Number 172

Increasing number of underwater rudder repairs reveals need for a lasting protection against cavitation and corrosion damage:the Ecospeed solution

Hydrex and AEGIR-Marine:performing underwaterstern tube seals and propeller operations acrossthe globe

Hydrex aroundthe world

The value of regular under-water propellerpolishing

Hydrex WhitePaper #3

The new quarterlyJournal of ShipHull Performance

An interview withDave Bleyenberg,Hydrex ProductionExecutive

2

Throughout the yearsHydrex has invested in

the development of under-water hull cleaning equipmentand now offers an internatio-nal service that can give shipsback their efficiency. Thisquick and effective service isoffered on a worldwide basisthrough a network of under-water hull cleaning stationsstrategically located aroundthe planet.

All Hydrex underwater hull

cleaning units are carefully

constructed to minimize the

occurrence of damage on the

underlying paint layers while

still removing all types of

fouling. This restores a vessel’s

performance as close to its

optimum condition as possible

and offers ship owners a con-

siderably saving in fuel.

All Hydrex offices and service

stations are equipped with

multiple sets of these hull

cleaning units which can be

mobilized rapidly to any port.

All divers are trained to

achieve the fastest possible

cleaning rates without losing

the high quality Hydrex is

known for.

EASY AND EFFECTIVE UNDERWATER HULL CLEANING

AROUND THE WORLD

3

Increasing number of underwater rudderrepairs reveals need for a lasting protectionagainst cavitation and corrosion damage: the Ecospeed solution 5 - 8

Hydrex and AEGIR-Marine: performing underwater stern tube seals and propelleroperations across the globe 9 - 14

Hydrex around the world 16 - 21

The value of regular underwater propellerpolishing 22 - 23

Hydrex White Paper #3 25 - 26

The new quarterly Journal of Ship HullPerformance 27

An interview with Dave Bleyenberg, HydrexProduction Executive 28 - 30

Table of contents

way the Ecospeed Ship Hull CoatingTechnology can help ship owners prevent it from (re)occurring.

This article is followed by a secondfeature article in which we spotlightHydrex’s stern tube seal repairs andour work with AEGIR-Marine. Thiscooperation is beneficial for Hydrex,AEGIR and the customers of both companies. We can offer stern tubeseals operations on all types of sealsas well as a full range of propellerservices, all of which can be carriedout in dock, on a trimmed vessel or underwater by Hydrex-diver tech-nicians.

Also in this magazine: a short sum-mary of some of the operations thatwere recently performed around theworld by Hydrex diver/technicianteams from all our offices; a look at the economic benefits that can begained by taking advantage of theHydrex propeller polishing services;and an interview with Hydrex Pro-duction Executive Dave Bleyenbergon how the practices of our TechnicalDepartment have evolved over the last fifteen years with the introduc-tion of several new production andcommunication technologies.

We hope you enjoy reading this issueof our magazine as much as we haveenjoyed producing it. Don’t be afraidto contact us if you have questions orcomments about the magazine or ifyou need our assistance with one ormore of your vessels. In the end that isstill our main goal: to help you keepyour ship sailing safely, economically,cleanly and on schedule.

Best regards,

Boud van Rompay

J ust a couple of months after weintroduced our new combined

Hydrex-Ecospeed magazine and aseries of white papers we are pleased to announce the launch of a new quarterly Journal of ShipHull Performance.

The purpose of the Journal of ShipHull Performance is to keep decisionmakers in the shipping industry in-formed with regard to the state of the science and art of underwater hullperformance, protection, monitoringand maintenance. The Journal willpublish reports, articles, interviews,news and information on the bestpractices in the field from the experts.More details on the content of thisJournal and information on how toreceive it free of charge can be foundfurther on in this magazine, right afterthe abstract of the third white paper.This white paper is titled Clean shiphulls without compromise and can bedownloaded in its entirety from bothour websites like previous papers.

The first feature article in this maga-zine deals with the effects of cavita-tion on ship rudders, caused by themovement of the propeller blades. We take a look at the damage that iscaused by this phenomenon and the

To receive a free copy, fax to:Hydrex N.V. +32 3 213 53 21or e-mail to hydrex@hydrex.be

Protection against cavitation and corrosiondamage safeguards rudders.

ISO 9001 certified

Message from Hydrexfounder Boud van Rompay

4

Over the last couple of yearsthere has been a substantial

increase in the number of enquiriesfor temporary underwater rudderrepairs, clearly showing the needfor a cost saving and lasting solu-tion. A great deal of effort goes intothe design and manufacture of rudders because they are such an important part of a vessel. If a rudder is not given the properprotection against cavitation andthe resulting erosion and corrosiondamage, the financial consequencescan be substantial for the owner.

Rudder, propeller and hull cavitation

is caused by the movement of the

propeller blades. A low pressure area

is created in the water around and

behind the blades as the ship gathers

speed. The faster the blades move,

the lower the pressure around them

becomes. At a certain point the water

reaches vapor pressure and forms

small bubbles of gas, a process known

as cavitation. When the bubbles move

into a higher pressure region of the

flow, they collapse and cause very

strong local shockwaves in the water,

which may be audible. All objects

close to the propeller which have an

uneven surface, such as parts of the

hull and the rudder, suffer from this

cavitation because these objects

disturb the flow of the water and cause

the bubbles to implode.

In itself cavitation, if it is monitored

correctly and kept under control,

presents no serious danger. But in the

long term, cavitation erosion appears.

The effect is comparable to a steel

tipped hammer that is repeatedly hit

against a steel surface at exactly the

same location; after a while damage

will occur. The cavities created by the

implosion of the gas bubbles will then

grow deeper and deeper and in the end

can eat right through the propeller

5

blade, the rudder or the hull. Large

eroded areas can occur this way.

Besides the mechanical damage

caused directly by the cavitation

process, it also opens the door for

corrosion damage.

A metal object in water will cause

electrolysis (chemical erosion of the

metal caused by an electric current

which is created due to a difference in

potential between the metal and the

surrounding water). This effect is

enhanced in salt water where a nega-

tive potential difference between the

ship and the water is created. If the

surface of a rudder has been damaged

by cavitation, the protective coating

will have worn away, leaving bare

steel. This accelerates the electrolysis

process and the steel of the rudder is

eroded.

Prevention of damage can startin the newbuild phase To avoid this, a system known as gal-

vanic cathodic protection is employed

on ship hulls. “Sacrificial” anodes

usually made of an alloy of zinc,

magnesium and aluminum are instal-

led on the hull. Because the sacrificial

Cavitation in progress.

Corrosion damage on rudders is often aconsequence of a lack of protection againstcavitation.

“The effect is comparable to a steel tipped hammer that isrepeatedly hit against a steel surface at exactly the samelocation; after a while damage will occur. The cavitieswill then grow deeper and deeper and in the end can eatright through the steel.”

Ecospeed is applied in only two layers andoffers lasting protection against cavitationand corrosion damage.

Increasing number of underwater rudder repairs reveals need for a lasting protection against cavitation

and corrosion damage: the Ecospeed solution

“There are number of factors that

dictate the performance of the coating

in service,” says Dr. Kattan, “Such as

proper paint selection, good surface

preparation, the correct coating appli-

cation to the ideal thickness within an

approved min-max dry film thickness

(DFT) range and a proper manage-

ment and maintenance system. If all

these things are optimized then the

corrosion prevention afforded by the

coating will be considerably enhan-

ced.”

Ecospeed prevents cavitationand corrosion damage What needs to be done is either

prevent the cavitation or make sure

that it has no damaging effect.

Ecospeed has been designed to give a

very thorough and lasting protection

against cavitation and corrosion. If

the cavitation cannot pierce the coa-

ting then no damage can occur. The

object that is coated with Ecospeed

will suffer less electrolysis or the

eating away of the less noble material.

Tests conducted in a flow channel

have confirmed that Ecospeed per-

forms extremely well under severe

cavitation. These tests were divided

into six stages during which the

anode has a lower potential than the

steel of the hull (it is made of a less

noble metal, meaning more suscep-

tible to chemical change), the anode

will suffer the damage instead of the

hull or other steel part of the ship.

“Cathodic Protection Systems are

normally designed to assume 5%

paint loss a year for the first 3 years

of the vessel life. This means that the

Impressed Current Cathodic Protec-

tion (ICCP) system offers corrosion

protection to those areas where paint

damage occurs as well as managing

the issues of dissimilar metals. It is

therefore important that the coating

can work in conjunction with such

systems.” Says Dr. Raouf Kattan, who

works as a coating specialist for

Safinah Ltd, a unique consultancy

focusing on marine and protective

coatings and staffed with experienced

coating chemists and naval archi-

tects/engineers.

According to Dr. Kattan a ship that is

designed to comply with appropriate

Classification rules must meet struc-

tural strength requirements. “These

rules will ultimately dictate the thick-

ness of steel for various parts of the

ship. To this steel thickness a corro-

sion allowance is added to allow for

natural corrosion of the steel over

time,” says Dr. Kattan. “The current

regime in place for Class regula-

tions assumes that there is no paint

applied to the vessel and the corrosion

allowance is designed to meet the sai-

ling life of the vessel at an assumed

annual corrosion rate. The used

coating has to protect this corrosion

allowance, as once the corrosion

allowance has gone, the vessel will be

on the limit of its structural strength.

So although the steel thickness may

be 20mm, the corrosion allowance

applies only to the top 2-3mm. If the

corrosion allowance goes, then the

owner is faced with costly steel repla-

cement, so it must be protected by

the coating that is applied,” says

Dr. Kattan. “Once the coating is

applied, regular maintenance is requi-

red to ensure it continues to provide a

suitable barrier to prevent corrosion

and hence should be subjected to a

proper maintenance regime.”

Corrosion damage repair and requiredrepaints of a rudder can make a drydockvisit much more difficult to plan.

“If you apply Ecospeed, a very thorough and lasting protection is given. If the cavitation cannot pierce the coating then no damage can occur.”

A rudder coated with Ecospeed is protected against cavitation and corrosion damage.

6

When such a vessel eventually comes

into drydock, maintenance of the

vessel’s stern area, especially cavi-

tation damage repair, can take a long

time. Because of the close proximity

of the rudder, the propeller and the

stern area, along with the strict proce-

dures concerning blasting, painting,

welding and propeller and stern tube

seal work, most of the repairs that

need to be done in these areas cannot

be performed concurrently. Painting is

then usually assigned to the end of the

schedule and as a consequence may

not get done at all or else prolongs the

stay in drydock. Taking into account

the tight drydock schedule of most

vessels this is often problematic.

With an Ecospeed application one

can avoid these problems from day

one because no full repaint of the

underwater hull will be needed during

drydocking. Ecospeed will remain

intact for the lifetime of the vessel

and is guaranteed for ten years. At

the most, touch-ups amounting to

less than 1% of the surface area will

be required. Planning the maintenance

of the vessel’s stern area therefore

becomes much easier.

coating was exposed to an increasing

pressure drop, creating a growing

cavitation force. Even after the last

stage no erosion was present on the

test patch coated with Ecospeed. The

tests were organized by the French

Ministry of Defense and were carried

out at a laboratory in Grenoble.

A variant, Ecospeed Strong, has been

developed especially for the protec-

tion of areas that are most often

subject to cavitation. It has the same

advantages as the regular Ecospeed

coating, but, due to its increased

strength, it is even more resistant

to cavitation. It is ideally used over

smaller areas that need extra protec-

tion, whereas the standard Ecospeed

coating is the best choice for the

larger parts of the hull less prone to

this kind of damage. Ecospeed Strong

provides the rudder with an impe-

netrable protective layer while its

flexibility enables absorption of the

forces that are produced by cavitation,

thereby preventing the damage nor-

mally caused by this phenomenon.

As a consequence of cavitation and

corrosion damage on their rudders

many ships are given a condition of

class. Such a condition of class can

have a great impact on the vessel’s

sailing schedule if for instance it is not

allowed to enter certain ports or needs

to go to drydock before a certain

period of time has passed. When the

vessel starts sailing after a drydock

visit everything usually goes well

until at the two and a half year mark

when the classification society requi-

res that ILDD inspections are carried

out. Often it is then discovered that the

rudder is actually in very bad shape.

Understandably the owner then wants

to try to hold off going to drydock as

long as possible and ideally until the

five year interval has passed.

Temporary repairs are carried out after

which the Class requires that a new

inspection be performed every three

months.

“Ecospeed will remain intact for the lifetime of the vesseland is guaranteed for ten years. Planning the maintenanceof the vessel’s stern area during a drydock visit thereforebecomes much easier.”

Because of the close proximity of the rudder, the propeller and the stern area most of therepairs that need to be done in these areas cannot be performed concurrently, prolonging the

stay in drydock.

ILDD inspections of rudders not protectedproperly often reveal damage right throughthe steel.

7

shipyard or drydock instead of the

other way round. The minimum over-

coating time is three hours, which

means that for smaller surfaces such

as rudders, propellers or bow thrusters

the two coats required can usually be

applied in one single day.

By removing the existing paint layers

and applying Ecospeed on the rudder

we can break the never ending cycle

of painting, suffering damage, having

to perform extensive repairs in dry-

dock followed by a full repainting,

again and again.

Conclusion If one takes into account the costs of

the temporary underwater repairs and

the regular inspections required by

a condition of Class until the next

drydocking, it becomes clear that the

investment in a coating system that

offers extra protection from day one

is easily won back. For this reason

more and more owners have Ecospeed

applied on a large part of their fleet

or have it put in the rudder specs of

their newbuild vessels. They invest in

the right coating system to protect

their rudders because they know that

the savings will be enormous.

The newbuild phase is the perfect time

to apply Ecospeed, but the coating can

also be used to protect vessels that are

already facing cavitation and corro-

sion damage. If the damage occurs,

Hydrex can work out a way to treat it

and prevent it from spreading, as is

demonstrated by the repairs discussed

in the articles on pages eighteen and

nineteen of this magazine. Operations

like those keep the vessel operational

until the next scheduled drydocking.

If required Hydrex can carry out a

small inspection in advance of the

docking to tell the ship owner the

exact condition of the hull and the

rudder to make the planning of the

drydock visit easier. We can make

sure that all equipment is present

when the ship enters drydock, that the

Ecospeed inspectors are ready and

that the application can start whenever

needed.

Ecospeed’s flexibility makes it easy to

adapt the application schedule to the

8

The Ecospeed coating remains intact even after several years of service.

An Ecospeed application can easily beadapted to the shipyard or the drydock’sschedule.

By removing the existing paint layers and applyingEcospeed on the rudder we can break the never endingcycle of painting, suffering damage, having to performextensive repairs in drydock followed by a full repainting,again and again.

Hydrex and Dutch stern seal specialist AEGIR-Marine began

working together in 2006, Hydrexas underwater specialists and AEGIR-Marine as manufacturer-indepen-dent stern tube seal specialists. Theycollaborate to carry out in-situunderwater stern tube seal repairsdeveloped by Hydrex for any manu-facturer and type of seal.

Using the Hydrex flexible mobdocks

and the state of the art seal bon-

ding equipment of AEGIR-Marine, fast

response to any emergency call is

guaranteed from the various workshop

locations worldwide. Hydrex divers

are regularly trained in the seal bon-

ding procedures at the AEGIR-Marine

facilities. Certified divers, assisted by

an AEGIR-Marine service engineer,

ensure the most reliable service avai-

lable. Hydrex has now received full

class acceptance from several major

classification societies to perform

underwater stern tube seal repairs in

cooperation with AEGIR-Marine.

This cooperation is beneficial for

Hydrex, AEGIR and the customers of

both companies. We can offer a full

range of stern tube seal and propeller

services, whether it entails the repla-

cement of worn seals, providing a new

running area for those seals or carry-

ing out other repair or maintenance

work on a stern tube seal assembly.

Damaged propeller blades can be

straightened with the Hydrex cold

straightening machine or cropped if

the damage is too extreme.

AEGIR-Marine has a very large stock

of spare parts which are checked,

rechecked and checked again by hand.

Therefore they can guarantee availabi-

lity of seals, spares and their engineers

on very short notice. Combined with

Hydrex’s large stock of equipment,

the partnership can offer a fast

response and be almost anywhere in

the world within 24 hours. The custo-

mer gets an optimal service, in a short

timeframe and at a good price.

Underwater stern tube seals Stern tube seal operations are perfor-

med with the use of the special

Hydrex and AEGIR-Marine: performing underwater stern tube seals

and propeller operations across the globe

9

Hydrex flexible mobdocks. These

mobile mini drydocks are used to cre-

ate a dry working environment under-

water in which drydock conditions are

simulated. Taking a vessel into an

actual drydock is very disruptive to

the ship’s operations and very expen-

sive. Finding an available drydock

is not easy; adapting a vessel’s sche-

dule so that it can go to drydock is

even more troublesome. Every day

that a ship needs to go off hire means

substantial losses, and the cost of

the drydock itself only adds to the

negative financial aspect of docking.

All this can be avoided by taking

advantage of the in-water services

offered by Hydrex with the full

support of AEGIR-Marine.

All Hydrex diver/technicians have

been trained by AEGIR-Marine engi-

neers as well as representatives of

major seal manufacturers, to replace

all types of seals. Our flexible mob-

dock allows us to do so underwater,

making it unnecessary to drydock.

These mobdocks are lightweight

equipment, like all equipment used by

Hydrex, so they can be transported

anywhere in the world in a matter of

days. Combined with the worldwide

network of Hydrex offices and service

stations this means that we can be at a

location and ready to assist a vessel

faster than one might think possible.

“Hydrex has received full class acceptance from severalmajor classification societies for underwater stern tubeseal repairs.”

The Hydrex flexible mobdock allowsHydrex to create drydock like conditionsunderwater.

accustomed to solving such problems,

our technical department worked out a

procedure that enabled the repair team

to carry out the job in the wet and after

that install the mobdock, replace the

seals and complete a full repair.

If a vessel has an oil leak it is also

often not allowed to sail on. The U.S.

Coast Guard for instance has very

strict policies concerning environmen-

tal risks and do not allow ships to sail

to a different location before the oil

leak has been permanently fixed.

Hydrex can make sure that a ship can

sail again while keeping the loss of

time to an absolute minimum.

Propeller modificationsA ship that has suffered damage to its

propeller blades might have severe

vibrations while sailing. The classi-

fication society might demand a repair

before the vessel is allowed to sail on.

By straightening the blades or crop-

ping them, Hydrex can restore the pro-

peller’s balance, resulting in a green

light from the class for the vessel.

Propeller blades can be straightened

with the Hydrex cold straightening

machine. After several years in ser-

vice, a new version was put into use at

the beginning of 2009. This enabled the

Hydrex diver/technicians to straighten

blades that have been bent over a big-

ger angle. The Hydrex research depart-

ment is constantly looking into ways

to develop this technique even further

and at this very moment a new update

is in its final testing stages.

After the flexible mobdock is installed

around a stern tube seal assembly,

our diver/technicians can enter the

mobdock and start dismantling the

assembly which can then be worked

on in dry conditions. This is essential

as bonding is not possible in the wet.

During an operation the diver/tech-

nicians inside the mobdock remain

in constant communication with the

team leader and the AEGIR-Marine

engineer on shore.

The most common reason for a seal

replacement is an oil leak. These are

often caused by fishing nets or ropes

that slip into the rope guard and get

tangled up in the seal assembly, cau-

sing damage to the seals. The running

surface of the seals can also be out of

limits, preventing a perfect sealing of

the assembly from the outside and

causing the oil leak. In some cases

more severe damage is suffered, and

replacing the seals or the running area

is not enough. But even in these cases,

which fortunately are very rare,

Hydrex and AEGIR-Marine can assist

ship owners.

A good example of this is the story of

a 38,000 dwt bulk carrier that had

suffered severe damage to her seal

assembly. Hydrex was asked to do the

repairs and replace the aft seals while

the vessel was in Piombino, Italy.

The rope guard was missing from the

seal assembly and some of the stern

tube flange bolts were seriously dama-

ged, while others had broken off. The

flange ring had mostly been scraped

off, presumably by the rope guard

before it had become completely

detached. There was also a gap

between the stern tube and the flange.

It was clearly a complicated repair but

our technical department worked out

a procedure to carry out the work

in-situ. Drydocking had initially appe-

ared to be the only option for the ship

owner. The stern tube seal assembly

had sustained damage that seemed too

extensive to repair underwater. Being

10

Hydrex diver/technician performing welding work on a rope guard.

“The stern tube seal assembly of a bulk carrier hadsustained damage that seemed too extensive to repair without going to drydock, but the Hydrex technicaldepartment worked out a procedure that enabled therepair team to carry out a full repair underwater.”

With the Hydrex cold straightening machineeven severely bent blades can be straightened.

communicate the exact dimensions

and position of the damage to the

Hydrex technical department super-

vising the operation. This is essential

because the calculations need to be

perfect to achieve an ideal result

with the repair. For this reason team

members work closely together with

AEGIR-Marine Propulsion. Hydrex

team members are not only divers, but

have experience in dealing with all

kinds of different situations and cir-

cumstances. They are trained to think

If the blade is damaged too severely

by ice of other floating debris, straight-

ening is not feasible. In such cases

cropping is the best option. This is

often done with the support of AEGIR-

Marine Propulsion Service (AMPS),

which focuses on propeller repairs

and modifications. If it is decided

that cropping is the only option, mea-

surements are taken and used to calcu-

late the exact radius of the area to be

cropped.

Both cropping and straightening

are done to restore the propeller’s per-

formance to as close to its optimum

condition as possible and to balance it.

This can help a vessel that is suffering

loss of speed due to an out-of-balance

propeller. Hydrex has been cropping

propellers since 1985 and straight-

ening them since 2000.

Prior to a propeller repair, a detailed

underwater inspection is carried out

by Hydrex diver/technicians who are

certified to make a full assessment of

the condition of the propeller and

HYDREX OFFICE FULLY OPERATIONALAT THE STRAIT OF GIBRALTAR

11

“Hydrex team members are not only divers, but have expe-rience in dealing with all kinds of different situations andcircumstances. They are trained to think with the people inthe technical department and the AMPS engineers.”

Hydrex SpainPoligono Industrial Palmones IICalle Dragaminas Nave N2911370 Algeciras • Spain

Phone: +34 956 675 049 (24/7)Fax: +34 956 921 914E-mail: info@hydrex.es

Our Hydrex office in Alge-ciras, Spain offers a large

variety of maintenance programsand repair works for ship ownersand the offshore industry, bothunderwater and above water.

Underwater maintenance servicesinclude hull cleanings, propellerpolishings, class accepted surveysand tail-shaft wear down readings.Underwater repair work consists of propeller repairs, shell platingcrack repairs, mobdock repairs,rudder pintle repairs and any typeof welding work.

Hydrex Spain also offers a widerange of above water operationsincluding accomodation ladderrepairs, anchor and chain work,cell guide repairs, crane repairs,

hatch cover repairs and mechanicaland engine works.

Hydrex Spain is fully geared tocarry out repairs at anchorage and in port. All operations are

certified by the classificationsocieties and are carried out byhighly qualified divers and tech-nicians all of which have extensiveexperience.

AEGIR-Marine BV was founded in

2000 by Ruud Muis and Hans Dekker.

Since then AEGIR developed into a

midsize organization with facilities

in The Netherlands, Shanghai and

Singapore. AEGIR started as a manu-

facturer-independent service company

for stern tube seals and this is still the

heart of the organization in 2011.

Although AEGIR has had many deve-

lopments and growth in a relative

short period, one thing did not change:

their approach and customer focus,

which is similar to the Hydrex way of

thinking.

“In 2005 we came in contact with

Hydrex Senior Project Manager René

Huybregts,” recalls Ruud Muis. “He

invited us for a meeting at the Hydrex

headquarters. Hydrex was at that point

developing new ways of repairing

stern tube seals underwater to broaden

the services offered to their customers

and had already carried out a few

jobs successfully. Hydrex’s flexible

mobdock technology in combination

with our brand-independence imme-

diately turned out to be a perfect

match. Together we could offer re-

pairs for all types of seals, whether

in drydock, on a trimmed vessel

or underwater.” Ruud says. “In June

2006 a cooperation agreement was

signed at the Poseidonia Exhibition in

Greece.”

“Since then the relationship has

remained a successful one for both

parties,” continues Ruud. “We all

know each other personally, from the

divers up to the managers. We can

with the people in the technical

department and the AMPS engineers.

The Hydrex diver/technicians can

assist in working out the best solution

and have the skill and experience

needed to implement the theoretical

solutions that have been worked out.

Hydrex does not only offer repair

services, but can also help customers

when they have the need for preven-

tive or other special custom projects.

At the end of 2010, preventive modi-

fications were made in Bremerhaven

to the blades of three ice-going sister

vessels. When several vessels of this

customer suffered damage and needed

cropping after the 2009-2010 winter,

the owner wanted to find a way to

prevent this from occurring on others

of his container vessels. When the

2010-2011 winter promised to be

equally harsh, he wanted to give the

blades extra strength and make them

less susceptible to damage from ice

or other debris. This was done by

modifying the blades to a very spe-

cific design that made them less

prone to damage while keeping the

performance of the propeller as close

to optimum as possible. The operation

was performed in close communi-

cation with both AEGIR-Marine Propul-

sion and the manufacturer of the

propellers.

Hydrex and AEGIR-Marine:offering solutions togetherThis is what Hydrex does if a custo-

mer calls us for assistance: we work

out a way of solving your problem.

This separates Hydrex from diving

companies. We not only implement

the solution, we have the know-how

and experience to devise that solu-

tion in the first place. Hydrex has

always strived to offer a wide range of

services. The customer has always

been the first concern. How can we

make sure that he receives the best

possible help in the shortest possible

time? How can we take the problem

out of his hands and solve it for him?

Our cooperation with AEGIR-Marine is

a part of this. Hydrex has more than

35 years of experience with repair

and maintenance operations in the

shipping and offshore industry.

AEGIR-Marine has over 20 years of

experience with stern tube seal and

propeller repairs in its ranks. It was

only a matter of time before the two

companies found each other and

started combining their experience

and skills.

AEGIR-Marine founder Ruud Muis.

“If a customer calls us for assistance, we work out a wayof solving their problem. This separates Hydrex fromdiving companies. We not only implement the solution, wehave the know-how and experience to devise that solutionin the first place.”

A propeller blade after preventive croppingto make it less prone to damage from iceimpact.

12

therefore openly discuss operations,

strategies and the future of our coope-

ration. We also pass on jobs to each

other; for instance if no diving work

is involved or if a customer needs

another service than the one we offer.”

Hydrex Shiprepair Manager, Martin

Pauwels remembers that AEGIR-

Marine already had a very compre-

hensive knowledge of seals and liners.

“This complemented our skills and

knowledge well, not only from the

point of view of the customers, but

also internally to give all our team

members a good understanding of

what exactly a seal assembly entails,”

Martin says. “There is a very good

synergy between the two companies.

Our cooperation has only increased

over the years. Having an AEGIR engi-

neer on a job is an added value.”

“At the beginning of 2009 AEGIR foun-

ded AEGIR-Marine Propulsion Services

(AMPS) in partnership with DeViss

Marine (lead by propulsion specialist

Martin Visser) and started offering an

extra service to its customers,” Martin

Pauwels tells us. “They hired speciali-

zed people with a lot of experience.

We were at that moment already offe-

ring the same service, but underwater.

We therefore immediately saw the

possibilities. Not only for the crop-

ping of propeller blades, but also for

the straightening of bent blades. Our

knowledge of this subject has been

vastly increased by working together

with them. This enabled us to develop

new techniques and equipment to

carry out bigger operations and repair

more comprehensive damage.”

Martin Visser has had a personal rela-

tionship with Hydrex from the begin-

ning of the nineties, independently

from AEGIR-Marine, when he gave

courses to several Hydrex team mem-

ber to teach them how to replace “face

type seals” underwater. This made

it very easy for both parties to start

working together on propeller modi-

fication operations after AMPS had

been founded. As part of the AMPS

team, Martin Visser supervises sup-

porting services of the entire drive

system of a ship, starting at the gear-

box and including propeller blade

modifications. “AMPS perform both

maintenance and repair work,” he

says. “We can make all hydrodynamic

calculations desired by the classifi-

cation society or the customer. Like

AEGIR-Marine, we are not restricted

to certain brands, but we do have

a specialization in LIPS/Wärtsilä

products.”

What happens after an enquirycomes in?“If we, for instance, get an enquiry

from a customer who has a ship with a

stern tube seal problem, we ask them

for all possible information; location,

type of ship, type of seal, technical

information and drawings,” says

Martin Pauwels. “All information is

then sent to AEGIR. They tell us if there

is any specific problem or aspect we

need to take into account for that

specific job. Then we generate a quote

which we send to the customer. An

AEGIR service engineer is always

present during an operation, not only

to assist our divers, but also to pre-

pare the seals and supervise their

bonding.

After the job has been coordinated

with the people in the engine room,

the Hydrex team leader and the AEGIR

representative go on board together at

the start of the job to discuss the

scope of the operation with the crew

members of the vessel. AEGIR also

performs the final tests and signs off

on their part of the operation.”

“A propeller modification operation

follows a slightly different route,”

says Martin Visser. “Ideally we recei-

ve the information about the damage

up front and then make a repair propo-

sal that will bring the performance

back as close to optimum as possible.

Our role during the actual operation is

purely a supportive one, to assist the

divers whenever needed. After the job

is completed we write a report. This is

supplied as an addition to the Hydrex

report.” This is confirmed by Martin

13

Hydrex Shiprepair Manager Martin Pauwels.

“Calculating the best cropping line makes it possible for the customer to know in advance what the result of the operation will be. He can then make an informed decision.”

AEGIR-Marine Propulsion Services propeller specialist Martin Visser.

mer. To be able to do this, all Hydrex

team members are trained and cer-

tified by AEGIR. This training certi-

ficate is renewed every year.”

ConclusionIn the end the customer is the real

winner of this successful cooperation.

Together Hydrex and AEGIR-Marine

can offer a full package: work on all

type of seals or propellers can be

carried out in dock, on a trimmed

vessel or underwater. This is a unique

service in the shipping business.

Both companies have expanded great-

ly over the last couple of years and are

still growing. “We keep on searching

for ways to improve our relationship

and the services we offer, in order to

keep us standing out from the rest,”

concludes Ruud Muis. “Despite the

fact that we remain two separate

companies we have established a very

direct and open communication and

cooperation. By offering an added

value to our customers, we make sure

that we are more than just the sum of

the two companies’ separate services.

Together we keep on looking for

ways to make the offered service even

better.”

Pauwels. “AMPS has the knowledge

and computer programs to make a

performance prediction and/or cal-

culation after a planned cropping. This

allows them to find the best cutting

line which in turn makes it possible

for the customer to know in advance

what the result of the operation will

be. He can then make an informed

decision. To do these calculations

AMPS needs the exact measurements

of the damage. These are taken by

the Hydrex diver/technician team

during a detailed inspection and used

by AMPS to make the required calcu-

lations.”

Martin Visser explains that “during a

propeller straightening operation, the

blade is also restored to as close to its

original form as possible. To be able

to do this the Hydrex team has to find

the cause of the bend. No calcula-

tions are necessary, but experience is

essential in doing this and AMPS can

support the team in this respect”.

“Propeller optimization is sometimes

also done to restore the performance

even if no real damage has occurred,”

continues Martin Visser. “After some

years of service an engine sometimes

loses some of its performance. By

calculating the possibilities of a pro-

peller optimization we can restore the

performance.”

Trained and certified diver/technicians “On a regular basis our divers are

given a course at the AEGIR head-

quarters or our headquarters,” says

Martin Pauwels. “With the aid of a

dummy, the divers learn to bond the

seal, but also what to do when opening

up an assembly. They learn to look

for damage on the liner, pieces that

are broken off and other problems.

Propeller repair training on the other

hand is given on the job, but an in-

house training course for propeller

operations is being established as we

speak to give divers a good reality of

what they can expect to encounter

during an operation.” Ruud Muis

confirms this. “Hydrex delivers the

divers, equipment and the mobdock,

and AEGIR helps ensure success and

complete satisfaction for the custo-

Training course given at the Hydrex headquarters by an AEGIR-Marine engineer in 2006 in thepresence of Hydrex Shiprepair Manager Martin Pauwels.

“In the end the customer is the real winner of this successfulcooperation. Together Hydrex and AEGIR-Marine can offer afull package: work on all type of seals or propellers can becarried out in dock, on a trimmed vessel or underwater.“

Hydrex technician cropping a propeller bladeto bring the propeller’s performance back as

close as possible to its optimum condition.

14

15

SHIP HULL PERFORMANCE TECHNOLOGY

Phone: +32 3 213 5318 Fax: +32 3 213 5321

info@ecospeed.bewww.ecospeed.be

Ecospeed ship hull perfor-mance technology lasts

the lifetime of the vessel. Theneed for full repaints duringfuture drydockings is elimi-nated.

An impermeable and extremelytough coating is combined withan underwater cleaning systemkeeping the hull roughness at anoptimum level and resulting in amajor saving in fuel.

Ecospeed is a 100% non-toxictechnology and is guaranteedfor 10 years. Its surface texturewill improve over time with re-gular inwater hull maintenance.

a

Hydrex around the world

AHydrex diver/technician teammobilized with one of the com-

pany’s workboats from the Algecirasoffice to perform a rope guard repla-cement, a propeller blade repair anda shaft wear-down reading on a 183meter tanker while the vessel was atanchor in the bay.

The team first installed a platform

around the stern to give the divers

access to the stern tube seal assembly

and the propeller. The operation was

then carried out in the dry while the

vessel was trimmed.

The divers then removed the old rope

guard and positioned the replacement

and bolted it in place. Next the team

performed an inspection of the propel-

ler and discovered a crack on the lea-

ding edge of one of the blades. The

crack was ground out and its edge was

smoothed. The operation was conclu-

ded with the performance of pintle

measurements. All three parts of the

operation were performed in one day,

avoiding any delay for the customer.

The rope guard of the vessel was replaced while the vessel was trimmed.

A crack on the leading edge of one of thepropeller blades was grinded out.

Propeller blade repairand rope guard

replacement in Algeciras

16

HYDREXOFFICES IN

INDIAREADY TOMOBILIZE

Hydrex has two fully staffedoffices in India. One in

Mumbai and one on Visakha-patnam, covering the East andthe West Coast of India.

Equipped with a complete arrayof Hydrex diving and repairequipment, both offices are readyto carry out any necessary repairand maintenance work and provi-de preventive as well as problemsolving services.

All operations will be carried outby professional Hydrex teams,trained and qualified to performcomplex technical tasks under-water. All procedures are fullyapproved by all major classifica-tion societies.

Hydrex Mumbai Phone/Fax:+91 222 2046 988 (24/7)E-mail: mumbai@hydrex.be

Hydrex Vishakhapatnam Phone/Fax: +91 891 2711 863 (24/7)E-mail: vishakhapatnam@hydrex.be

At the end of last year the rud-der of a 275 meter container

vessel was coated with Ecospeed in Naples, Italy. The rudder had suffered cavitation damage and theowner chose the coating systembecause it will protect the rudderagainst similar damage from now on.

A great deal of effort goes into the

design and manufacture of rudders

because they are such a key part of a

vessel. Therefore they ought to be pro-

tected properly. Ecospeed’s durability

provides this protection because the

coating will remain intact for the life-

time of the vessel and is guaranteed

for ten years.

The rudder will not have to be repain-

ted during future drydockings, nor

will extensive repairs be needed.

Planning the maintenance of the ves-

sel’s stern area therefore becomes

much easier. The smoothness attained

by the coating also provides optimum

hydrodynamic conditions for rudders

to operate at maximum efficiency. The

ship's performance remains stable and

the owner's investment is secured.

Ecospeed application in Italy will safeguardrudder from corrosion damage

Surface preparation allows for a fast andeasy application of Ecospeed.

Ecospeed is applied in only two layers aftergrit blasting.

17

FULLY OPERATIONAL IN NORTH AMERICA

Hydrex US is prepared tomobilize immediately and

is capable of efficiently servicingoffshore units and ships callingports in Canada, North, Centraland South America as well asthe Caribbean.

Saving significant amounts oftime, trouble and expense throughits on-site work, Hydrex servicesrange from a complete review of a vessel’s external condition allthe way through to highly tech-nical major repairs or replace-ments of a ship’s external under-water equipment and machinery.

Repairs to thrusters, propellers, rud-ders, stern tube seals, damaged or cor-roded hulls and all other underwaterservices are done by professional

teams trained and qualified tocarry out complex technical tasksunderwater while the vessel is in-situ.

Hydrex US 604 Druid Rd, Clearwater, FL 33756

Phone: +1 727 443-3900 (24/7)Fax: +1 727 443 3990info@hydrex.us • www.hydrex.us

Hydrex performed all operations

under DNV requirements which were

verified by an attending surveyor.

The diver/technician team rotated

in shifts to finish both repairs in the

shortest possible time and avoid any

unnecessary delays for the vessel.

Last month a Hydrex diver/tech-nician team performed a crack

repair on the pintle area of the rudder of a 181 meter tanker andperformed a detailed inspection ofthe stern tube seal assembly of thevessel while it was berthed in Ghent.Following this inspection the teamreplaced the worn seals and installeda spacer ring, thus creating a newrunning area for the seals.

Prior to the operation the vessel was

trimmed as much as possible. The

Hydrex team then build a scaffolding

around the rudder pintle and the stern

tube seal assembly. Next they remo-

ved the rope guard and the damaged

areas of the outer plating of the rudder.

This allowed them to perform an in-

spection of the stern tube seal assem-

bly and start the repair in the rudder.

While the team prepared a first insert

plate on shore, the inspection of the

seal assembly revealed that the seals

were worn and needed replacement.

Next they installed the first insert and

secured it while the second plate was

prepared. Simultaneously another part

of the team opened the stern tube seal

assembly and it became clear that they

needed to renew the running area of

the seals as well. The team did this by

installing a new spacer ring on the

stern tube flange after which they

replaced and bonded the three seals.

By this time the second insert on the

rudder had also been fitted and welded

according to the approved procedures.

Independent ultrasonic testing confir-

med that the insert repair was success-

ful. The only thing the team needed to

do to conclude the rudder repair was

grinding away a small crack located

on the other side of the rudder. By

then the rest of the team had closed

the stern tube seal assembly and an oil

test had been performed, verifying the

seal repair had been carried out with

satisfactory results.

Rudder and stern tube seal repair on tanker in Ghent, Belgium

Certified welding procedures are followed during all Hydrex operations.

Cut away area ready for installation of newinsert plate.

Three stern tube seals were replaced andprovided with a new running area.

Welding on new rudder insert plate.

18

19

Heavy corrosion was found on all parts around the rudder

plating of a bulk carrier togetherwith penetrations into the rudder’sbody below the rudder horn. AHydrex diver/technician team there-fore mobilized to the port of Alge-ciras where the vessel was berthed.

After a thorough underwater inspec-

tion, the team prepared three insert

plates which were then installed over

the areas that had suffered the most,

and secured with full penetration

welding. The divers also applied

epoxy over the cavitated spots. This

temporary repair allowed the vessel to

keep sailing until the next scheduled

drydocking.

Underwaterrudder

repair inAlgeciras

Inspection of heavy corrosion damage onrudder of bulk carrier.

One of three inserts plates installed oversubstantial corrosion damage on rudder.

IN-SITU BOW THRUSTEROPERATIONS

The Hydrex lightweight flexi-ble mobdocks are designed

to be easily transported aroundthe world and are used to close off the thruster tunnel on bothsides, allowing divers to performrepairs and other operations in adry environment around the bowthruster unit.

This technique enables them toreinstall the propeller blades of an overhauled thruster inside thethruster tunnel after the unit hasbeen secured or replace the bladesor seals and perform repair work on

a specific part without removing theunit.

Since the development of this flexi-ble mobdock technique, numerousthruster repairs have been carriedout by Hydrex diver/techniciansaround the world.

There is no need to send the vesselto drydock as all operations can be carried out in port or while thevessel is stationary at sea. Normalcommercial activities can thereforecontinue without disruption.

Phone: + 32 3 213 5300 (24/7) hydrex@hydrex.beFax: + 32 3 213 5321 www.hydrex.be

To stop oil from leaking from thestern tube seal assembly of a

reefer vessel, a Hydrex diver/tech-nician team was mobilized to per-form permanent repairs on the vessel during its scheduled stop inPort Huemene, Los Angeles, U.S.A.

The operation started with a thorough

underwater inspection of the stern

tube seal assembly, followed by the

removal of the rope guard and instal-

lation of the Hydrex flexible mobdock

around the stern tube seal assembly.

This created a dry underwater envi-

ronment in which the diver/techni-

cians could remove the damaged seals

one by one and replace them with new

ones. After these were bonded, the

entire assembly was put together

again and wear-down measurements

were carried out, revealing that the

repair was successful. The flexible

mobdock was then removed. Finally

the rope guard was reinstalled, con-

cluding the repair.

The team worked in shifts to perform

the stern tube seal repair in the shor-

test possible time. By keeping his ves-

sel out of drydock, a lot of time and

money was saved for the customer.The Hydrex flexible mobdock allows us to

create a dry underwater environment.

Underwater stern tube sealreplacement in Los Angeles

and under surveillance of a Bureau

Veritas surveyor.

The customer noted that he was

“impressed by the professionalism of

our entire team”, despite the fact that

“the weather was very harsh and not

simple and easy for the team.”

After a brand new 366 metercontainer vessel had a very un-

fortunate collision on its way to itsnext stop in Hamburg a Hydrexteam was assembled to perform aninspection of the suffered damage.Luckily the vessel could continue itsjourney to Hamburg where it wasmet by the inspection team.

At the time of the accident a snow

storm was passing over North Western

The inspection was carried out in harshweather conditions.

Europe, preventing a direct mobili-

zation. The following morning an

inspection team left from Antwerp

in the early morning and arrived at

the vessel around noontime the same

day. Despite the severe weather con-

ditions, the team carried out the under-

water inspection in safe conditions

Christmas collision damage inspection of large container vessel in Hamburg

The collision damage luckily did not prevent the ship form sailing on to its next stop.

20

Hydrex West Africa is situa-ted in Port Gentil, Gabon

right next to Cape Lopez Bay.Working closely together withthe headquarters in Antwerp theoffice can benefit from Hydrex’ slong tradition in the ship repairand offshore industry.

Port Gentil is a general and bulkcargo port. It is the only port on theGabon coast with a bunkering ser-vice. The sheltered bay is ideallysuited for in-water work. Thiscombined with its central locationon the African West coast makes it the ideal place to have repair or maintenance work carried outon a ship, barge or rig in optimalcircumstances.

Hydrex West Africa can mobilizeteams immediately to service ves-sels and offshore units in Port

Gentil or any other suitable locationin West Africa. A good example ofthis is the recent removal, repair andreinstallation of a 40 ton swing-upazimuth thruster of an offshore crane

barge that was servicing rigs in anoil field off the coast of Gabon.The entire operation was perfor-med while the unit stayed at ancho-rage just outside the oil field.

HYDREX WEST AFRICA IN PORT GENTIL, GABON

Hydrex West AfricaSis TLC/ Cité Shell BP 2160 Port Gentil - GabonPhone : +241 04 16 49 48 (24/7)E-mail: westafrica@hydrex.be

When both the port and star-board side impressed current

anodes on a 286 meter containervessel were worn out and needed tobe replaced, Hydrex sent a divingteam to Le Havre to perform theoperation.

The customer passed on all the ne-

cessary information to the Hydrex

technical department and after de-

tailed preparations the equipment was

loaded onto one of the trucks at the

Hydrex headquarters in Antwerp and

transported to Le Havre. The Hydrex

team arrived on the site and carried

out an inspection on the port and

starboard side ICCP anodes which

revealed that the anodes on both sides

were in poor condition. They were

therefore removed and replaced with

new ones by the Hydrex diver/tech-

nician team, restoring the vessel’s

protection against corrosion.

Impressed current anode replacement in Le Havre

When an anode is worn a vessel becomes very susceptible to corrosion damage.

Replacing the anodes renews the protectionagainst corrosion.

21

pulsive efficiency can be calculated.

This shows that significant losses

resulting from blade roughening can

be regained by cleaning and polishing

of the blades.

Fuel savings of up to 5% can be

gained if a polishing is performed

on a propeller after one to two years

in service. Exact figures depend on a

number of factors such as operating

conditions and propeller design, but

it is recommended to perform propel-

ler polishing at regular intervals to

avoid losing propulsion efficiency.

This keeps the propeller in optimum

An observed reduction in shipperformance is readily associa-

ted with the condition of the ship’shull, but the effect of the propellersurface condition is often overloo-ked. Nevertheless, the effect can besignificant. In economic terms, ahigh return for a really low invest-ment can be obtained by propellermaintenance.

When considering the propeller sur-

face condition, a distinction has to be

made between fouling and surface

deterioration. The effects of propeller

fouling in terms of a power penalty

are much greater than those of surface

deterioration. Research has shown

that propeller fouling can quickly

reduce the delivered horsepower

by 20%. While rough propellers can

be as destructive of fuel economy

as rough hulls, the remedy is much

cheaper.

Propeller roughness is most easily

measured underwater by divers using

a comparator gauge, whereby the pro-

peller surface is compared to surface

finishes of known roughness. The

predominant effect of an increase in

roughness of the propeller blades is

an increase in the propeller torque,

thereby lowering the propulsive effi-

ciency. By using a propeller perfor-

mance analysis tool the losses in pro-

The value of regular underwaterpropeller polishing

Propeller blades prior to polishing.

"Research has shown that propeller fouling can quicklyreduce the delivered horsepower by 20%. While roughpropellers can be as destructive of fuel economy as roughhulls, the remedy is much cheaper."

Propeller blades after polishing. Hydrex diver during propeller blade polishing.

22

zed by the Hydrex technical service

teams and will be tailor-made to fit

your and your vessel's needs. With the

Hydrex special in-house developed

underwater equipment propeller polish-

ing can be carried out in a very short

timeframe. This makes it possible for

you to have underwater propeller

polishings or any other maintenance

work carried out whenever you need

it, where you need it and without any

organizational hassle.

operational condition and can keep a

vessel’s fuel consumption as low

as possible, leading to significant

financial savings.

Hydrex offers propeller polish-ings on a worldwide basis

Throughout the years Hydrex has

invested in the development of under-

water equipment that allows us to

offer propeller polishing and other

maintenance services on a global

basis through a network of offices and

stations strategically located around

the world.

Like all Hydrex maintenance services,

propeller polishing are available both

as one time operations and as part of

tailor-made service contracts. This

gives shipowners the chance to be in

total control of their ship's propeller

condition and consequently its perfor-

mance. We offer a very practical

concept that has been developed over

the last 10 years. Through continuous

control of the hull condition, we will

reduce both the fuel consumption and

technical repairs.

Carrying out preventive cleaning and

other maintenance actions will keep

your vessel as close as possible to its

most advantageous condition and will

even allow us to increase the optimum

performance of the ship over time as

more data becomes available in the

hull monitoring program.

Based on your sailing schedules, these

operations will be planned and organi-

Hydrex diver polishing propeller blades.

"Through continuous control of the hull condition, we willreduce both the fuel consumption and technical repairs."

23

24

Turnkey underwater solutions for the offshore industry

Phone: +32 3 213 5300 (24/7)Fax: +32 3 213 5321E-mail: hydrex@hydrex.be

www.hydrex.be

Underwater solutionsavoid drydocking

Worldwide network of officesand service stations

Fully trained and certified diver/technicians

Offshore repair andmaintenance services

Ship hull cleaning equipment designedspecifically for offshore operations

Fast response centers withinstant mobilizable equipment

25

It is fair to say that concern aboutthe impact human activities have

on this planet is growing every deca-de, possibly every year. Damage tothe marine environment, oceans andwaterways, ports, estuaries andrivers, along with the emission ofgreenhouse gases (GHG) such asCO2, NOx, SOx into the earth’satmosphere by the burning of fossilfuels to drive ships, are a significantpart of this concern.

While other aspects of ships and

shipping play their own part in this

environmental concern, a key factor

is the underwater ship hull. This is

subject to biofouling as vegetable and

animal matter naturally attaches to a

ship’s hull. If not dealt with effective-

ly, this can lead to three main sources

of damage to the environment:

1. A fouled hull carries with it a fuel

penalty. The worse the fouling,

the slower the ship will sail at a

given RPM. Or, put another way,

the more power will be required to

keep the ship sailing at a given

speed. This means higher fuel

consumption. Depending on the

degree of fouling, this can be as

much as 80 - 100% more. This

means higher fuel consumption

and therefore a greater volume of

greenhouse gas (GHG) emissions

which pollute the earth’s atmos-

phere.

2. The misguided attempt to deal

with the fouling by applying to the

hull a coating designed to poison

the marine life before it can attach

itself, or to kill it when it has atta-

ched itself, leads to the leaching

of very significant concentrations

of biocides or poisons into the

oceans and waterways. These

toxic substances have been shown

to harm many varieties of marine

life and do not restrict their effects

to those species which comprise

biofouling. They contaminate the

food chain. They have an array of

harmful effects on many forms of

marine organisms and, through the

food chain, to animals and humans.

3. If marine biofouling is not dealt

with correctly, the accumulated

fouling poses a risk of transferring

invasive non-indigenous species

(NIS) around the world with con-

sequent damaging effects to local

marine life and a reduction of bio-

diversity. One of the key means of

translocation of NIS is the fouled

hulls of ships.

These three factors are all of grave

concern to the environment and to

the shipping industry. Shipowners

and operators will sooner or later have

to act to reduce or remove all three

risks, if not out of a sense of respon-

sibility for the environment, then as

a result of legislation or regulations,

some of which already exist and

more of which is likely to become

stricter and more far reaching.

There is little point providing a “solu-

tion” to one or even two of the three

factors mentioned above if this in-

volves the sacrifice of the other point

or points. For example, coating a

ship hull with toxic substances in an

effort to keep the hull free of fouling

may appear to mitigate the risk of

spreading NIMS and may reduce the

level of fouling and therefore lessen

the fuel penalty to some degree, but

it involves a huge compromise – the

poisoning of the oceans, damaging of

marine life and contamination of the

food chain.

Why bother to take great precautions

to protect a port from an invasive non-

indigenous species if this requires

widespread pollution of that port

through heavy metals and a variety of

toxic herbicides and pesticides?

Any valid solution to the environ-

mental hazards resulting from ship

hulls plying the oceans, must take

into consideration all three sources

of environmental harm. The ideal

solution would involve the least com-

promise or, better yet, no compromise

at all.

This White Paper, “Clean Ship Hulls

Without Compromise,” examines

these factors in detail and presents the

only approach which is economically

feasible (and in fact very beneficial)

and satisfies all three points of en-

vironmental impact in the best possi-

ble way. This approach uses existing,

tried and tested technology which is

currently in use and available.

Through this approach, shipowners/

operators, port authorities, environ-

mental protection agencies, shipping

Hydrex White Paper No. 3Clean ship hulls without compromiseBest approach to safeguarding of the marine environment

through correct hull protection and maintenance

regulatory bodies and government

officials will all benefit through the

following :

1. Elimination of the risk of sprea-

ding invasive non-indigenous

marine species

2. Dramatic reduction of fuel con-

sumption and therefore GHG

emissions

3. Reduction to zero chemical pollu-

tion of the oceans, ports and

inland waterways through the use

of non-toxic coatings.

While this approach only concerns the

underwater hulls of vessels, the world

fleet is large enough today for this

alone to have a considerable benefici-

al impact on the environment.

The White Paper includes a detailed

case study of a major port and some of

the shipowners and operators who are

adopting this approach successfully.

The fear exists that any actions taken

to reduce environmental impact will

be expensive and commercially de-

leterious to industry. In this case,

the approach advocated in the White

Paper also amounts to a major reduc-

tion in costs through fuel saving,

eliminating unnecessary time off-hire

time and time in drydock, and the eli-

26

mination of expensive hull recoating

along with the preparation required.

The White Paper, “Clean Ship Hulls

Without Compromise,” can be read and

downloaded at www.hydrex.be and

www.ecospeed.be and is available in

printed form at no charge.

ISO 9001 certified

In addition to publishing a seriesof white papers on underwater

ship hull protection, monitoring,maintenance, cleaning and relatedissues of a commercial, perfor-mance and environmental nature,Hydrex is pleased to announce thelaunch of a new quarterly Journalof Ship Hull Performance.

The first issue of the new Journal was

published in January 2011. It is avai-

lable in PDF format as well as in a

printed version. The Journal will be

emailed or mailed out free of charge to

all those requesting it.

The purpose of the Journal of Ship

Hull Performance is to keep decision

makers in the shipping industry infor-

med with regard to the state of the

science and art of underwater hull

performance, protection, monitoring

and maintenance. This includes ship-

owners, operators, navies, government

officials concerned with shipping and

the environment, port authorities, aca-

demic institutions, trade organizations

and the maritime media. The Journal

will publish reports, articles, inter-

views, news and information on the

best practices in the field from the

experts, presented in easily understood

terms for decision makers and exe-

cutives rather than for scientists or

technicians (although scientists and

technicians may also find the data

presented useful and interesting).

If you are interested in receiving the

Journal of Ship Hull Performance on a

regular basis, you may subscribe on-

line at www.ShipHullPerformance.organd request electronic and/or printed

issues of the Journal when it is publis-

hed as well as the Hydrex White

Papers. Subscription is free and enti-

rely without obligation. You may

cancel at any time. You may also

email us at publications@hydrex.usto subscribe, provide feedback or for

any questions regarding the Journal.

We welcome dialog, letters, feedback,

suggestions and contributions.

We hope you will find the Journal of

Ship Hull Performance an indispen-

sable source of useful and interesting

information, highly relevant to your

job.

Let us have your opinions and ideas.

The new quarterly Journal ofShip Hull Performance

27

and that’s how I was introduced to

Hydrex.

I was standing on a ladder doing

some chores when René (Huybregts:

Hydrex Senior Project Manager)

called and asked me if I was available

for a job. The next day I was picked

up by a Hydrex van and was off for

a week to Le Havre. After that I

was immediately sent to another job.

It was only after three weeks that I

saw the Hydrex premises for the first

time. From then on it went very fast.

H: You quickly rose through theranks from student diver to team leader. How did that happen?DB: I guess because I took my respon-

sibility seriously. Hydrex appreciated

this very much. I was always very

curious and I wanted to know and

learn everything I did not know yet.

After three years I was promoted to

team leader which I remained for four

years. After I became father of twins

I could not be away from home for

long periods. By then Hydrex had

asked me on a few occasions if I

would be willing to make the transfer

to Technical Services and I took them

up on the offer. Looking back I would

have liked to remain a diver for a

while longer, but you have to be able

to adapt yourself to the circumstances.

I made the decision and without loo-

king back I went in a new direction.

I started as René’s assistant, doing pre-

parations prior to a job and finishing

off the paperwork after the operation

had been carried out. I generated

invoices and made sure that the teams

could to their job in the most efficient

way. I became a contact point for

divers who needed help or assistance.

The Hydrex divers are wellknown by customers around

the world. They arrive with all theneeded equipment to assist yourvessel and make sure that the desired maintenance or repair workis carried out to your satisfaction.The Hydrex Technical Departmentperforms a great deal of advancepreparation for these jobs to ensurethat they are smooth, rapid and successful. During the operationthey also stay in direct communi-cation with the diver/technicianteams to assist them where requiredand provide them with anythingthey might need.

Dave Bleyenberg, who has recently

celebrated is fifteenth anniversary

working for Hydrex, coordinates all

ongoing jobs and as Head of the

Technical Department makes sure that

the communication between the diffe-

rent Hydrex offices goes as smoothly

as possible.

Hydrex: Can you tell us what you didbefore joining Hydrex and how yougot to know the company?Dave Bleyenberg: I got a technical

degree in high school before I had

to fulfill my army duty. After only a

couple of weeks I opted for fairly

heavy education during my enlist-

ment: underwater scout for The Royal

Dutch Army Divers. I already had a

background in recreational diving and

the demanding training appealed to

me. I am a very active person who has

always liked practicing sports and I

wanted to use this as much as possi-

ble. Immediately after the start of the

training I felt this was the right path

for me. When the course was comple-

ted I got the opportunity to stay with

The Royal Dutch Army Divers at

the training facilities. I stayed there

from 1990 until 1994 with temporary

annual contracts. In this period of time

I also took the courses in commercial

diving. After four years I was offered

a long term contract, but I wanted

something else. I started applying to

diving companies close to where I live

An interview with Dave Bleyenberg, Hydrex Production Executive

Dave, Bleyenberg, Hydrex ProductionExecutive.

28

From a call for assistance to a finished operation

"I was standing on a ladder doing some chores whenHydrex called and asked me if I was available for a job.The next day I was picked up by a Hydrex van and was offfor a week to Le Havre."

H: This has probably also allowedyou to bring down the response timetowards the customer?DB: If a customer calls us today for an

insert repair we can have a team on

the road within the hour, give or take.

In the past you needed a couple of

days to make arrangements. Getting

certified steel at your disposal, for

one, took some time. In 2011 we have

a very large stock of equipment like

that readily available at our depots.

In the past, new cofferdams needed to

be made for every single operation,

now we have them on our shelves.

We have grown so much that we have

all this at our disposal. This allows us

to respond much faster. It is also a

blessing for us to be able to go to our

Fast Response Center knowing that

a large part of the needed equipment

for a job is already there. Over the

years you learn what you need and

what is most difficult to get and thus

best to have ready at your fingertips.

H: As you mentioned, Hydrex hasgrown considerably since you joinedthe company. How has this affected the way the Technical Departmentoperates?DB: When I started working in the

office, we did about three hundred

operations each year and each job file

was prepared and finalized by me.

Since then Hydrex has opened several

new offices and the number of jobs

carried out each year has multiplied

many times. We also have many more

teams on the road all around the planet

at any point in time. A further aspect

that complicates matters is the fact

that the range of services offered to

our customers has grown considerably

and now includes more complex

there on time. In most cases this does

not raise any problems. If the client

then confirms the operation, the job-

file is given to the Technical Depart-

ment. We then start gathering a team

and begin making the preparations.

Sometimes assembling a team requi-

res a lot of work and can be very

hectic. In quieter periods this is far

easier. You have to have a very good

line of communication with both

teams on the road and teams not on

the road.

H: I assume the digital era is a bigblessing for your job?DB: Ten to fifteen years ago you con-

tacted headquarters, which was the

only office then, after you finished a

job. They then arranged a flight for

you. Possibly you got a new assign-

ment when you went to pick up your

flight details, but this was very limi-

ted. We had no cell phones, no e-mail,

no computers and only very limited

communication options. If you were

sent to Africa and encountered chan-

ges, you couldn’t call the headquar-

ters 24 hours a day. Now we are in

constant communication with the

teams. Working in the Technical

Department is a lot about being able

to make predictions from a distance.

I have been growing in this aspect

and try to be as future oriented as

I can. I am now coordinating the

production of the entire Hydrex

group. This would have been very

difficult to orchestrate fifteen years

ago. In that respect, new technologies

like e-mail, cell phones and Skype are

a blessing for me. They allow me to be

in contact with all our offices almost

at the same time.

29

H: Many members of our TechnicalDepartment have been divers andhave a good idea of the reality of ajob. How important is this for a com-pany like Hydrex?DB: Experience is a big plus. I have

seen the whole planet during my eight

years under water; I know every

aspect of a job and a diving team and

experienced all kinds of different

situations. You know what a diving

team needs and goes through, how to

avoid potential loss of time and how

to even gain time. You can answer the

diver team’s questions over the phone

if they are facing similar situations

as you have faced. This is helpful

during the preparations and allows

you to remove obstacles while the job

is in progress. Someone without this

practical experience would have a

much longer learning process.

H: Can you guide us through thetypical steps that take place after anenquiry comes in?DB: If our sales team receives a job

enquiry, they immediately check with

us to see if we can carry out the ope-

ration. We then check to see if we

have the personnel available, whether

the location is suitable and whether

we can get all the required equipment

"If a customer calls us today for an insert repair we canhave a team on the road within the hour, give or take. We have a very large stock of equipment readily availableat our depots. This allows us to respond much faster."

Dave in 1998 during a stern tube seal repaircourse given by John Crane Marine.

30

left on his own. As a company you can

give your divers a safe point on which

to fall back if required. You need to

have good relationships and lines of

communication with your team. If a

diver requests something, you have to

try to find a solution and provide him

with what he needs. This can be some-

thing he needs on the job, but might

also be help with a personal situation

that affects the job.

H: What do you feel makes Hydrexstand out from the rest?DB: Efficiency combined with a con-

stant quality. Customers know that

they will be receiving the same result,

no matter the difficulty. We have al-

ways put a lot of effort into research

and development to offer solutions for

even the most difficult problems. You

need experienced and well trained

personnel for this, another important

factor that makes Hydrex not just

another diving company.

repairs. These kinds of jobs need more

paperwork and planning. Also we see

stricter demands from port authorities,

terminals and an increase in required

certificates. If you take all this into

account, you immediately understand

why we have expanded the Technical

Department with people who have

the skill and experience to handle

bigger and more complex jobs that

span longer periods.

H: How do you see the growth of theHydrex diving team?DB: As something very positive. I have

always tried to work towards having

teams that are future oriented. If you

leave new divers at the depots

constantly they have no opportunity

to grow. During less busy periods we

can now send a team that contains a

good mix of very experienced as well

as student divers. This way we can still

maintain the same quality and at the

same time allow new divers to grow,

which in turn enables our company to

grow.

In order to keep on offering our custo-

mers the same quality despite the

constantly growing number of divers

working for Hydrex and the broa-

dening range of available services,

I have also helped to establish in-

house courses that student divers can

take. This way all divers in all offices,

whether in America or Gabon, have

done the same courses and are capable

of carrying out jobs in the same way

and with the same level of quality

all around the world. This is very

important for our customers who need

to know that they will receive the

same equipment and quality, whether

from a team in India or in Spain.

H: The chief divers are telling methat they really appreciate that youguys listen to what divers have to sayduring and after a job.DB: People who join our production

department need to know what is

going on and what potential situations

our teams are facing. If you want to

be able to provide back-up when

someone needs it, you have to learn

the backgrounds of all kinds of job

and how to assess situations. Com-

munication is essential in achieving

this. A diver likes to feel that he is not

I have also helped to establish in-house courses that student divers can take. This way all divers in all offices,whether in America or Gabon, are capable of carrying outjobs in the same way and with the same level of quality allaround the world."

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 bestraightened underwater, allowingthe ship to return to commercialoperations without the need to drydock. Blades can be broughtback close to their original form,restoring the propeller’s optimumefficiency.

The cold straightening machineshave been in use for quite some timenow but the Hydrex research depart-ment has been looking into ways to

expand the technique even further toimprove our services. A new versionof the straightening machine wasrecently put into practice. It is com-patible with the existing models andis used to restore more severely bent propeller blades to their originalcondition.

COLD STRAIGHTENING OFSEVERELY BENT

PROPELLER BLADES

31

Hydrex has developed anentirely new method ena-

bling permanent repairs ofrudders without drydockingthe ship. Permanent repairswere hitherto not possible andships had to drydock in case amajor defect was found. Thenewly designed equipment islightweight and can be mo-bilized very rapidly in ourspecial flight containers. There-fore this new service is nowavailable worldwide.

Major defects on rudders very

often cause unscheduled dry-

docking of ships. The new

method designed by our techni-

cal department allows engineers,

welders and inspectors to per-

form their tasks in dry condi-

tions. Class approved permanent

repairs in-situ, without moving

the ship, are now possible

and commercial operations

can continue. Steel repairs and

replacements can be performed

and pintle and bushing defects

can be solved without the loss of

time and money associated with

drydocking.

The equipment can be mobilized

within hours to any port in the

world and is available for rapid

mobilization from the Hydrex

headquarters in Antwerp.

Permanent rudder repairs now possible without drydocking

Keeping ships in business

Hydrex underwater tech-nology and services pro-

vide high quality solutionsto the repair and replace-ment problems encounteredby ships and offshore ves-sels.

We deliver a complete line of

services that may reduce oravoid off-hire time entirely.From major projects to simpleinspections, Hydrex has theworldwide facilities and capa-bility to meet your demands.

Drydocking is not necessaryso time, trouble and expense

are saved by doing work in-situ. Hydrex services coverhighly technical major repairsor replacements of a ship’sexternal underwater equip-ment such as thrusters, pro-pellers, rudders, stern tubeseals and damaged or corro-ded hulls.

www.hydrex.be

Headquarters Hydrex N.V. - AntwerpPhone: + 32 3 213 5300 (24/7)E-mail: h y d r e x @ h y d r e x . b e

Hydrex Spain - AlgecirasPhone: + 34 (956) 675 049 (24/7)E-mail: i n f o @ h y d r e x . e s

Hydrex LLC - Tampa, U.S.A.Phone: + 1 727 443 3900 (24/7)E-mail: i n f o @ h y d r e x . u s

Hydrex West Africa – Port Gentil, GabonPhone: + 241 04 16 49 48 (24/7)E-mail: w e s t a f r i c a @ h y d r e x . b e

Hydrex India - MumbaiPhone: + 91 222 2046 988 (24/7)E-mail: m u m b a i @ h y d r e x . b e

Hydrex India -VishakhaptnamPhone: + 91 891 2711 863 (24/7)E-mail: vishakhapatnam@hydrex.be