Magazine 167 - Hydrex Underwater Technology

Magazine 167 - Hydrex Underwater Technology

Number 167

Underwater cleaning and inspection of chord and spud can connections of jack-up rig . . . . 4 - 5

Underwater maintenance work carried out on drilling vessels in Gulf of Mexico . . . . . . . . . . . . . 8 - 10

Hydrex diver training programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Class Accepted underwater stern

tube seal repairs under warranty

Using our flexible mobdock

method to create

a dry underwater environment,

we have carried out

stern tube seal repairs and

replacements underwater

for some years now in cooperation

with top specialist


This technology brings drydock

conditions to the ship

rather than having to take the

ship to drydock, saving a

considerable amount of time

and money in doing so.

This class accepted method

is performed by our diving

teams under our warranty. It

can be used while the ship is

carrying out its usual cargo or

other commercial operations

in port.

Visit the special seal repair

section on our website for

more information and examples

of the many seal repairs

we have performed in recent





Table of contents

Underwater cleaning and inspection

of chord and spud can

connections of jack-up rig 4-5

Earlier this year we wrote about

a big repair operation that was

carried out on a crane barge in

Gabon. This magazine once more

focuses on the offshore industry and

offers you an overview of two of the

offshore inspection and cleaning

operations our divers have carried

out in the last couple of months.

One operation was carried out on

a jack-up rig stationed in Gabon

that needed to have the connections

between its chords and spud cans

cleaned and inspected while the unit

moved to another location. The other

operation involved the removal of all

fouling on two drilling vessels in the

Gulf of Mexico to increase their cargo


Besides the cleaning and inspection

work described in this magazine

Hydrex also offers a range of preventive

and protective maintenance services

that are highly effective and

save a great deal of time and money

in comparison with the costs incurred

during a breakdown for which

there has been no preparation. With

preventive engineering and scheduled

maintenance, work delays can be

eliminated or reduced significantly.

Best regards

Boud van Rompay

In-house developed ship hull cleaning

equipment used on drilling vessel

ISO 9001 certified

To receive a free copy, fax to:

Hydrex N.V. +32 3 213 53 21

or e-mail to

Underwater maintenance work

carried out on drilling vessels

in Gulf of Mexico 8-10

Hydrex diver training

programs 11



Underwater cleaning and

inspection of chord and spud

can connections of jack-up rig

Hydrex technician working on spud can of jack-up rig

When a jack-up rig located

in Gabon was scheduled to

move to another location, a Hydrex

team mobilized from the company’s

office in Port Gentil to perform

an underwater cleaning and full

inspection of the drilling platform’s

chord and spud can connections.

An underwater cleaning operation

facilitates any needed full-scale

inspection of an offshore unit, which

was an important factor for the owner

of this rig as he wanted to have nondestructive

testing (NDT) of the

connections between the chords and

the spud cans carried out. Because the

legs of this type of offshore unit are

embedded into the sea bottom while

the rig is stationed, testing can only be

performed when its legs are raised

during a mobilization.

There was a timeframe of only 3 days

available for the team to perform the

necessary operation before the rig

arrived at its new location and the legs

would be jacked down onto the sea

bed again. For this reason a Hydrex

supervisor went on board the rig prior

to the operation to discuss the scope of

the work and finalize the HAZOP.

This was done to make sure that both

the underwater cleaning and inspection

were perfectly geared to the

mobilization schedule of the platform

and that the safety of the team would

be guaranteed at all times.

Hydrex diver ready to be lowered into the water during offshore



Helicopter escape training during offshore course

Hydrex diver during underwater hull cleaning on offshore unit

All Hydrex diver-technicians have

completed offshore training

The team was brought on board the

rig in advance together with the

needed equipment. This enabled them

to initiate the operation as soon as

the retraction of the first leg started.

Both the underwater cleaning work

and the consequent inspections were

finished by the time the rig reached its

destination and no time was lost for

the customer.

All Hydrex diver-technicians are fully

certified and can be mobilized immediately

to service offshore related

units. This can save precious time for

customers in the case of an emergency

or tight deadline.

Raised leg of jack-up rig prior to operation

Jack-up rigs in Gabon


Worldwide network


of Service stations


Underwater maintenance work

carried out on drilling vessels

in Gulf of Mexico

Drilling vessel serviced by Hydrex in Gulf of Mexico

Recently Hydrex was asked to

carry out a full inspection and

remove all fouling from two drilling

vessels in the Gulf of Mexico to

reduce the weight and drag of the

vessels and increase their available

cargo capacity.

An inspection team and two cleaning

teams, each consisting of 7 team

members, were therefore mobilized

from the Hydrex offices. All Hydrex

offices are fully equipped and ready

to mobilize immediately to carry

out high quality and fast underwater

cleaning operations or any other maintenance

and repair work on offshore

Hydrex team during set-up of operation on drilling vessel


Underwater hull cleaning of drilling vessel

in Gulf of Mexico

Hydrex underwater cleaning team and equiment

units and ships located in the Gulf of

Mexico or any other location.

Dive support vessel with Hydrex equipment approaching drilling vessel

Hydrex had carried out repairs on

other offshore units belonging to the

same owner and he knew that the

company could offer the required

services without having to take the

vessels to drydock. The scope of work

consisted of a comprehensive UWILD

inspection of both drilling vessels,

an inspection of the weld seams in

particular, replacement of anodes

wherever needed, blanking all overboard

lines in order to enable inspection

from the inside and hull cleaning

the underwater parts of the units.

The Hydrex teams also assisted with

the removal of one of the vessels’

thrusters so that they could be overhauled.

While a class surveyor was monitoring

the team that was carrying out

the inspection required by the class,

an underwater cleaning team was

working simultaneously to make sure

that the operation would be finished

within the available timeframe. For

the same reason one of the teams was

transferred to the second vessel to

begin the second operation while the

other teams finished the underwater

cleaning work on the first unit.

Hydrex diver-technician getting ready for underwater hull cleaning


fouling from tubular pipes, bracings

and legs of offshore oil and gas

platforms, jetties, piles, intakes and

ship hulls. The triple head MC312

(Typhoon) machine is easily adaptable

to the shape of a ship or pontoon hull.

Its heads self-adjust to the contours of

the hull making complex areas far

easier to clean.

Hydrex diver cleaning drilling vessel in Gulf of Mexico

While assisting these two vessels,

the same customer asked Hydrex to

perform another operation on one

of its offshore platforms stationed

in Gabon for maintenance work.

Workers needed to access the platform

on a daily basis. Therefore the owner

wanted to have scaffolding installed

All operations were performed with

a new range of the Hydrex underwater

cleaning units which is designed

specifically for offshore operations

and can remove all types of fouling

from any type of offshore structure.

This offers owners big savings in

fuel when moving their unit from

one location to another and also

reduces drag and weight on the unit,

an especially important factor for the

owner of these two drilling vessels.

An all-embracing combination of

single, twin and triple head cleaning

machines was used. The twin head

MC212 unit is designed for cleaning

light, medium and heavy marine

Hydrex diver-technician installing scaffolding on offshore platform in Gabon

and welded to the platform’s legs

to provide a safe entrance for the

workmen. Thanks to the close proximity

of the Hydrex office in Port

Gentil, we were able to install the

scaffolding just days after the request

came in.

Hydrex diver-technician welding scaffolding on offshore platform in Gabon


Hydrex diver training programs

One of the reasons Hydrex can

offer its customers the high

quality of service they deserve is

the stringent training all divers

go through, whether they work for

the Hydrex main office in Antwerp

or for one of the other offices.

Besides being required to have

official international commercial

diver certificates and taking high

standard external courses, including

offshore courses, they also receive

comprehensive in-house training.

Tank training during offshore course

Theoretical part of offshore course

This consists of both theoretical classes

in the course room and practical

drills on the Hydrex premises. There

they have access to a wide range of

underwater tools and various other

equipment, including three dive tanks

In-house practicing of wet welding

in which to practise underwater welding

and other repair work.

In addition to these classes, new

divers also get the opportunity to

assist experienced Hydrex diver-technicians

during operations. The training

enables them to become experienced

divers and technicians themselves

and to take advantage of the

technical knowhow and practical

knowledge Hydrex has accumulated

over the last 35 years. When their training

is completed, Hydrex divers are

skilled to perform a wide range of

operations. They can carry out both

simple and complex jobs even in

harsh circumstances and achieve this

uniformly without unnecessary loss of

time or quality.

Diver ready to enter one of the training tanks at the Hydrex headquarters in Antwerp


Keeping ships in business

Hydrex underwater technology

and services provide

high quality solutions

to the repair and replacement

problems encountered

by ships and offshore vessels.

We deliver a complete line of

services that may reduce or

avoid off-hire time entirely.

From major projects to simple

inspections, Hydrex has the

worldwide facilities and capability

to meet your demands.

Drydocking is not necessary

so time, trouble and expense

are saved by doing work

in-situ. Hydrex services cover

highly technical major repairs

or replacements of a ship’s

external underwater equipment

such as thrusters, propellers,

rudders, stern tube

seals and damaged or corroded


Hydrex Headquarters – Antwerp Phone: +32 3 213 53 00 (24/7) E-mail:

Fax: +32 3 213 53 21

Hydrex US - Tampa Phone: +1 727 443 3900 (24/7) E-mail:

Fax: +1 727 443 3990

Hydrex Spain – Algeciras Phone: +34 956 675 049 (24/7) E-mail:

Fax: +34 956 921 914

Hydrex India - Mumbai Phone: +91 222 2046 988 (24/7) E-mail:

Fax: +91 222 2046 988

Hydrex India - Vishakhapatnam Phone: +91 891 2711 863 (24/7) E-mail:

Fax: +91 891 2711 863

Hydrex West Africa – Port Gentil Phone: +241 04 16 49 48 (24/7) E-mail:


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