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 [email protected]
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: [email protected]
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
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: [email protected]
Hydrex Vishakhapatnam Phone/Fax: +91 891 2711 863 (24/7)E-mail: [email protected]
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 [email protected] • 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) [email protected]: + 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: [email protected]
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: [email protected]
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 [email protected] 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: [email protected]