona specific part without removing theunit.

Since the development of this flexi-ble mobdock technique, numerous

thruster repairs have been carriedout by Hydrex diver/techniciansaround the world.

There is no need to send the vessel to drydock as all operationscan be carried out in port or whilethe vessel is stationary at sea.Normal commercial activities cantherefore continue without disrup-tion.

Phone: + 32 3 213 5300 (24/7)Fax: + 32 3 213 5321 [email protected]

www.hydrex.be


To receive a free copy, e-mail to:[email protected]

When we send a team to anoperation, any operation,

we have one goal in mind: to getthe job done in the shortest possi-ble time and to the highest stand-ards. This has been our policysince Hydrex was founded in 1974.Our track record proves this.

Over the years we have not onlybuilt long-lasting relationships withour customers, but also with classifi-cation societies and OEMs. Correctand direct communication is anessential factor in establishing and maintaining a network you canrely on. This allows us to quickly ar-range spare parts, an engineer from

the OEM or any external equipmentneeded for an operation.

On our website (www.hydrex.be)you can find a more comprehensiveoverview of the services we offer toour customers. If you need moreinformation on any these, do nothesitate to contact me. I am alwaysavailable to answer your questions.

Hydrex founderBoud Van [email protected]

Editorial Table of contents

ISO 9001 certifiedUnderwater services and technology approved by:

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Underwater repair and maintenance solutions 8-9

The real value of underwaterinspections 11-14

Scrubber overboard pipe repairs inRotterdam 4-7


Last month our diver/techni-cians carried out several

scrubber overboard pipe repairsin Rotterdam. On both a 140-meter roro vessel and a 200-metercontainer ship the corroded areasof the scrubber pipes were grind-ed out and rewelded. In both casesthe pipes were protected withEcospeed, a chemically resistantcoating produced by SubseaIndustries. The same protectionwas given to the three new pipesthat were installed on a 400-metercontainer ship.

Exhaust scrubbers are systems thatfilter out all harmful toxins fromexhaust gases of marine diesel en-gines. These can severely corrodethe pipes of the scrubber which canresult in water ingress if not handledquickly enough.

Scrubber pipe replacement

This was the case for one of thethree overboard pipes of the 400-meter container ship. The ownerasked us to replace the leaking pipeand to perform an inspection of theother two pipes. This revealed thatthey were also heavily corroded.

In communication with the owner itwas decided to replace these scrub-ber pipes during the same operationto prevent new leaks in the nearfuture.

Three cofferdams were constructedat our workshop based on the draw-ings sent by the customer. The teaminstalled these over the outlets of thepipes. This allowed them to perform

work inside the engine room withoutwater ingress.

Next the team cut away the oldpipes. The shell plating was thenprepared for the installation of thereplacement part. The new pipes hadalso been constructed at our ware-house in Antwerp with a diffuserand flange already in place. Thepipes were then positioned and se-cured with a full penetration weld.Next and independent inspector

carried out NDT testing of the weld-ing work.

To prevent the new pipe from cor-roding, the inside was coated withEcospeed. This product is producedby Hydrex sister company SubseaIndustries. Ecospeed is highly chem-ically resistant. Taking into accountthe nature of the process takingplace inside a scrubber, this is essen-tial for a lasting protection of thepipe. Ecospeed can also be used to

Scrubber overboard pipe repairs in Rotterdam

One of the corroded scrubber overboard pipes on container vessel.

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protect a newly installed scrubbersystem from day one.

Lasting corrosion protection

The corrosion on the scrubber over-board pipes of the other two shipswas less severe. It was situated onthe flange weld seams. A full re-placement of the pipes was not need-ed.

In both cases our diver/welders grind-ed away the affected area beforerebuilding it back to its originalthickness with clad welding.

When the welding was complete the surface was polished and a MPIwas carried out by an independentinspector.

The inside of the pipes was then coated with Ecospeed to keep themsafe from further corrosion.

Preparing the hole for installation of the new pipe.

Hydrex welder during installation of one of the new pipes.

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Scrubber pipe secured and ready for full penetrationweld.

One of our diver/welder during operation in Rotterdam.

NDT testing of the welding work on one of the pipes. To prevent the new pipes from corroding, the inside wascoated with Ecospeed.

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Conclusion

We offer a full package to ownersthat are experiencing similar dam-age. We replace the corroded ex-haust pipe while your vessel stays onschedule and we make sure that youwill not have to call us again in afew months’ time for the same prob-lem.

Most ships sail on a tight schedule.We know how important it is to prevent any loss of time. Our techni-cal department has many years ofexperience in drawing up a repairplan that fits in perfectly with a vessel’s schedule. Working in shiftsor splitting up an operation in stagesare just a few of the many ways wecan make sure that the impact of therepair is limited to the absolute mini-mum.

Contact us to find out how we canassist you. We are available 24/7.

+32 3 213 53 [email protected]

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Fully installed scrubber overboard pipe on container ship in Rotterdam.

Filling up the affected area withclad welding.

Scrubber overboard pipe ready tobe assembled again.

Corroded flange weld seam ofoverboard pipe on 200-meter ship. If you have received

this magazine at the wrongaddress or if your

company is going to move,please let us know.

You can contact us at:

[email protected] at

+ 32 3 213 53 00

KEEPING SHIPS IN BUSINESS


Underwater repSeal repairsWe have developed a reliable technology that enables the underwater replacementof all types and sizes of shaft seals.

Thruster repairsWe can assist shipowners with almost any proble

Rudder repairsWe can perform permanent repairs on any type ofat anchorage and cargo operations continue.

InspectionsWe offer a full range of hull monito-ring services including IWS and classinspections. This gives owners totalcontrol of their ship's hull condition.

Propeller buffingWe developed an efficient technol-ogy to enhance propeller blade surf-aces underwater and achieve surfaceconditions never seen before.

Anode installationWe can install both ICCP and sacrifi-cial anodes. If needed we can supplythe anodes.

TransOur teainstall withouschedu

Propeller repairsWhen damage to propellers occurs due to impact with ice and other debris we canfix these, even if the damage is extensive.

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Underwater maintenance


repair solutionsalmost any problem encountered with thrusters.

irs on any type of rudder while the vessel remainsns continue.

Hull repairsOur on-site hull repair services include the renewal of both small and large areasof damaged hull plating.

rifi-ply

Transducer installationOur teams can very quickly replace orinstall speedlogs and echosounderswithout any hindrance to a ship’sschedule.

BlankingWe can blank overboard valves, inlets,seachests or any other underwater opening to allow for onboard repairs.This is done very quickly and on-site.

Scrubber repairsWe can assist shipowners at moment’s notice when a scrubber pipe corrodes andneeds replacing.

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Phone: + 32 3 213 5300 (24/7)Fax: + 32 3 213 5321

[email protected]


Phone: + 32 3 213 5300 (24/7)Fax: + 32 3 213 5321

[email protected]

We discovered an unsophis-ticated but very efficient

technology to enhance propellerblade surfaces. With this methodwe can achieve surface conditionsthat were never seen before. Thiscan only be done underwater.

We have four workboats equippedto deliver this service on a veryshort notice in the Rhine-Scheldtdelta from Antwerp to Rotterdam.

propeller surfaces. Continuous andlarge fuel savings are now possi-ble.

This award-winning surface treat-ment technique justifies havingthe propeller cleaned every time itcalls a port.

Please contact us for more infor-mation, we will gladly discuss thebenefits of this new technologywith you.

When a comparison is made betweenthe surface condition of an averagepropeller, as our divers regularly seeit, and the smoothness that is obtainedwith our cleaning technique, savingsare in the 5-10% range. These resultsare easily achieved. The cost of suchan operation is very attractive and isvery easily gained back in a matter ofdays (or even hours).

Regular maintenance is easy toschedule and results in ultra-smooth

Large fuel savings with new propellersurface treatment technique

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• Ropes inside the stern tubeassembly which may cause sealproblems if neglected.

• Leaking stern tube or thrusterseals which can cause an environ-mental problem in port and leadto costly changes to a ship’s schedule if not caught quicklyand repaired.

• Clogged sea chest grids (prevent-ing proper cooling of the ship’sengines), or loose or damagedgrids.

• Loose or broken grids on thrustertunnels which can result in dam-age to thruster propellers.

• Damaged, bent, broken or de-tached bilge keels which againcan become much worse if notcaught early.

• A damaged rudder which willcontinue to deteriorate if notaddressed rapidly, resulting in theneed for much more costly repairsand representing a safety hazardin extreme cases.

Building upon conventionaltechnical skills and know-how

while also taking advantage of thelatest technology, Hydrex offers a unique hull monitoring service to its customers. This gives ship-owners total control of their ship'shull condition and consequently its performance, with only a mini-mum of work on their part.

Underwater inspections represent asmall investment and, if properlydone, have the potential to save anowner a great deal of money.

Competent underwater inspections,particularly if carried out regularlycan detect

• Problems with the propeller suchas bent or damaged blades (whichcan put undue strain on bearings),roughness due to fouling, cavita-tion damage or bad polishingwhich can reduce the propeller’sefficiency.

• Anodes which have wasted away,rendering the cathodic protectionsystem unworkable, leading tocorrosion and added hull friction.

• Hull cracks or other damagewhich, if not rapidly arrested, canworsen and increase the cost ofany subsequent repair.

Hydrex diver/technician during the inspection of a stern tube seal assembly.

Hydrex team arriving next to a ferry in Calais for a bow thruster inspectionwith a very short window.

The real value of underwater inspections

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Regular inspections carried out bycompetent divers and followed bycomprehensive and accurate reportscan detect any of these or other problems so that they can be cor-rected early and prevent the more costly repair which neglect and further damage would incur.

Because we have 45 years of expe-rience in both maintenance andrepair services, we can carry out anyrequired follow up repair very fastwithout any unnecessary loss oftime. Planning in a new slot is notneeded as all our diver/technicansare skilled to perform the repairwork as well.

If the damage found during aninspection can be anticipated, therequired equipment can be mobi-lized in advance. Otherwise it can betransported to the location of thevessel immediately from one of ourfast response centers where a largestock is available for our teams at alltimes.

This was demonstrated when a rope guard had come loose, whichwas revealed during an underwaterinspection. The Hydrex team secu-red the rope guard without any delayfor the owner.

Inspections before dry-docking

There is another important way forunderwater inspections to be used tosave costs. A thorough inspectioncarried out a week or two before aship is due to go to drydock can savea great deal of money in drydock.An accurate estimate of work re-quired can lead to efficient sched-uling. If thrusters are to be repairedin drydock they can be removedprior to the ship’s drydocking andcan be repaired and ready for rein-stallation when the ship is in dry-Hydrex divers are experienced in both maintenance and repair operations.

All three bow thrusters were inspected in the short time before the ferry had tosail again.

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dock, rather than waiting until thedocking to find out and then havingto extend time in drydock in order torepair and replace the thruster.

An accurate report on the state of therudder can lead to effective repairand recoating of the rudder so that itdoes not suffer further damage.

The all-too-frequent scenario of alow estimate for drydocking whichgrows exponentially once the dry-dock gate has closed and the ship isout of the water can thus be avoided.

Easy to combine with otheroperations

Because an underwater inspection is a small operation, it can be com-bined with one or more other oper-ations very easily. This can be another maintenance operation like a propeller buffing or any type ofrepair job.

By doing this, the shipowner is savedthe hassle and cost of multiple mo-bilizations and possible delays to hisvessel’s sailing schedule.

Speed is of the essence

Hydrex diver/technicians can carryout inspections underwater and on-site very swiftly without disturbingthe vessel’s sailing schedule. A goodexample of this are the inspectionsof the bow thrusters carried out ontwo ferries in Calais. Because of thenature of these vessels, the timeframe was extremely short. Bothtimes all three bow thrusters neededto be inspected in the small windowavailable. A change to the schedulewas out of the question as it woulddo great harm to the reputation ofthe owner.

Hydrex diver working on the rope guard.

We can carry out repairs for the shipping as well as the offshore industry.

If damage is found during an inspection, our team can perform the required follow up repair.

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We have always put great effort into minimizing the impact of ourservices to the schedule of a vessel.Our teams are trained to adapt themselves to the agenda of the shipand not the other way around.

Hydrex team leader monitoring an underwater operation.

An inspection will give a shipowner a perfect assessment of any damage, so that he can take an informed decision on whatto do.

In its quest to provide cost effec-tive services to customers,

Hydrex developed procedures toaddress different kinds of damageto propellers. This research led tothe design of the Hydrex coldstraightening machines first usedin 2002.

By taking advantage of this tech-nique damaged blades can be straight-ened underwater, allowing the ship to return to commercial operations without the need to drydock. Bladescan be brought back close to their o-riginal form, restoring the propeller’soptimum efficiency.

The cold straightening machines havebeen in use for quite some time nowbut the Hydrex research department

has been looking into ways to expandthe technique even further to improveour services. A new version of thestraightening machine was recently putinto practice. It is compatible with theexisting models and is used to restoremore severely bent propeller blades totheir original condition.

Fast underwater propeller blade straightening

Phone: +32 3 213 5300 (24/7)Fax: +32 3 213 5321E-mail: [email protected]

www.hydrex.be

KEEPING SHIPS IN BUSINESS


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Stern tube seal repairs

Using our flexible mobdockmethod to create a dry under-

water environment, we have car-ried out stern tube seal repairsand replacements underwater forsome years now in cooperationwith OEMs.

This technology brings drydock

conditions to the ship rather thanhaving to take the ship to drydock,saving a considerable amount oftime and money in doing so.

This class accepted method is performed by our diving teamsunder our warranty. It can be usedwhile the ship is carrying out its

usual cargo or other commercialoperations in port.

Visit the special stern tube sealrepair section on our website formore information and examples of the many seal repairs we haveperformed in recent years.

Phone: + 32 3 213 5300 (24/7)Fax: + 32 3 213 5321 [email protected]

www.hydrex.be


www.hydrex.be

Headquarters Hydrex N.V. - AntwerpPhone: + 32 3 213 5300 (24/7)E-mail: [email protected]

Hydrex Spain - AlgecirasPhone: + 34 956 675 049 (24/7)E-mail: [email protected]

Hydrex LLC - Tampa, U.S.A.Phone: + 1 727 443 3900 (24/7)E-mail: [email protected]

Hydrex RotterdamPhone: +31 10 313 25 19 (24/7)E-mail: [email protected]

We fix ships worldwide

This drawing was made in 1979and symbolizes our care and attention for ships.


Hydrex magazine 285 Magazine 285 · Hydrex founder Boud Van Rompay [email protected] Editorial Table of...

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Transcript of Hydrex magazine 285 Magazine 285 · Hydrex founder Boud Van Rompay [email protected] Editorial Table of...