A Quarterly Magazine from ABS
Fall 2011
Computer Modeling Rebuilds
an Ancient Ship
I
n this photo, taken in the Visualization Lab at Texas A&M University, computer science student
Audrey Wells views part of a three-dimensional model she created of a Portuguese merchant
ship named Nossa Senhora dos Martires, which was shipwrecked offshore Portugal in 1606.
Far more than a mere visualization, the model reproduces the vessel in its entirety, including full
scantlings, internal construction details, outfitting and the sail plan, such that seakeeping, stability
and other analyses can be performed. This remarkable achievement resulted from a unique interdepartmental effort led by Dr. Filipe Castro of Texas A&M’s Nautical Archaeology Program, which
married computer science, archaeology, historical research and marine engineering to resurrect
the ancient ship from scant physical remains – just 11 percent of the hull survived – and long-lost
diaries and technical documents.
A Quarterly Magazine from ABS
Fall 2011
COVER:
Reducing the resistance of the underwater body of ships of all types is the
focus of renewed research as the industry seeks to reduce both the cost of fuel
consumed and the volume of potentially harmful emissions released into the
atmosphere. In this issue, Surveyor looks at the concept of using an air mass
to achieve this goal and talks to leading marine paint companies about their
efforts to develop the latest generation of effective anti-fouling coatings.
FEATURES:
the Era of Energy Accounting
2 Entering
The latest evolution of MARPOL Annex VI requires that companies record,
analyze and improve the way they and their ships use energy.
6
Scrubbing to Satisfy SOx Specs
Machinery helps ships meet strict sulfur regulations.
10
Airship of the Sea
The AirMax hopes to boost ship efficiency by replacing part of its hull
surface with air.
16
Meeting the Post-Tin Challenge
Anti-foulings move forward as tin fades into history.
24
Poison Paints & Magic Metals
Snapshots from 3,000 years of fighting fouling.
27
The Cyber-Resurrection of Our Lady of the Martyrs
Nautical archaeology, engineering and computer science combine to rebuild
a ship type not seen in centuries.
Published by ABS.
ABS Plaza
16855 Northchase Drive
Houston, TX 77060 USA
Tel: 1-281-877-5800
32
Viewpoint: Bringing on Tomorrow
Ulf G. Ryder, CEO of Stena Bulk, on innovation and people.
Fax: 1-281-877-5803
Email: abs-worldhq@eagle.org
Web: www.eagle.org
For permission to reproduce
any portion of this magazine,
send a written request to:
ABSSurveyor@eagle.org
Joe Evangelista, Editor
Christopher Reeves, Graphic Designer
Sharon Tamplain, Graphic Designer
Sherrie Anderson, Production Manager
Photo Credits:
Jean Gould, Vice President
Cover, 22: Sea Sub Systems; IFC, 27-31: Institute of Nautical Archaeology and Dr. Filipe Castro; 2 (bottom), 3 (top) 4
(top): Maran Tankers Management; 2, 3, 4, 16, 22, 24, 26: ABS archive; 4 CMM; 6, 8: Wärtsilä; 7: MAN B&W; 9: SOCP;
Copyright © 2011.
10-15, 32 Stena Bulk; 14 (bottom), 23 (bottom), IBC: Joe Evangelista; 17: Jotun; 18: PPG; 19: Portline; 20, 21: Hempel;
25: Discover Copper.
The opinions and conclusions contained in this publication are solely those of the individuals quoted and do not reflect, in any way,
the position of ABS with regard to the subjects raised. Although every effort is made to verify that the information contained in this
publication is factually correct, ABS accepts no liability for any inaccuracies that may occur nor for the consequences of any action
that may be taken by parties relying on the information and opinions contained herein.
Fall 2011 • Surveyor | 1
Entering the Era of Energy Accounting
The latest evolution of MARPOL Annex VI requires that companies record, analyze
and improve the way they and their ships use energy.
ttempting to improve the energy
efficiency of the maritime industry,
a new regulation mandates that ship
operators establish an accounting system for
the energy consumed by their companies
and by the ships they operate.
A
The 62nd session of the Marine
Environmental Protection Committee
(MEPC) of the International Maritime
Organization (IMO) concluded this past
July with a further evolution of Annex
VI (regulations for the prevention of air
pollution from ships) of the International
Convention for the Prevention of Pollution
from Ships (MARPOL Convention). Part
of that evolution was the establishment of
Annex VI Chapter 4 (regulations on energy
efficiency for ships) – a brand-new set of
measures that mandates application of the
Energy Efficiency Design Index (EEDI) to
new ships and a program named the Ship
Energy Efficiency Management Plan
(SEEMP) for all ships.
Johnny Eliasson,
Manager,
Environmental
Solutions Group,
As a concept, SEEMP has been around for
several years. In the report issued at the
conclusion of its 59th session in 2009, the
ABS
The MARAN PENELOPE is one of the first vessels in MTM’s
tanker fleet to be subject to a Ship Energy Efficiency
Management Plan (SEEMP).
2 | Surveyor • Fall 2011
MEPC provided guidance for developing
such a program. The purpose of a SEEMP,
the report says, is “to establish a mechanism
for a company and/or a ship to improve
the energy efficiency of a ship’s operation.
Preferably, the ship-specific SEEMP is linked
to a broader corporate energy management
policy for the company that owns, operates
or controls the ship…”
The guidance identifies the four key steps
to establishing an effective SEEMP as
planning, implementation, monitoring, and
self-evaluation and improvement (Item 2.4).
In explaining the process, it stresses the
importance of Phase I, the assessment stage,
where the operator analyzes the ship’s current
state of energy usage, identifies the energysaving measures already undertaken and
determines how effective these measures have
been. Then the process identifies what new
measures can be adopted to further improve
the energy efficiency of the ship (Item 3.3)
and includes them in the SEEMP.
In a stepwise progression, an operator first
develops an energy management system
(EnMS) based on an environmental standard
like ISO 14000 or broader energy-management
standards like BS EN16001:2009 and the
recently arrived ISO 50001. Under the EnMS,
a company develops a Company Energy
Efficiency Management Plan (CEEMP),
addressing energy consumed by the enterprise
overall, and then likewise produces an energy
plan for each vessel in its fleet, the SEEMP,
which is like a ship-specific catalog of energy
efficiency activities established by the operator
and practiced by the crew on board.
“In simplest terms, the SEEMP is a document
stating what a particular ship is doing to reduce
energy consumption on board, such as its
antifouling maintenance program, its propeller
policy, its machinery and operational practices
– it covers quite a lot of ground,” says Johnny
Eliasson, Manager of the Environmental
Solutions Group at ABS. “For example, one
energy reduction measure currently being
talked about is a ship’s speed policy, where,
for example, instead of steaming full ahead,
arriving early and waiting at anchorage to
load, the ship communicates with the parties
involved and reduces voyage speed so as to
arrive just on time.”
fleet vessel levels,” says Stavros Hatzigrigoris,
Managing Director of MTM. “The combined
plan provides procedures and measures to
improve the energy efficiency on board
the managed ships, guidance and standard
practices on best energy management under
the various operational modes of the ship,
and gives information for raising awareness
on energy efficiency matters,” he says.
“MTM expects SEEMP implementation to
assist us in establishing a structured mechanism
to assess and improve the energy efficiency
of ship operations in accordance with a
systematic, well-defined and documented
methodology,” adds MTM’s HSQE Manager
Sokratis Dimakopoulos. “You can manage
well only what you can measure well.”
The second major shipping company in
Greece to undertake the SEEMP process,
Piraeus-based Consolidated Marine
Management (CMM), recently completed
its assessments under Phase I and, as this
issue went to press, was planning the
workshop where, collaborating with ABS,
its SEEMP would take shape.
Eliasson and Luiz Motta, ABS Technology
and Business Development Director, Eastern
Europe and Middle East Region, led the
cooperative effort through which Greece’s
largest tanker operator, Maran Tankers
Management Inc. (MTM) developed its
CEEMP and SEEMP programs. In May this
year MTM became the maritime industry’s
first major operator to develop and complete a
CEEMP and SEEMP in cooperation with ABS.
Something Old, Something New
“We developed the combined CEEMP/SEEMP
with the aim of continually improving energy
efficiency performance at the company and
“By maintaining an EnMS you formalize,
make more systematic and apply, in the
best managed way, what you used to do
Luiz Motta,
Director, Technology and Business
Development, Eastern Europe
and Middle East Region,
ABS
Ship operators have been trying to improve
the efficiency of the vessels ever since ships
traded sails for engines; so, essentially, what
the SEEMP asks them to do is nothing new.
Many operators will find that, to a certain
extent, the SEEMP merely formalizes practices
and programs they have followed for years,
though perhaps not in a systematic way.
Fall 2011 • Surveyor | 3
in practice but not within a management
system framework,” says Kostas Vlachos,
Chief Operating Officer at CMM. “The
benefit of a management system, a quality
management system or an energy management
system, is that it gives you tools for planning,
implementation, monitoring, review and
feedback, which, in turn, enable you to developp
a program of continuous improvement.”
Stavros Hatzigrigoris,
Managing Director,
MTM
Kostas Vlachos,
Chief Operating Officer,
To what extent the SEEMP introduces new
practices depends on the level and status
of the existing procedures a company has
in place to monitor and manage energy
efficiency and fuel consumption, says
Hatzigrigoris. “For a proactive and wellorganized operator, it is not expected that
the SEEMP will require the introduction of
many new additional procedures,” he says.
“However, the SEEMP would definitely assist
even well-organized operators in establishing
and better documenting their energy-related
management tools, and in benchmarking,
internally and externally, the efficiency of the
implementation of the related procedures,” he
says. “MTM, for example, already incorporates
fuel saving measures and efficiency technology
across our new building specifications and
ship operations. That said, having in place the
CEEMP and SEEMP allows these measures
to be documented and monitored for further
improvement. It also allows us to be proactive
in satisfying upcoming regulations, customer
requirements and society’s expectations.”
MTM’s program is linked to its EnMS and the
relevant Environmental Program on Energy
Efficiency that it established, implements
and maintains in accordance with ISO
14001. CMM based its EnMS on the BS
EN16001:2009 standard. Whatever base
document is used, the most important aspect of
the process is that the SEEMP is developed by
the company itself, says Eliasson. Ultimately,
the CEEMP and SEEMP must be individualist
products that reflect the unique characteristics
and experiences of a company and its ships.
“A consultant can certainly help a company
write its documents, but, for a SEEMP to be
effective, it must be developed by the vessel
operators themselves,” says Eliasson. “The
operators know the ships better than anyone
else, they know exactly what the company
does, and they know from experience what
could work and what can’t work for them. An
outsider who comes along with a pre-prepared,
fill-in-the-blanks SEEMP is not going to help
the client that much, because the resulting
document will not be a ‘natural product’
that grew out of the company’s experience,
reflecting procedures and practices that the
people already understand,” Eliasson explains.
“Instead, it will be more like a foreign object
to which the staff will have to adapt. That’s
why all we offer to do is facilitate the process of
SEEMP document development in accordance
with the IMO formats,” he says.
“In the case of MTM, for example, we met
with them, cataloged the energy efficiency
measures they had already taken, assessed
those measures and delivered a report for
them to study,” says Eliasson. “We then
organized a workshop in which we reviewed
their activities one by one and suggested other
measures they could undertake. Some of these
they considered immediately, some would
be considered in the future, and some they
believed were not applicable,” he says. “They
then made their decisions as to the SEEMP
content, after which we discussed how the
CMM
The ABS-classed HELLAS SERENITY is one of the first
gas carriers in the CMM fleet that will be subject to
the company’s SEEMP.
4 | Surveyor • Fall 2011
MANAGERIAL
TECHNICAL
items would be implemented,
who would be responsible,
how they would be measured
and what would be the goals.
It’s a straightforward approach
that appealed to MTM,
to CMM and the other
companies that are following
their examples.”
PLAN:
• Policy/goals/targets
• Resources
PLAN:
• Energy data
management
• Assessments
A Familiar Challenge
ACT:
• Management review
DO:
• Training
• Communication
• Control equipment
systems & processes
DO:
• Energy Purchasing
• Design
• Projects
• Verification
CHECK:
• Corrective/
preventative action
• Internal audits
Philosophically, the SEEMP
process is rooted in the ‘Plan,
Do, Check, Act’ methodology
already familiar to the maritime industry through its implementation of
Safety Management Systems (SMS). While
there are many similarities there are also
important differences, particularly for tankship
operators, whose plans must comply with
IMO’s SEEMP Guidelines, the Intertanko
Guide for Tanker Energy Efficiency Management
Plans and the OCIMF Guide for Energy
Efficiency and Fuel Management.
“The SEEMP is an individual manual/
plan, however, it is considered as part of our
SMS and it will be subject to our standard
management review of quarterly procedures
with the aim of continual improvement,”
says Dimakopoulos. The company believes
the SEEMP will assist in accomplishing
a number of other objectives as well,
including establishing a better energy
baseline, developing its energy-related
targets and measuring, in an accurate way, its
achievements in those areas. It is also expected
to enhance the energy-related training of the
company’s seagoing personnel. Importantly, it
will help communicate all that to the world
outside the company. “SEEMP should also
provide objective evidence to third parties, i.e.,
charterers, on the efforts that each company is
making in this area,” Dimakopoulos says.
Like any self-improvement effort, energy
management programs are neither formed nor
followed for free, but its early adopters appear
to view the investment required by the SEEMP
mandate with a measure of optimism.
“Certainly, operators will invest money in
developing, following and maintaining a
CEEMP for the company and a SEEMP for
each ship, but they will also receive dividends
– consider that savings in fuel consumption
may amount to 6 to 7 percent through
operational measures alone. At the end of the
day, when you compare all the costs against
CHECK:
• Monitoring
• Measurement
ACT:
• System performance
all the savings and benefits, I believe that
the balance will be in favor of these energy
management programs,” says Vlachos.
“The SEEMP will organize energy efficiency
matters in a much better way than before,
while assisting the seagoing personnel in the
implementation of the daily routines on board,”
Hatzigrigoris concludes. “It is expected that
the CEEMP and SEEMP will bring real added
benefit to the company; however, it might
take some time for this benefit to be measured
clearly and objectively.” ❖
Competitiveness Through Conservation:
CMM on SEEMP
e are developing our ship energy efficiency plans in order to promote
energy conservation on board the vessels, to improve the performance
of our vessels and, of course, to make our vessels more competitive – but not
only more competitive through cost savings,” says Kostas Vlachos, COO of
Piraeus, Greece-based Consolidated Marine Management (CMM).
“W
“I believe an energy management program has financial, economic and
environmental benefits. By establishing an energy management system CMM,
for example, will have more than the benefit of better fuel consumption,
because our vessels will present themselves to our customers and to the
general public as environmentally advanced, which, at the end of the day,
will make them more attractive to reputable charterers, such as the members
of the Oil Companies International Marine Forum (OCIMF).
“Because energy management is not only about cutting costs, but also
about doing something proactive for the environment, it will become an
increasingly important factor as time goes on. I believe that, in the future,
the stance that shipping companies take towards energy efficiency will
create, to their clients, different levels or tiers of vessel operators.” ◆
Fall 2011 • Surveyor | 5
Scrubbing to Satisfy SOx Specs
Machinery helps ships meet strict sulfur regulations.
A
s of August 2012, all merchant ships
coming within 200 nautical miles of
the coasts of North America and
Hawaii will have to comply with steeply
increased air pollution controls. The new
standard, which reduces by 98 percent the
permissible sulfur content of marine fuels
used in the protected zone (among other
limits), is part of an expanding inventory of
regional protections established under the
international regulation known as MARPOL
Annex VI.
Officially titled Regulations for the Prevention
of Air Pollution from Ships, Annex VI of the
International Convention for the Prevention
of Pollution from Ships (MARPOL) was
adopted by the IMO in 1997 and entered into
force in May 2005. The first international
instrument specific to air pollution from ships,
it provided control of pollutants such as:
ozone-depleting substances from refrigeration
and firefighting equipment (Regulation 12);
nitrogen oxide (NOx) in exhaust emissions
(Regulation 13); sulfur oxide (SOx) exhaust
North America ECA
emissions controlled via regulation of fuel
sulfur content (Regulation 14); volatile
organic compounds released from cargo oil
tanks (Regulation 15); and emissions from
shipboard incinerators (Regulation 16).
Regarding sulfur in marine fuels, the
regulation provided more a maintenance of
the status quo than a new control, limiting
sulfur content to 4.5 percent or 45,000 parts
per million. As a reference, the standard
applied to road vehicles in the US is 15 parts
per million.
Still, Annex VI did offer MARPOL
signatories a way to tackle local air pollution
issues under Appendix III, which provides
a procedure for recognizing specific sections
of waterway or coastline as sulfur emissions
control areas (SECAs), regions deemed so
environmentally- sensitive as to require
immediate and severe reduction of SOx
emissions. A SECA candidate would be a
region known to have suffered deforestation,
crop destruction or other damage due to acid
rain. Soon after Annex VI entered into force,
the Baltic Sea was declared the world’s first
SECA in 2005, followed by the North Sea
(including the English Channel) in 2006.
North Sea/Baltic ECA
Caribbean ECA
6 | Surveyor • Fall 2011
When Annex VI was revised in 2008, one of
its changes expanded the concept of the SECA
to the more general emissions control area
(ECA), in order to allow regional protection
based on emissions of particulate matter and
NOx as well as SOx. Within a year, the US and
Canada submitted a joint application to IMO
that, in 2010, resulted in creation of the North
America ECA, the third and largest ECA to
date, which will extend 200 nautical miles off
the coast of United States and Canada and
likewise off the eight main Hawaiian islands
and the French island territories of Saint-Pierre
and Miquelon.
Agitation for other ECAs soon began and, in
July 2011, IMO approved the waters off the
coasts of Puerto Rico and the US Virgin Islands
as another ECA (the United States Caribbean
Sea ECA), expected to enter into force on
1 January 2013 and take effect 12 months
later. Japan has submitted an application for
an ECA to embrace its shores, and movements
are reported to have begun in Singapore and
Australia to obtain sulfur protection for their
coastlines as well. It is expected that more
ECAs will be declared as other coastal nations
get their arguments together.
Besides changing the ECA rules, the 2008
Annex VI revisions also included a timetable
for global reduction in the allowed sulfur
content of marine bunker fuel. Today’s levels
of 4.5 percent will drop to 3.5 percent in
2012, then to 0.5 percent by either 2020 or
2025, depending on the outcome of a refinery
industry study that is expected to be completed
d
by 2018. At the same time, the sulfur limit
in ECAs would be reduced to 0.1 percent by
2015 (it dropped to 1 percent in 2010 as part
of this process).
Installing an ‘Equalizer’
Annex VI sulfur caps apply to all ships,
regardless of age or keel-laying, but do not
require that operators shift to expensive
low-sulfur fuels such as marine gas-oil (MGO).
Since the regulation covers only sulfur content,,
not the type of fuel, operators are free to
use anything from heavy fuel oil (HFO) to
light distillates as long as limits are met.
In addition, under Regulation 4, ships are
allowed to meet emissions objectives through
alternative means, which, at the moment,
means installation of an exhaust gas cleaning
system or ‘scrubber’. A sufficiently effective
scrubber system would allow operators to meet
low-sulfur requirements while burning today’s
high-sulfur heavy fuel oils.
Last year, MAN Diesel & Turbo signed a
cooperation agreement with Hamburg,
Germany-based Couple Systems, whose
DryEGCS dry scrubber debuted on
a German vessel in 2009.
Scrubbers, used for decades in shoreside facilities such as power plants, process exhaust gases
to remove sulfur compounds and trap them
as liquid or solid waste. Most current scrubbing systems use a ‘wet’ method, running the
exhaust gas through either saltwater or freshwater plus an alkaline additive such as sodium
hydroxide (caustic soda), which neutralizes and
traps the acidic sulfur compounds. Dry scrubbers remove SOx compounds in a waterless
reactor vessel filled with a granulated alkali
such as calcium hydroxide.
Engine manufacturers have entered the scrubbing market to offer their customers integrated
scrubbing solutions. Last year, MAN Diesel &
Turbo signed a cooperation agreement with
Hamburg, Germany-based Couple Systems,
whose DryEGCS dry scrubber debuted on a
German vessel in 2009. Their system uses a
calcium hydroxide (CaOH) reagent to catch
the SOx gases and produce a recyclable calcium
sulfate (gypsum) waste.
Back in 2005, Finnish engine manufacturer
Wärtsilä teamed up with Helsinki-based Metso
Corporation to develop a marine scrubber.
Each has long experience in land-based
scrubber applications and, working with other
companies in the Finnish maritime cluster,
soon had a marine unit ready for trial. A
prototype of the Wärtsilä SOx Scrubber was
tested aboard a Finnish tanker from 2008 to
2010. The trial concluded very successfully,
according to Wärtsilä, and the first commercial
order was soon received. The unit is due for
delivery this year. Relying on the natural
Fall 2011 • Surveyor | 7
Freshwater
Scrubber Layout
5
1. SOx Scrubber Unit
2. Alkali Feed Module
1
3. Bleed-off Treatment
Module
4. Effluent Monitoring
Module
5. CEMS (Continuous
Emissions Monitoring
System)
6
Freshwater
~0.1 m3/MWh
3
~25 m /MWh
6. Scrubbing Water Pump
Module
Bleed-off
~0.1 m3/MWh
7. Sea Water Pump
3
8. Heat Exchanger
9. Buffer Tank
10. Alkali Storage Tank
11. Sludge Tank
Sludge
~0.1-0.4 kg/MWh
4
8
10
11
9
2
7
Effluent
~0.1 m3/MWh
alkalinity of seawater to neutralize and capture
SOx gases, the Wärtsilä SOx Scrubber is a
freshwater system.
Britt-Mari Kullas-Nyman,
General Manager,
Air & Energy Solutions,
Wärtsilä
“The waters around us, especially the Baltic
Sea, are of low alkalinity; a seawater scrubber
would require a very large amount of that
water to neutralize all the sulfur dioxide in the
exhaust gas,” says Britt-Mari Kullas-Nyman,
General Manager, Air & Energy Solutions for
Wärtsilä. “Since we expected to have many
customers with ships sailing in these particular
areas, we decided to develop a freshwater
scrubber, where we would control the pH with
caustic soda and, so, could be sure that all the
sulfur dioxide is neutralized. In addition, we
saw the possibility of having a closed-loop
system, which lets us clean the exhaust and
remove the effluents from the scrubber system
to extremely good levels,” she explains.
The Wärtsilä system uses sodium hydroxide
(NaOH), which increases the pH of the water
to the point where the water itself reacts with
the SOx to form sulfates. The particulates, oil
and other materials trapped in the wastewater
are removed in an emulsion-breaking and
flotation-type cleaning system and the cleaned
water, containing the sulfates, is released to the
sea. Since seawater already contains sulfates,
and the pH of the scrubber’s wastewater is
close to the average for the natural environment, the discharge meets IMO’s washwater
guidelines for environmental safety.
Challenges and Promise
There is, however, one waste product of
wet scrubbing that raises questions from its
potential users. The soot, particles, oil and
heavy metals that are removed from the
8 | Surveyor • Fall 2011
exhaust gas stream potentially end
up in the sludge. Tests of the sludge
from an open loop seawater scrubber
revealed that it consisted mainly of
silt and small amounts of gypsum, with
only minute amounts of soot that were
not found to be hazardous kind, yet
best kept apart from the engine room
sludge. However, different processes
can yield different scrubber sludge
types, and some can be similar enough
to engine room sludge that the two
can be disposed of together onshore –
and therein lies the concern. Although
a scrubber produces far lower volumes
of sludge than an engine room (the
Wärtsilä closed loop system, for
example, yields less than 10 percent
of a normal engine room’s output,
says Kullas-Nyman), it shares equally in
the disposal challenge.
Availability of shoreside sludge reception is a
problem as old as the MARPOL Convention
itself. Although each of the 150 nations
that signed the MARPOL contract agreed
to provide port facilities to offload ships’
engine room sludge, even after three decades
many have failed to do so. Many years ago,
tanker owners group Intertanko began a
well-documented battle to enforce this basic
MARPOL obligation and, while there has
been some improvement to the situation over
time, it remains a serious enough problem
to require an ongoing international effort
under IMO’s Action Plan on Tackling the
Inadequacy of Port Reception Facilities,
which was developed in 2010 by the SubCommittee on Flag State Implementation
of the MEPC.
For this reason, the logistics of waste disposal
is showing up as a client question that scrubber
sellers have to address. Wärtsilä ascertained
that its first client ship will have access to good
sludge reception in Finland and Sweden, and
the company is assessing coverage in other
regions on a case-by-case basis for customers
with upcoming orders.
Existing vessels looking to retrofit a scrubber
may also find a challenge in trying to squeeze
it into their already very efficiently used
machinery spaces. Scrubber systems are not
small; a 10-MW Wärtsilä SOx Scrubber, for
example, measures 3.5 m wide and 6 m high.
A typical scrubber location is the exhaust gas
funnel, when that isn’t already crowded with
antipollution or energy efficiency equipment.
The issue may be resolved more easily on
tankers and bulk carriers than on, say, cruise
ferries, some of which have up to 100 MW
of installed power and barely enough room
for a coffee maker in their non-revenueproducing spaces.
Then there is the issue of cost. “A scrubber
system isn’t cheap, and for some clients
represents a significant cost item,” says
Kullas-Nyman. “That said, the people we
have spoken with tend to see the installation
as an investment, paying back costs over
time through savings on marine gas-oil,
which, in the future, will probably be much
more expensive than heavy fuel oil. So,
against the challenge of getting a scrubber
system on board, there is the economic
benefit you get from using it.”
At least, scrubbers aren’t technically
challenging, she says, and should not add
significantly to the burden on the crew.
“Scrubbers are fairly simple systems: pumps
move the water through the scrubber, which
has no moving parts; then there is the water
cleaning unit, which, perhaps, is the most
sophisticated part of the system; and then
there are heat exchangers and other basic
components,” she says. “When the crew get
used to having a scrubber on board, they will
find it is not much more complicated than a
boiler system.” ❖
Scrubbers Guide Helps Operators Decide
I
n April this year, the Washington,
DC-based Ship Operations Cooperative
Program (SOCP) announced completion
of a study on exhaust gas cleaning systems
or scrubbers. Produced for operators of ships
that will be sailing in emission control areas
(ECAs), the study was designed to aid in
the decision of whether to switch to lowsulfur fuels when within an ECA or to use
a scrubber system and continue burning
high-sulfur fuel.
Developed by Seattle-based naval architecture firm Glosten and Associates in
cooperation with the SOCP, the guide helps
operators understand emissions requirements, calculate potential costs and assess
the technical and operational challenges
of various scrubber technologies. It also
includes a large appendix providing technical
details on various systems supplied by their
manufacturers.
“My advice to shipowners is to read the
executive summary and the discussion in the
back of the guide and see if it makes sense
for your ship. If so, inside there are sections
summarizing the pros and cons for the
different technologies,” says Susan Hayman,
Vice President at Seattle-based Foss Maritime
Company, who served as SOCP project
manager on the Scrubber Guide effort.
“One of the interesting points in the study
for me was the potential impact of scrubbers
on crew size,” says Hayman. “We figured it
would probably need a ‘50-percent engineer’
– that is, if you have sufficient time and
staff within your current structure, you could
possibly absorb the maintenance and upkeep.
Our conclusion was that most ships probably
do not have that capacity and might have to
add an engineer. Of course, owners will have
to assess each ship to see if another person is
really needed.”
The SOCP is a public-private cooperative
in which members pool resources to work on
industry issues, and is open to any US-based
vessel operators and maritime organizations.
“With the support of the US Maritime
Administration (MARAD), industry, labor,
and Government work together in the SOCP
to address common challenges and identify
new solutions for improvements in US ship
operations,” says Glen Paine, Executive
Director of the Maryland-based Maritime
Institute of Technology and Graduate Studies
and President of the SOCP. “This structure
allows us to leverage funds where say one
company doesn’t have the funds to get a
project done. It is a non-partisan cooperative
and the members all share the results of the
work. If it’s for the industry as a whole, we
will tackle it.”
The scrubbers guide was developed with the
financial support of MARAD and the SOCP.
Although SOCP is a group created by and for
the US maritime sector, the group produced
its report for the benefit of the entire maritime
industry. The report can be downloaded at no
cost from the SOCP website at www.socp.us.
SOCP members will be required to log in and
non-members will need to email a request. ◆
Susan Hayman,
Vice President,
Foss Maritime Company
Glen Paine,
Executive Director,
Maritime Institute of Technology
and Graduate Studies,
President, SOCP
Fall 2011 • Surveyor | 9
Airship of the Sea
A visualization of the AirMax
concept showing an early
version of the air cavity
A unique ship prototype replaces part of its hull surface with air, expecting
to boost propulsive efficiency by more than 20 percent.
design. The prototype design
now being tested is nearly
rectangular and has a beam
down the centerline for
docking strength plus one to
each side of it for stability.
10 | Surveyor • Fall 2011
ith fuel prices hitting all-time highs
and marine diesels operating near
their theoretical peak efficiencies, the
maritime industry has been busily combing
through its technological attic, looking for old
ideas on lowering a ship’s energy consumption
that merit dusting off for another try. Now,
after seven years of research and development
by Gothenburg, Sweden-based shipowner
Stena AB, one old idea may be poised to return
from the engineering fringe in grand style.
As expressed in a new hull design named the
Stena AirMax, the concept of air cavity drag
reduction may be able to bring the bulk fleet
fuel savings of over 20 percent and, ultimately,
offer revolutionary new alternatives to ship
designers worldwide.
chamber and, effectively, ‘replace’ a portion of
the hull’s wetted surface (the area in contact
with water). This would lower the resistance or
drag that impedes the ship’s progress through
the water and, thereby, decrease the energy
needed to propel the vessel forward.
Air cavity drag reduction calls for an open
chamber to be built into the flat part of a ship’s
bottom. Shaped somewhat like an inverted
bathtub, this chamber is filled with pressurized
air when the ship is in the water. The idea
is that the air will keep the water out of the
One early investigation into air cavity
drag reduction, conducted in 1949 by the
Gothenburg-based SSPA ship research
institute, revealed some major problems with
applying the concept to large ships. “The
cushion of air considerably impairs stability,
W
Using air to reduce hull resistance is a
thought that has intrigued engineers and
naval architects since the mid 19th Century.
Generally known as air lubrication, the
concept comes in two basic forms: pump a
layer of air or bubbles between the ship and the
water, or make an indentation (air cavity) in
the bottom to hold a cushion of air in place.
Old Idea, New Foundations
and this fact alone might weigh decisively
against the whole device,” the researchers
wrote, reporting its main difficulty to be
“extreme sensitivity to changes of trim.”
They theorized the problem could be
improved by doing things to make the
bottom wider – for example, adding large
side keels – but noted that such measures
would considerably increase hull resistance.
“From the results of these experiments, it
may be said that air lubrication appears to
afford a considerable reduction in frictional
resistance,” they wrote, but concluded
that “many practical difficulties arise in
the provision and maintenance of the air
film and, for this reason, the idea may be
considered as generally impracticable.”
SSPA has been working closely with Stena
since the start of the AirMax project. One
reason why the AirMax team may succeed
where all earlier efforts failed is that they
have a better starting point than their
forbears: the proven, wide-body hullform
used for over a decade by the company’s
family of ‘Max’ tankships.
Back in 1999, Stena introduced the V-Max,
a shallow-draft supertanker that carries the
volume of two suezmax tankers (roughly 2
million barrels of oil, the typical capacity
of a VLCC), on the draft of one. At 320 m
long x 70 m wide, the V-Max realized some
of the most extreme length-to-beam ratios
in the merchant fleet. The key to giving
such a wide-bodied vessel good seakeeping
and performance was developing a twinskeg, twin-screw stern. The brainchild
of former Stena Technical Director Stig
Bystedt, the V-Max sprang from research
and development work done at Uddevalla
Shipyard, once a shining star of Swedish
shipbuilding. Head of design when the yard
Former Stena Technical
Director Stig Bystedt
(standing), working with
Orvar Toreskog on the
V-Max design.
Fall 2011 • Surveyor | 11
Dan Sten Olsson,
Ulf Ryder,
Managing Director
CEO,
and CEO,
Stena Bulk
Stena AB
closed in 1985, Bystedt and his staff joined
Stena to spearhead some of the company’s
most successful R&D efforts. During the past
12 years the Max concept has been applied
across a tanker family, including on
a product tanker designated ‘P-Max’
that became the vehicle for AirMax
development.
In 2004, Bystedt, now advisor to
Stena’s Technical Division (Stena
Teknik), proposed using an air cushion
to cut fuel costs. The idea grabbed the
imagination of shipowner Dan Sten
Olsson, who immediately committed
SEK 50 million (about $8 million) to
AirMax research. Design development,
model basin testing and analyses took
place in phases over the next five years,
during which the P-Max hull was
chosen as project platform and modified
to accommodate an air cavity.
Henrik Nordhammar,
Head of AirMax Project,
Stena Teknik
“The idea at the start was to benchmark
the air cavity effect to a known vessel,”
says Henrik Nordhammar, a naval architect
with Stena Teknik and head of the AirMax
project. “The experiment isn’t merely about
showing that an air cavity can bring energy
savings, but about measuring those savings
against a normal vessel that is best in its class
– otherwise, the terms ‘energy savings’ and
‘hull resistance reduction’ would not be very
meaningful,” he explains.
The first challenge facing Stena’s designers
was to make the modified P-Max lines as
good as possible, to give the project the
best possible starting point. Ultimately,
12 | Surveyor • Fall 2011
they produced a version of the P-Max hull,
with the same length, beam and draft, that
is almost as efficient as the original – a few
percent off in ballast condition and less
than five percent overall in terms of hull
resistance.
The principal modifications, made at the
bow and stern, were designed to give the
hull the most extensive flat bottom possible,
thus maximizing the opportunity for wetted
surface reduction. Working closely with
researchers at SSPA, the Stena team tested
a variety of cavity shapes, finally choosing
a nearly-rectangular design that is almost
half as long as the ship bottom and divided
by three longitudinal beams: one down the
centerline for docking strength and one to
each side of it for stability reasons.
One critical key to making it all work
together is found up front, in a wide, flat
bulbous bow that looks somewhat like
the skull of a hammerhead shark. Where
traditional bulbous bows are made to divide
the water so that it passes around the vessel’s
hull, Stena’s innovation makes the water flow
under the hull and over the air cavity. It also
allows the bottom to go flat and wide at the
earliest possible point on the hull. The bow
has earned Stena a patent for ‘a hullform that
improves the performance of an air cavity.’
The project hit a wall in 2009, when it
was determined that AirMax development
needed more than what traditional
experimental methods could provide. The
problem stemmed from the fact that ship
model testing had been created for use
with water, not air – an issue that had been
uncovered during the SSPA investigations
of 1949. Those researchers reported that the
presence of air interferes with the standard
scaling-up calculations employed in model
testing and results in inaccurate assessment
of hull resistance; they also noted that this
problem had skewed the earlier research by
de Laval and Taylor.
For Stena Teknik, this meant that their
standard 1:44 scale model basin tests could
not give a good enough answer on how a
full-size AirMax should perform. In response,
the investigators made a bold decision to
go forward, doing something never before
attempted: they would build a much larger,
self-propelled scale model and test it in the
natural environment.
Unique Model uses Nature
as Laboratory
The AirMax prototype was designed by
SSPA’s model basin in Gothenburg and its
branch in Stockholm (which specializes in
hull engineering), working closely with Stena
Teknik. Construction started in summer 2009
and the vessel was launched in Gothenburg
in March 2010. Built on a 1:12 scale, the
unique model measures 15 m long by 3.3 m
across (equivalent to a ship of 182 x 40 m)
and, fully loaded, weighs 35 tons. Its electricdrive twin propellers are powered by a 60-kW
diesel generator, which also powers the test
equipment.
The AirMax hull has two main components,
a hullform machined from polyurethane foam
in four sections and a steel box to which
the sections are glued. The box provides the
vessel’s structural strength and contains its
machinery, including the generator, most
of the test equipment and the fans that
pressurize the air cavity. The hull, covered
in fiberglass and painted to correct surface
roughness, is cleaned before every test for the
lowest possible surface friction.
The reason the designers selected a model
scale of 1:12 is that they found an off-theshelf propeller that was suitable to the
project. Not having to design and build a
unique propeller saved the project a lot of
time and money, says Nordhammar, while
also fitting into a good scale for testing.
Whether or not a full-scale AirMax will use
conventional propellers will be decided in
the future; the first task for the team is to
optimize the hull.
“The propeller is optimized for the hull
with the cavity covered,” says Nordhammar.
“For now, the tests are only comparing hull
performance with and without the cavity.
Therefore, whatever propeller was selected
would have had the problem of being not
optimized for one of the test conditions,” he
explains. “We hope that, when we optimize
the propeller for the air cavity, we will gain
back a few percent efficiency.”
Modifications, made at
the bow and stern, were
designed to give the hull the
most extensive flat bottom
possible, thus maximizing
the opportunity for wetted
surface reduction.
The real-life laboratory for these unique
model tests is a picturesque fjord on Sweden’s
west coast, just over an hour’s ride north of
Gothenburg. Experimentation began last
year in a series of tests performed with the
air cavity covered by special inserts, so that
the hull could be assessed as a normal surface
against which to reference any air cavity
effects. A series of tests with the air cavity
in operation followed. Up to now, these
tests have been performed only on days with
flat water and very little wind, because they
need to prove the technology in a baseline
environment before subjecting it to the
variables of nature.
The challenges of collecting data in
nature made a good test and measurement
methodology critical to the project’s success.
“Measuring speed through water accurately
Fall 2011 • Surveyor | 13
measured by anemometers on
board, while wave data (wave
height, period and direction)
are measured by a buoy and
current speed is measured by
a floating device.
Wind effects on performance
are removed by standard
compensating calculations,
but when the breeze is too
strong the tests have to be
postponed. In the end, by
deducting current velocity
from speed over ground they
can calculate the model’s
speed through water.
The hullform is machined
from polyurethane foam.
Members of the AirMax
crew: Henrik Nordhammar,
Stena Teknik; Abolfazl
Shiri, Post-doctoral student,
Chalmers University;
Jacob Norrby, Stena Teknik;
Rickard Bensow, Professor in
Hydrodynamics at Chalmers
University; and Michael LeerAndersen, SSPA.
is crucial in this kind of work. Yet, one of the
great mysteries of mankind is that you can only
measure speed through water to within a few
tenths of a knot, which is not very accurate
in this context,” says Nordhammar. “When
you want to verify speed-power relationships
in real life, you can only measure the power to
within one percent or so reliably. Altogether,
you miss out on about five percent, so you
can’t get an accurate verification of the speedpower curve.”
With neither speed logs nor Doppler logs
giving sufficient accuracy, the research team
worked with SSPA to assemble a reliable
seaborne measurement laboratory. They settled
on measuring the vessel’s speed over ground
using a global positioning system (GPS), which
also measures its trim and heel. Propeller load
is measured by combined thrust and torque
hub dynamometers developed specially for
the project. Wind forces and direction are
Understanding the behavior of water along
the ship’s bottom is another crucial part of
the experiment. Eight cameras mounted in
the hull observe water flows in and around
the air cavity and the propellers. Meanwhile,
computers in the wheelhouse control and
monitor air pressure and level inside the
cavity, as the experimenters try to get the
surface of the air cushion surface as close
as possible to the baseline (the lowermost
level of the hull) without letting air escape.
If they can establish a stable air pocket, they
can minimize the amount of energy consumed
by pumping and limit friction caused by
escaping air.
Promising Results
Because the results of this testing may become
the basis of future design criteria, there is a
lot riding on the accuracy of their data. In
this aspect of the project, the Stena team has
relied heavily on the technical capabilities
contributed by SSPA – in fact, the ‘captain’
of the AirMax, Mats Turesson, is an engineer
with the SSPA Measurement Lab.
“We are still in a basic research phase of the
project, where we are trying to understand the
physics involved,” says Nordhammar. “If we
want to try the AirMax concept on different
vessel types in the future, we must know with
certainty all the design parameters, so that
we can go straight from the concept to the
design phase. To get that knowledge, we are
trying to make a laboratory out of nature in
a way that hasn’t been done before. Besides
that challenge, it is very difficult to make
accurate measurements in nature anyway, and
requires specialists to get good results,” he says.
“It would have been impossible to do all this
without SSPA.”
14 | Surveyor • Fall 2011
The main task for this first phase of testing
is to find the right adjustments for vessel
trim and air pressure in the cavity. Because
it will take hundreds of tests to have
statistically-significant data, the investigators
have concentrated on running the AirMax
at service speed equivalents of 12 and
14 knots.
Back when they were working with a 4-meter
model in the SSPA towing tank, the team ran
many more tests at many more speeds and from
the data drew the speed-power curves for the
AirMax design. The reason to concentrate the
real-life testing at only two speeds is to get two
solid data points for comparison with those
curves. If the points match up with the curves,
says Nordhammar, they will be able to assume
good correlation for other speed ranges.
So far, they have achieved resistance
reductions between 20 and 25 percent, against
a wetted surface reduction of about 30 percent.
“The results from the first testing season are
very promising; they indicate that we could
save quite a lot of energy with that hole in the
bottom,” says Ulf Ryder, CEO of Stena Bulk.
“That said, we don’t know yet what a yard
would charge us to build an AirMax vessel.
Experience tells us that yards resist change. We
do know the AirMax will be more complex to
build and will need more steel than a regular
ship. As for calculations of payback time and
so on, we will figure out all that when time
comes to build.”
While building an AirMax may be years away,
the experiment has already yielded potentially
valuable data for other ship types, particularly
passenger vessels. These came
me to light while
Stena was investigating usee of the air cavity
concept in a ro-ro passengerr (ro-pax) ferry
project for service in an areaa with highly
restricted length and draft. In
n order to fit the
cargo requirements, the designers
gners widened
the beam to 34 meters, applied
ed the AirMax
concept and discovered something
ething totally
unexpected: a kind of self-repairing
pairing damage
stability.
While the results bear further
investigation, the data does lead
Nordhammar to speculate on a possible
revolution in ship design. “A wide ship
is more stable but has larger resistance
than a narrow ship. If this resistance
can be countered via an air cavity, it
then becomes economical to build
wider, shallower-draft ships than was
previously possible,” he explains. “This
would mean that wide ships could have
the same resistance as any other ship,
but with an absolutely unprecedented
built-in level of safety. You could have
water on deck and still have damage
stability, for example – a very interesting
possibility, especially for passenger
vessels.”
Ulf Ryder,
CEO,
For the AirMax, this second season of testing
will determine the kind, character and extent
of future experimentation. One task ahead is
to look for ways to further cut drag. Although
the present 20-25 percent drop in resistance
and 30 percent reduction in wetted surface
is not fully in line with investigators’ initial
hopes, it is a good result that encourages
further research, says Nordhammar. One new
avenue will be explored by a post-doctoral
engineering student from Chalmers Technical
University (SSPA is located on the Chalmers
campus) who will study wave behavior and
the interaction between water and air inside
the cavity.
Stena Bulk
A concept rendition of
the AirMax as a chemical
carrier, giving a good view
of its patented, flattened
Clearly, if air cavity drag reduction is to deliver
on its decades-old promise, every angle of
the technology must be explored – and there
are a lot of angles to it. Fortunately, says
Nordhammar, the Stena environment supports
even lengthy research and development. “This
is a fascinating project,” he says, standing
on the deck of the AirMax, looking
off into the distance as it glides
through the Lisefjord.
“There are always
new things to
discover.” ❖
bulbous bow.
Tests showed that, as the ship heeled over
in the damage condition, the air escaped
from the cavity, the water entered
red
the space and, when it contacted
ed
the ceiling of the cavity,
effectively added to the hull’s
wetted surface; this gave the
vessel a stronger righting
moment that brought it back
to a stable condition.
Fall 2011 • Surveyor | 15
Meeting the Post-Tin Challenge
Anti-foulings move forward as tin fades into history.
here are said to be around 4,000
species of ‘fouling organisms’ – flora
and fauna that float through the sea
looking for ships to torment. They come in
all shapes and sizes: tenacious microscopic
pests like bacteria, diatoms and algae;
familiar sticky critters like oysters, barnacles
and tubeworms; and lush grasses and kelps
greater than 10 meters long. The ‘marine
fouling communities’ in which these vandals
congregate can look amusingly weird hanging
off a vessel in drydock, but their effects on
ship speed and energy efficiency can be quite
serious. When no anti-fouling paints are
used, hull fouling could result in an increase
in fuel consumption of up to 40 percent and
a total increase in voyage costs of up to 70
percent, according to some estimates.
T
For three decades, the main approach
to hull protection was to apply biocidal
coatings in which the active ingredient
was tributyl tin (TBT), part of a family of
biocidal compounds known since 1850
as organotins. Soon after organotins were
introduced into marine paints during the
1960s, TBT emerged as one that was both
16 | Surveyor • Fall 2011
extremely effective and relatively inexpensive
and quickly became the maritime industry’s
biocide of choice. When TBT was discovered
to be toxic far beyond the area of the ship,
affecting ‘non-target’ species like oysters and
accumulating in the marine environment, and
in parts of the food chain, an international
movement began to ban use of the material.
The TBT issue was raised at the IMO in 1988.
Japan banned use of organotins in 1993, with
IMO and the European Union soon moving
in the same direction.
Today, biocidal marine coatings are governed
under IMO’s International Convention
on the Control of Harmful Anti-fouling
Systems on Ships (the AFS Convention),
which entered into force in September
2008, and the EU’s wider-ranging Directive
98/8/EC of the European Parliament and of
the Council Concerning the Placement of
Biocidal Products on the Market (the Biocidal
Products Directive (BPD)), which entered
into force in May 2000. The BPD regulates
biocides for 23 categories of use (anti-foulings
are in Category 21) and provides stringent
rules for their testing and approval. With
the EU’s TBT Regulation of July 2003, all
EU-flagged ships had to comply with a set of
rules similar to those of the AFS Convention.
Together these documents reshaped the marine
paints market and refocused the research and
development efforts of whole sectors of the
paint industry.
Although TBT was officially banned in 2008,
the post-tin world began taking shape almost
a decade earlier, when manufacturers read the
writing on the wall and began working out
the product strategies that would take them
into the future. In 2002, most major marine
paint makers volunteered to eliminate TBT
from their product ranges, and within a few
years it had disappeared completely from
the shelves of the world bazaar – the kind of
sweeping action possible in a relatively small
playing field. According to the International
Paint and Printing Ink Council (IPPIC), the
trade association for the coatings sector, 80
percent of the market is divided among just
five companies: AkzoNobel (via its subsidiary
International Paint), Chugoku, Hempel,
Jotun and PPG (which acquired Sigma
Coatings three years ago).
chemical reaction – hydrolysis – in
which an ‘erosion zone’ manifests
on the microscopic outermost layer
of its surface where the polymer
becomes dissolvable in water. As
the ship moves through the sea,
this layer undergoes a continuous
process of wear that results in a
constantly polished or smooth
surface. As these ‘self-polishing’ or
ablative binders wear down, they
continually expose new biocidal
surface.
“Silyl technology is amazing,” says
Bjoern Wallentin, Global Sales
Director for Hull Performance
Solutions at Jotun. As a chemist
with Jotun, he spent five years in the
laboratory working on the company’s
flagship Sea Quantum range of silyl coatings
Bjoern Wallentin,
Global Sales Director for
Hull Performance Solutions,
Jotun
By the early 2000s most manufacturers, if
not all, had already spent years developing
TBT alternatives, introducing products that
have evolved over the past decade in two
major directions: biocidal anti-fouling paints
and ‘fouling release coatings.’ Biocidal antifoulings typically use biocides mixed in a
polymer binder system that slowly releases
them into the water. Fouling release coatings
rely not on biocides to keep the hull clean,
but on silicone compounds that create a kind
of nonstick surface on the hull.
The Rise of Silyls
As might be expected, biocidal anti-foulings
depend on two major factors for success –
the efficacy of the biocide (or biocide combinations, as there is usually at least one for animal
life and one for plants) and the chemistry of
the binder, which holds the paint ingredients
together and delivers the biocides to the marine
environment. A variety of delivery systems
(binders) are proving successful in the market
today, among which silyl-acrylates can be
considered the most advanced.
Silyl-acrylates were first developed in Japan in
the early 1990s and have emerged on top of the
worldwide coatings scene for two main reasons,
both related to their behavior in water. When
the polymer contacts seawater it undergoes a
Fall 2011 • Surveyor | 17
prior to the product’s release in
2000. Developed in conjunction
with Nippon Oils and Fats
(now NKM), it was the first silyl
acrylate coating to crack the
international market.
Evert van Rietschoten,
Product Manager of
Marine Coatings,
PPG
“It all comes down to a chemical
reaction that takes place between
the water and the resin in the
outer 10 microns of the surface of
the paint. The polymer consists
of a hydrocarbon chain that has
linked-in groups attached to it,
of which the silyl is one. The
hydrocarbon chain with the silyl attached
is totally insoluble in seawater. Once the
hydrolysis reaction takes place, the silyl
group is released and the hydrocarbon chain
becomes water-soluble. It leaves the paint
surface and contributes to the smoothingdown effect, because water is more readily
available at the high points, or peaks, of a
rough surface,” Wallentin explains.
“The biocide needs to be delivered in a
very controlled way over time. Because
hydrolysis is a chemical reaction, it is totally
predictable, which is why manufacturers can
make coatings with specific lifetimes – a span
from two to seven-and-a-half years is typical
for a silyl coating today, and the only thing
you need do for the ship to trade longer
18 | Surveyor • Fall 2011
than that is to add more thickness to the
coating,” he says. “The thickness of a sheet
of copy paper is about 75 to 80 microns,” he
adds. “The thickness of three to five of them
together is the thickness you need of a silyl
anti-fouling to give you five years of antifouling protection for a hull.”
The hydrolysis process leads directly to the
second reason why silyl compounds are so
desirable: it has been demonstrated that
their self-smoothing effect decreases hull
resistance in water and makes the ship more
fuel efficient.
“Energy savings is more in the forefront
today than it has been for a long time;
bunker fuel costs about twice what it did
just four years ago, so now the industry
is focusing on fuel economy,” says Evert
van Rietschoten, Product Manager of
Marine Coatings for PPG. “The smoothing
mechanism contributes to fuel savings, and
the focus of our research is better control
of that mechanism, such that the binders
dissolve in seawater in a controlled way and
that they release the active ingredients in a
controlled way.”
“Silyl-acrylates are the state-of-the-art antifoulings technology today, having proven to
deliver the most constant performance over
the years,” van Rietschoten continues. “But
these are difficult and expensive polymers to
make, which means silyl-acrylate products
are more costly. That’s one reason why
silyl-acrylates are not as widely used as one
might expect, and also one of the reasons
why there are more coatings technologies
out there. With the TBT anti-foulings, it
took about 20 years after their introduction
in the 1970s to optimize costs. We’re not in
that situation yet with silyl-acrylate antifoulings. That said, the shipping industry
spends less than one percent of its running
costs on coatings and more than 50 percent
on fuel. This means the coating industry has
something substantial to offer the maritime
industry in terms of fuel savings. But fuel
price is only one aspect of the big picture,”
he adds.
Another aspect is that the person who pays
for the coatings and the one who pays for
the fuel are not always the same. Wallentin
points out that the incentive to take cheaper
coatings will always be there and on that
point, urges buyers to carefully read the label
on their paint.
“The silyl component is one of the main
factors driving the cost of silyl products; as a
result, you may have paint makers producing
silyl coatings that use multiple resins and
contain very little silyl,” Wallentin says.
“It’s a bit like washing powder used to be
in the old days – the boxes were huge, but
they were mostly filler. In this case, however,
a small percentage of the key component
won’t do the job. In order to get silyl
The Biocidal Products Directive
n 1993, the European Commission
proposed a Directive to establish a single
European biocides market through a
harmonized authorization system based on
risk assessment and technical analysis. This
became Directive 98/8/EC of the European
Parliament and of the Council Concerning
the Placing of Biocidal Products on the
Market, known as the Biocidal Products
Directive (BPD), which entered into force
on 14 May 2000.
I
The BPD defines biocidal products as: “active
substances and preparations containing one
or more active substances, put up in the
form in which they are supplied to the user,
intended to destroy, deter, render harmless,
prevent the action of, or otherwise exert a
controlling effect on any harmful organism by
chemical or biological means.”
Thus, despite being a ‘biocide’, a biocidal
product does not actually have to kill. This
makes the scope of the BPD very wide,
covering 23 different product types (antifoulings are in Group 21), a full list of which
is provided in BPD Annex V.
The BPD achieves its aims using a two-stage
regime calling for rigorous evaluation of
both biocidal active substances and biocidal
products so they do not pose unacceptable
risks to people, animals or the environment.
Only those biocidal products containing
an active substance approved in Annex I
of the BPD are authorized for use. Product
evaluation is undertaken by individual
member States, while decisions regarding
Annex I inclusion
are taken at the
European level.
Industry is charged
a fee for this process
that varies by
member State.
Once an active
substance is included
in Annex I, member
States can authorize
products containing
it. Once authorized
by one member
State, the product
becomes eligible for
mutual recognition
and authorization by
other member States.
None of this comes
for free. Charges
for the service are
levied by each State
for each step of the
process. ◆
Fall 2011 • Surveyor | 19
performance, the silyls need to be
the dominant ingredient in the
resin; they have to be in what I
call ‘the film-forming phase’ so
that, when the paint dries, it is the
silyl that makes the film while the
other resins just sit inside it.”
Torben Rasmussen,
Group Product Manager
of Fouling Control,
Hempel
The problem with a secondrate resin system is that it can
ultimately help the formation of
fouling communities,he explains.
It starts when the lower-quality
resins exit the anti-fouling and leave behind
a vacuole or microscopic empty spot in the
coating surface. When vacuoles take over the
surface layer they can prevent the polymer
from dissolving at the right speed for proper
release of the biocide. Should this ‘leach layer’
or ‘inactive zone’ grow to, say, 70-100 microns
in thickness, it will make it very difficult for
the biocides to reach the surface in sufficient
volumes to prevent fouling.
Slippery Coatings
get Slipperier
As an alternative to biocides, paint
manufacturers began introducing silicone
fouling release coatings in the early 2000s.
These provide a nonstick surface to which
fouling organisms cannot stay attached
once the ship is in motion. A nonstick
20 | Surveyor • Fall 2011
coating adheres to a steel hull through an
intermediate ‘tie-coat’ that attaches it to an
under-layer of one or more anticorrosive or
preparatory epoxies.
The first generation of silicone coatings was
noted for two problems in particular: the
coatings needed the vessel to be moving
at a certain velocity to be able to release
the fouling organisms, and proved less
effective at slower ship speeds; in addition, a
bacteriological slime would start forming on
the nonstick surface within about two years
after application, resulting in a noticeable
drop in vessel efficiency. An interesting
solution to these issues, introduced by
Hempel in 2008, uses hydrogel technology
from the medical world to keep fouling
communities from sticking around the ship.
“We asked our R&D people to come up with
something that could prolong the slimefree period and could cope with low-speed
vessels,” says Torben Rasmussen, Group
Product Manager of Fouling Control for
Hempel. “They came up with this hydrogel
technology, which is used extensively in
wound dressings, transplants and other areas
of medicine, and applied it to our Hempasil
X-3 formulation.
“Certain water-soluble polymer chains are
described as being ‘super-absorbent’, forming
a kind of micro-layer of liquid – the hydrogel
– on top of the solid coating,” he explains.
“This layer contains some 95 to 98 percent
water and sits like a very thin layer of
stagnant water on the hull. It is our belief
that, for example, a barnacle larva will, in
a way, ‘perceive’ this hydrogel to be a liquid
because it contains so much water and, thus,
will not adhere to it. We can’t actually prove
this is what happens, but we can see that the
hydrogel effect works extremely well, even
under idle conditions.”
New technologies have brought another
advance for silicones that helps lower the
overall cost for owners choosing to go with
the pricey technology. “It is now possible
to get sufficient adhesion between existing
silicone and new silicone that we are able to
apply a new coating directly on top of an old
one without a sealer or tie-coat in-between.
We have even over-coated silicones from
other manufacturers – after a good cleaning,
of course,” says Rasmussen.
In the competitive world of hull paint,
advances in both silicone and biocidal antifouling technologies mean that there is room
in the market for everyone, he adds. “We see
an increasing number of owners interested
in advanced silicone coatings, but there will
still be a need for biocidal anti-foulings,”
he says. “Silicones are more expensive than
conventional anti-foulings, so a coating
that lasts seven years might not appeal to an
owner who intends to sell the ship within
five. Ultimately, the coating has to pay back
the investment in it.”
The AFS Convention
oncerns about toxic pollution by tributyl tin antifouling paints were first raised at the International
Maritime Organization in 1988. Now 20 years
later, swift action by the concerned nations of the world
resulted in entry into force of the International Convention
on the Control of Harmful Anti-fouling Systems on Ships
(AFS Convention). Under the terms of the Convention, from
September 2008 forward, no ships shall apply or re-apply
anti-fouling coatings containing organotin biocides – it
applies to all ships (except Navy ships), including fixed and
floating platforms, floating storage units (FSUs) and floating
production, storage and offloading (FPSO) units.
C
Ships of 400 gross tonnage and above engaged in
international voyages are granted an International Antifouling System Certificate to evidence compliance. Ships of
24 meters or more in length, but less than 400 gross tons,
that are engaged in international voyages have to carry a
Declaration on Anti-fouling Systems signed by the owner
or authorized agent. The Declaration must be accompanied
by appropriate documentation such as a paint receipt or
contractor invoice. ◆
The Future Depends on R&D
Coatings must also pay back manufacturers
for the increasingly high costs of
development and marketing. Economics,
politics and business practices all contribute
challenges to the appearance of new antifouling products in the post-tin world.
Some of the greatest challenges stem from
stringent environmental legislation created
to keep anything else like TBT off the
market. Most manufacturers are now looking
to the Biocidal Products Directive as the
leading indicator for their worldwide product
development.
“In the future, we will see fewer new
technologies on the market as a result of
the restrictions on the amount and type
of biocides you are allowed to use,” says
Rasmussen. “Biocidal materials or active
Fall 2011 • Surveyor | 21
ingredients are subject to local, regional or
global legislation, which are the chief factors
determining the product landscape. Under
the biocidal products directive in the EU, for
example, manufacturers have to demonstrate
that the biocides they supply exhibit minimal
environmental effects. This amounts to a very
expensive and comprehensive test package
that any biocide has to pass in order to be used
in any application, which limits the selection
of compounds available.”
Getting a product to market under the
BPD occurs in two steps: registration of the
active ingredient by the supplier; and product
approval. Suppliers of active ingredients need
to invest heavily to keep these materials on
the market.
“If you want to develop a new anti-fouling
based on new active ingredients, you run
into difficulties. Depending on local and
regional legislation, the supplier of a new
active ingredient sometimes has to invest $6
million over and above the development costs
in regulatory expenses, such as registration of
the active ingredient,” says van Rietschoten.
“On top of that, the coating supplier will
have to invest in product registration, which
brings additional costs and time investment.
This makes a huge entrance barrier to the
industry, and presents quite an impediment to
innovation as well.”
22 | Surveyor • Fall 2011
In addition to regulatory-related costs, there
is pressure from the rising cost of copper –
the price has tripled in the past two years.
Legislative acceptance is an aspect very
much in motion, in both Europe and in the
US, and companies find it difficult to predict
where that is going. While copper is still
king of the biocides, research into alternative
technologies is active and ongoing.
“In our development of anti-fouling
paints we aim to use biocides with the
shortest possible half-life, or the quickest
breakdown in the environment,” says
Wallentin. “Cuprous oxide is one of the
safest biocides you can use. We just published
the results of an experiment (in the Ship
Repair Journal, December 2010) in which
a marine environment was created in the
lab to test marine life acceptance of copper
at various levels; they adjusted quite well
to it,” he says. “Soon after the copper ions
are released into seawater they form copper
salts and compounds and become inactive.
Some 99 percent of all copper in the marine
environment has been put there by rivers
and underwater volcanoes. Having said
this, there are local waters, marinas and
bays that have a challenge with very high
concentrations of copper, but this is in many
cases caused by (excessive) underwater
cleaning of fouled hulls that had used lowerquality (polymer) anti-foulings containing
high levels of cuprous oxide,” he explains.
“By comparison, the half-life of the nowbanned TBT is quite long – measured in
months or years, depending on the local
marine environment. The biocides we use
today have much shorter half-lives, some
of which are down to an hour. So, in about
seven hours, they are down to less than
1 percent of the original concentration,”
he says.
Despite the best efforts of researchers, the
days where one basic coating type satisfies
80 percent of the market appear to be as
much a memory as TBT. “There is no single
coatings solution for all customers,” says
van Rietschoten. “There are so many paint
systems today because vessels operate in
different ways and require different solutions.
Ship operation, budgetary constraints and
environmental considerations all figure into
the owner’s decision on coating and we, as
paint suppliers, try to inform and advise on
that decision,” he says.
“We work with all parties to help innovation
and development of new anti-foulings,
but, in some cases, the entrance barriers
prevent some promising products from
commercialization,” he adds. “That
said, there is quite a lot of research and
development going on today – the industry
is not standing still. We and our competitors
are investing heavily in R&D to move
forward and, I would say, there is more
innovation to come.” ❖
Regulations Reflect
Coating Concerns
he first international regulation to
address hull fouling, designed to
minimize transfer of invasive aquatic
species, was accepted in draft form by the
Sub-Committee on Bulk Liquids and Gases
(BLG) of the IMO Marine Environment
Protection Committee (MEPC) when it met
for its 15th session in February this year.
IMO’s bio-fouling guidelines are expected to
establish an expanded regime for hull fouling
condition management and associated record
keeping. The main reason for this regulation
is concern that modern anti-fouling coatings,
whether foul-release or biocidal, have yet
to catch up with tributyl tin in terms of
preventing species migration.
T
Even well-maintained hulls can pose an
invasive species risk, according to a US
study of 21 in-service containerships, which
found that less than 1 percent of the hull
area of the vessels was colonized, but that
biodiversity in those areas was high. One
vessel was home to 20 different species,
concentrated mostly in such hard-to-clean
areas as the rudder, stern tubes and intake
gratings.
According to some estimates, fouling on
ship hulls (and other floating structures)
is responsible for some
87 percent of recorded
marine species invasions;
the issue was officially
raised at IMO in 2007. The
draft guidelines call for
an effective hull fouling
management system that
covers the hull and hardto-reach (niche) areas, and
are expected to lead to
increased attention to hull
treatment in drydocking,
monitoring and in-water
cleaning.
The upshot is that actions
additional to hull coating
will be needed in the
future to effectively fight
bio-pollution and spread
of invasive aquatic species.
The draft IMO guidelines
and the upcoming ABS
Guidance Notes on Hull
Resistance Management
reflect this new realization
and attempt to combat
the problem in a proper
engineering context. ◆
Fall 2011 • Surveyor | 23
Poison Paints & Magic Metals
A brief look at 3,000 years of fighting hull fouling.
A
n Aramaic papyrus dated to the
5th century BC leaves us a bit of
correspondence proving not only
that the search for the perfect hull protection
goes back a very long way, but also that
hope does, indeed, spring eternal:
“…the arsenic and sulfur have been well
mixed with the Chian oil that you brought
back on your last voyage, and the mixture
evenly applied to the vessel’s sides, that she
may speed through the blue waters freely
and without impediment.’’
The subsequent letter, in which the sender
complains that the treatment didn’t work
long enough to justify the cost or the effort
of application, is lost to history – but anyone
with a ship to coat or a coating to sell can tell
you it surely was sent.
The CUTTY SARK’s
hull was covered
in Muntz Metal.
Researchers tell that, beginning in Antiquity,
waxes and poisonous oils formed the basis
of an endless stream of attempts at hull
protection. The wide-ranging ingredients of
former times included salts of copper, arsenic
and mercury, linseed oil, shellac, tar, plant
resins, turpentine and naphtha. By the 14th
century, various compounds containing pitch,
tar, sulfur and toxic plant oils were being
applied to ship hulls to discourage surface
attachments and prevent attack by the teredo
or shipworm. Another practice, in use by at
least the 15th century, was to cover the lower
hull with thin strips of ‘sacrificial planking’
intended to catch the shipworm and be
replaced before the pests penetrated into the
real body of the vessel.
Historian Samuel Eliot Morison, in Admiral of
the Ocean Sea, his 1943 Pulitzer Prize-winning
biography of Christopher Columbus, records
that:
“All ships’ bottoms were covered with a
mixture of tallow and pitch in the hope of
discouraging barnacles and teredos, and every
few months a vessel had to be hove-down
and graved on some convenient beach. This
was done by careening her alternately on
each side, cleaning off the marine growth,
re-pitching the bottom and paying the seams.”
Patent records pick up the trail of antifouling developments beginning in the 17th
century. The first patent for an anti-fouling
was issued in 1625 in England to one William
Beale, whose coating concoction contained
a mixture of iron powder, copper and cement
and was described as rendering the hull and
rigging ‘incombustible.’ In 1791, William
Murdock patented an anti-fouling varnish
made with iron sulfide, zinc powder and
arsenic. His contemporaries in America and
England, meanwhile, experimented with
biocidal paints built on such ingredients as
arsenic, brimstone, lime, mercury, pitch
and tar.
By 1863, when James Tarr and Augustus
Wonson were granted a US patent for a
copper oxide and tar anti-fouling paint,
there were over 300 patented hull coating
formulations on record. The ‘patent paint’
market of the time appears to have become
24 | Surveyor • Fall 2011
somewhat like the patent medicine market,
according to this lament published in the 1872
Transcripts of the Institute of Naval Architects:
“It is probable that under no other head
in the whole range of the Patent Office
Records is such a mass of ignorance, absurdity
and charlatanry exhibited, as in these antifouling patents. One or two of the best
have proved palliatives (no more can be
said for any of them), and are, for want of
anything better, more or less in practical use
…some of the most recently patented are
grotesque in their ignorant absurdity – as
for instance, one in which a farrago of the
soluble drastic purgatives (such as colocynth)
of the apothecary’s shop is mixed up with
incompatible resinous fluids, to scare away the
unhappy zoophytes.’’
Shortly after Japan’s Patent Monopoly Act
became law in 1885, the country’s first patent
was granted to a man named Zuisho Hotta who
had developed an anti-fouling paint made of
lacquer, powdered iron, red lead, persimmon
tannin and other ingredients. When lacquering was deemed successful after trials by the
Japanese Admiralty, the technology was
tested on vessels in Russia and in laboratories
in Europe and the United States, though it
ultimately made little impact.
Two of the most popular 19th-century antifoulings were developed during the 1850s:
‘hot plastic paint’, patented by James
McInness, which used copper sulfate as the
biocide in a soap-like mixture that was applied
hot over a quick-drying primer of rosin varnish
and iron oxide; and a related formulation
of rosin and copper developed in Italy and
known as the Italian Moravian coating. These
remained in use for decades, with hot plastic
paint technology becoming the subject of an
R&D program by the US Navy in the early
20th century.
in 1670 to Sir Philip
Howard and Francis
Watson for a method
of sheathing ships in
milled lead, produced
by a new invention of
theirs that used rollers
to manufacture it as
sheets. The product
proved so successful in
trials that the Admiraltyy
ordered many of its
ships sheathed in lead.
The practice continued
until about a hundred
years later, when it was
discovered that the
sheathing increased
ils
corrosion of the iron nails
and fittings that held thee
ships together.
As interest in lead faded, other metals were
tried. A 1727 patent, issued to Benjamin
Robinson and Francis Hankshee, covered the
use of brass, copper, iron and tin plates for
anti-fouling purposes. After about a decade
of experimentation with copper, the British
Admiralty in 1761 floated the 32-gun frigate
HMS Alarm as the first ship whose hull was
entirely sheathed in the metal. The vessel was
dispatched to the West Indies, where fouling
was a particularly severe problem. When the
vessel returned to England a few years later,
her sheathing was examined and found to be
clean as the day it was installed. Unfortunately,
when the Alarm was surveyed in 1766 it was
found that, while the wood was intact, the iron
fittings holding the ship together – including
the rudder straps – were dangerously corroded.
Over time, metallurgical knowledge advanced
and iron fittings and pure copper sheets were
replaced by alloys more suited to the service
and, by the late 1800s, many iron and steel
ships were protected by sheathing made from
copper alloys.
The Royal Navy first
developed the technique of
applying copper sheathing
to ship bottoms to improve
sailing performance. The
first wooden ship to be fully
sheathed in copper was the
32-gun English frigate, the
HMS ALARM, in 1761.
Magic Metals
Metallic hull protection may have been in
use even before specialized paint. It has been
reported that the shipowners of Ancient
Phoenicia used copper strips on their vessels
to inhibit fouling. Copper remains the leading
biocide ingredient in coatings today.
Lead also has had its day as a miracle metal.
First used in Antiquity, lead gained popularity
as an anti-fouling during the 16th century,
when Spanish ship operators began nailing it
to their hulls. An English patent was issued
The first copper alloy patent was granted in
1800, to an inventor named Collins who
developed a copper-zinc formulation. Many
copper alloy patents followed, including a
bronze in 1817 and a brass in 1823. In 1832,
a Birmingham, England metal-roller named
George Muntz received a patent for a 60-40
copper-zinc formula with a trace of iron in it.
Named Muntz Metal or Yellow Metal, it cost
around two-thirds of the price of pure copper
while doing exactly the same job and became
the hull protection of choice in the golden
age of the clipper ship. It was even somewhat
Fall 2011 • Surveyor | 25
organotins migrated into maritime use from
the agricultural sector, where they had been
successfully used as pesticides.
Organotins proved extremely effective against
a very wide range of fouling species at very
low concentrations. Because they were also
inexpensive, they became the leading biocide
ingredients for a generation of hull paints. By
the late 1970s, one organotin in particular,
tributyl tin (TBT), had emerged as the biocide
of choice. Eventually, about 80 percent of
the world’s merchant fleet was protected by
TBT-containing hull paints.
Self-polishing TBT
anti-foulings have
also passed into
history.
ablative, wearing down with use to continually
expose good biocidal surface. The material
found wide application and is still used today
to produce corrosion-resistant machine parts.
To Tin and Beyond
For all its popularity, copper sheathing had
a severe drawback in that it could cause
corrosion of the iron and steel ship it was
protecting. Worse yet, through electrolytic
action a copper-sheathed ship could even
damage the hull of an unsheathed ship
moored next to it. This resulted in a US Navy
order that no sheathed vessel should ever be
moored next to an unsheathed one. Besides
the corrosion problem, copper was heavy (one
19th-century Navy calculation determined
it would add some 250 tons to a cruiser)
and expensive. Trying to eliminate copper
sheathing while still holding onto its benefits,
extensive research towards the end of the
century looked into electroplating hulls with a
film of copper, but led nowhere. As anti-fouling
paint technologies improved, sheathing faded
from use and, during the early 20th century,
most navies and commercial enterprises turned
to paint as the way forward.
After the Second World War, copper became
the basis of the first biocides used in the
industrial-scale production of anti-fouling
paints. The most common forms were cuprous
oxide, which is red, and cuprous thiocyanate, a
pale-cream compound used in brightly-colored
paints. While copper works well against animal
life, it is less effective against plants, so to
fight floral attachment modern anti-foulings
incorporate a secondary or ‘boosting’ biocide.
Through the 1950s, typical boosting biocides
included mercury and arsenic, but these
poisons were largely replaced in the 1970s by
organotin compounds. Known since 1849,
26 | Surveyor • Fall 2011
To make efficient use of TBT, marine paint
manufacturers developed ‘self-polishing’ coatings, which wear down predictably rates as a
ship moves through the water and, in so doing,
release the biocides they contain at controllable rates. This concept revolutionized the ship
coatings industry by permitting predictable
intervals between drydocking, with manufacturers able to offer anti-fouling protection for
periods ranging from six months to five years,
depending upon the composition of the paint
and the amount of TBT present. Self-polishing
or self-smoothing polymers are still the delivery
mechanism for biocidal compounds.
Cheap and dependable, TBT became the
king of biocides. Unfortunately, organotins
not only killed hull pests, but also affected
non-target species like oysters and
accumulated in the marine environment.
Once this became known, the IMO moved
to adopt a resolution in 1990 recommending
the elimination of TBT anti-fouling paints.
Eight years later the resolution was passed
and after another four the International
Convention on the Control of Harmful Antifouling Systems on Ships (AFS Convention)
was written. The AFS Convention slowly
moved forward and the TBT ban entered into
force in September 2008.
By that time, the leading marine coatings
manufacturers were well-prepared for the
demise of TBT. They undertook a voluntary
ban of the material in 2002, eliminating
organotins from their product lines and
introducing the first versions of many of the
hull protection products in use today. By 2003,
the Journal of Coatings Technology could report
that “Owners are taking advantage of a wide
array of tin-free anti-fouling technologies to
fit their budgets and operational needs. These
range from top-of-the-line silyl polymer-based
coatings and self-polishing copper acrylate
coatings to tin-free ablative coatings.” ❖
The Cyber-Resurrection of
Our Lady of the Martyrs
A unique methodology has married nautical archaeology with history, engineering
and computer science to ‘rebuild’ a ship type not seen in centuries.
W
ith a voracious hunger for treasure
and territory, the Kingdom of
Portugal injected an animating
force into the Age of Exploration. Its
seaborne trailblazers planted colonies
across the Atlantic, erected trading posts
around the coast of Africa and opened trade
routes to India, China and Japan. They
built a wide-ranging commercial network
that streamed wealth and power into the
country’s ports, chief among them the
capitol city of Lisbon. Just up the Tagus
River from the Atlantic Ocean, Lisbon’s
rich markets promised great fortunes to the
merchant-adventurers who dedicated their
lives to trafficking in exotic goods.
the victuals, equipment and personal cargoes
of the 450 people on board.
And so for centuries Lisbon played the
Lorelei, singing ceaseless dreams of avarice
to an endless stream of fortune-seekers,
rewarding most but luring many to a dismal
doom. Between 1498 and 1600, for example,
some 220 merchantmen were lost on the
India route alone, many of them condemned
to anonymous repose in the last few leagues
of ocean before the mouth of the Tagus.
Sand bars and shoals made the opening
to the Tagus estuary a death-trap, where,
e,
caught in the grip of a storm, a large proud
oud
vessel could be reduced to a mass of bobbing
bbing
sticks in a surprisingly short time. There,
e,
many ships wrecked as spellbound soldiers
iers
watched helplessly from the nearby Fortress
rtress
of São Julião da Barra, a stronghold on
a promontory from which they could
control all human activity in the area,
nd
yet had less influence than a grain of sand
on nature’s rage.
Meanwhile the cargo of precious peppercorns, bulk-shipped in bins, floated away
in an immense black tide that eventually
trailed miles down the coast. Salvors
managed to reclaim much of it, although
scavengers scooped up a share for themselves
and nature kept its own portion trapped
with the wreckage on the sea floor. The
wreck site was only about nine meters
deep, and salvage efforts over the next
few summers retrieved most of the ship
ship’ss
equipment, armaments and remaining
ng
cargoes. Soon after, Nossa Se
Senh
nhora
Senhora
dos Mártires passed into
to
history as a notatio
ion
n
notation
in a forgotten
en
accide
dent
nt
accident
On approach to the Tagus, the ship
encountered a heavy ocean storm off Cascais
Beach and Captain Manuel Barreto Rolim
ordered anchors dropped. The blow kept
on the next day and, seeing a ship ahead
of them run aground, Rolim decided to up
anchor and race for the safety of the estuary.
The bold move failed halfway to the goal,
just in front of São Julião da Barra, when
his hull was holed by a submerged rock and
began to sink. Within hours, the sea’s savage
battering had the once fine ship looking like
an ancient wreck.
hat
One of the ill-fated ships to perish at that
ur
spot was Nossa Senhora dos Mártires (Our
Lady of the Martyrs), which came to a
cruel end on 14 September 1606. She had
left Cochin, India nine months before,
laden with 220 tons (500 cubic meters))
of peppercorns – an extremely valuable
commodity at the time – and about
s,
three hundred more tons of spices, silks,
her
porcelains, precious metals, jewels and oth
other
mon
ong
exotic products that were jammed in among
Fall 2011 • Surveyor | 27
potential (for which special authorization
had to be obtained). Worrisome to UNESCO
(United Nations Educational, Scientific and
Cultural Organization, which designates
world heritage sites) and widely disparaged
as a treasure hunter’s law, the legislation was
repealed in late 1995 by the newly-created
Ministry of Culture and work on the Pepper
Wreck, among other sites, was allowed to begin
in earnest.
Although not of high value from the treasure
hunting perspective, the Pepper Wreck was
a goldmine for nautical archaeologists and
maritime historians, to whom it offered a rare
glimpse at a type of ship that, for all its fame,
was a mystery: the armed merchant vessel
known as the Portuguese nau.
Return to Light
Recovery of artifacts from
OUR LADY OF THE MARTYRS.
report and an anonymous data point in the
accumulated apocrypha of local treasure lore.
Lost and Found
When scuba diving became a pastime in the
1950s, long-told tales of sunken wealth made
the area around São Julião da Barra a favored
destination of sportsmen and treasure seekers,
who found and scavenged many of the subsea
tombs. In the late 1970s enthusiasts noted a
wreck site that, when surveyed by Portugal’s
National Archaeological Museum in 1993,
revealed a hull fragment mired in peppercorns
and surrounded by objects dating to the turn
of the 17th century. Designated SJB2 and
referred to as the ‘Pepper Wreck’, a search of
historical records led to its identification as
Nossa Senhora dos Mártires.
Found at last, the ship still received no help
from the authorities in the place she once
called home. A strange piece of legislation,
drawn up that year for what was then the
Lisbon Secretariat for Culture, treated
underwater archaeological sites like resources,
somewhat akin to mineral reserves. Under its
provisions, no sunken ship could be excavated
without first obtaining bank guarantees of £1
million ($1.5 million at the time) that would
be remunerated by a share of the recovered
artifacts.
The move sought revenue from the sale
of ‘repetitive’ treasures – chests of coins,
barrels of delftware and the like – and as a
consequence, virtually halted research on
all sites without recognizable commercial
28 | Surveyor • Fall 2011
For roughly 150 years starting at the close of
the 15th century, the nau served Europe as the
workhorse of discovery and long-range trade,
with each maritime nation developing its own
version of the concept. Originating in Italy,
where it was known as a caracca, the nau was
called a carrack in England, a caraque or nef
in France and a carraca or nao in Spain. The
vessel concept evolved out of medieval designs,
such as the caravel and cog, to provide the
greater cargo capacity, seaworthiness and sail
power demanded by the increasingly longer
merchant voyages that characterized the Age
of Exploration.
Trying to satisfy ever-growing technical needs
made the nau a design in constant evolution,
with size, sail plan and other details large
and small undergoing periodic development
through experience. As a result, there is no
definitive technical illustration of a typical nau
in the historic record the way there is for, say,
a galleon – which is what the nau evolved into
in the late 16th century. There isn’t even much
in way of archaeological remains, as only three
naus have ever been excavated.
Although interest was high when the
Pepper Wreck excavation began in 1996,
the expectation was that it would be a fairly
standard archaeological exercise of extracting,
preserving, analyzing and trying to understand
the scant remains: a portion of the keel
amidships, eleven frames and some planking,
which together account for about 10 percent
of the hull surface. Instead, a string of unusual
events brought the unlucky ship a post-mortem
miracle, in which an inspiration brought about
an act of academic alchemy that transformed
those few fragments into a vision of the
vessel fully outfitted, rigged and loaded – the
first close look at a nau design in over three
centuries.
Nossa Senhora dos Mártires’ return to
light began with a seemingly innocuous
administrative decision: the Ministry of
Culture sent as project manager a young
civil engineer named Filipe Castro to
organize, plan and manage the excavation.
He had taken the assignment with great
interest, shipwrecks having fascinated him
since childhood, but with no idea that this
old ship would change the course of his
future, and he the course of its history.
Rebuilding a Ghost
“As a manager, I was simply gathering data
for the project when I began reading old
shipbuilding treatises. Because I am an
engineer, I discovered I could understand the
texts very well,” Dr. Castro recalls. “I was also
able to explain to my colleagues what the
old authors were writing about, which drew
the attention of the people in charge, who
eventually suggested I go for a master’s degree
in nautical archaeology.”
Castro was accepted by the Nautical
Archaeology Program at Texas A&M
University in 1998, beginning a collaboration
between Texas A&M and Portugal’s National
Center for Nautical Archaeology and the
Technical University of Lisbon that continues to this day. Affiliated with the Institute
of Nautical Archaeology since 1976, Texas
A&M’s archaeologists have excavated wrecks
in some 30 countries, and the program remains
one of most respected of its kind in the world.
Castro alternated between the school and
the wreck site for four years, the Master’s
degree becoming a PhD that led to a teaching
position he has held since 2002. Along the
way, he got the idea to bring together nautical
archaeology, history, marine engineering
and computer graphics with the goal of
‘reconstructing’ the ship as a 3-D model.
The ambitious plan intended to quilt together
scraps of an information disapora – such as
operational remarks from ship logs and sailor
dairies, visual data from coins and artworks,
design details, general arrangement and sail
plans from administrative records, contracts
and technical texts – and create an electronic
tapestry of historical fact, educated guesswork
and engineering analyses. If successful, the
project would visualize the ship and provide
a guide to understanding a historically
important but largely unknown vessel type.
He found allies for the effort at Texas A&M’s
Visualization Sciences department, in
committee chairman Fred Parke and one
of his students, Audrey Wells.
A 3-D model of NOSSA
SENHORA DOS MÁRTIRES
was developed in Texas
A&M’s Visualization Lab
“The Visualization Lab here is one of the best
in the world, and working with them was a
very natural collaboration,” he says. “Audrey
and I would meet once a week; she would
ask questions, work on my hypotheses during
the week and email me JPEG files as she
progressed, which I would mark up and return;
then we would meet the next week and take
the process a step further. Every time we solved
one problem, we solved several – for example,
a space occupied by a capstan or a locker can’t
be occupied by something else. Every correct
solution reduces the number of possible correct
answers for other questions, making it all a very
exciting iterative process.”
The ship itself even lent a hand: the surviving
hull fragment carried carved construction
marks that helped the investigators to
reconstruct the hull shape and dimensions
with a good degree of certainty.
Dr. Filipe Castro,
Nautical Archaeology
Program,
Texas A&M University
Wells’ model developed over three years
and, as it progressed, drew in other students
and staff to help bring the project along. For
example, once the hullform was determined,
one naval engineering PhD candidate, under
the direction of Professor Nuno Fonseca,
built a scale model for towing tests while
another built a mesh model for analysis. The
Fall 2011 • Surveyor | 29
“For example, in one treatise there is a
paragraph describing how the people on
board stored their own cargoes, putting them
on the floor of their quarters,” he explains.
“They would build a little shelf on the wall
of the tiny little rooms where they would
sleep. Underneath that shelf they would
cram everything they could, considering
each voyage a once-in-a-lifetime opportunity
to become rich.”
Steps in the computer
modelling of the ship.
hull structure was built in Rhinoceros; the
outfitting, interior space arrangement and
cargo loading were done in Autodesk Maya;
and stability, performance and hydrodynamics
were analyzed using standard marine
engineering software developed at Lisbon’s
Instituto Superior Técnico.
Today, the model is ready and the team has
come up with a sound distribution of the
cargoes. Even the people on board have been
modeled, based on sketches by 16th-century
Italian painter Luca Cambiaso, although they
haven’t yet got the money to hire someone
who could put them inside.
Variation on the Design Spiral
As Castro describes it, the project became an
exciting variation on the idea of the design
spiral: a handful of hard evidence was built up
into an extensive, plausible model through
reasonable conjecture modified by the constant
addition of better information and much
repeated analysis. That said, the process wasn’t
without its bumps, as the historical record
sometimes offered very spare guidance.
“The naus we know of have many design
ideas in common, but they also incorporate
regional solutions that differed from builder
to builder – for example, in the connection
of the keel to the sternpost, or in the use of
vertical reinforcements to the upper hull.
The problem is that we don’t have a clear
picture that allows us to distinguish common
practices from one-time solutions. There’s also
a problem when it comes to recorded history,
in that we do not have one authoritative
document, but instead have a lot of little
passages and allusions, and one regulation.
As we developed the model I reviewed the
original data over and over, making sketches
and re-reading the papers again and again,
until I was able to develop a good idea of the
space distribution on board,” Castro says.
30 | Surveyor • Fall 2011
It was the human factor on board that gave
Castro his biggest surprise. “Records tell us
there were 450 people on board. I had no
idea how they all could fit. Looking at the old
contracts, I couldn’t imagine how I could cram
them into a ship with 220 tons of peppercorns,
other cargoes, guns, boxes, food and water in
barrels. When we were all done, I was amazed
to find that there were about 9 square feet of
space for every person on board.”
Overall, the vessel became a very interesting
subject for analysis, he says, particularly
because these ships were badly overloaded
when departing for home. “Naus were quite
crammed for the first month of the voyage and
the people had hardly room to move about,”
he says. “As they drank the first water, ate the
first chickens and so on, they started creating
space. Then it was a game of moving things to
maintain stability. In the end,” he says, “model
tests show our nau floats, handles well and is
pretty stable with 175 tons of ballast on board.”
The model performs, but not to all known
capabilities, so Nossa Senhora dos Mártires still
has some ways to go before any plans for a real
resurrection can be placed in the hands of a
shipwright. “We have built a very plausible
model, but would still like to do wind tunnel
tests to further calibrate it; for example, we
have not been able to make it sail against the
wind,” he says. “We have a group of diaries that
tell us how they sailed and in what direction,
so we know that these ships could sail against
the wind at about 12 degrees.”
Academia is sometimes likened to a snake
pit, but the many hands that helped bring
the old ship back to life attest to the power
of free-flowing knowledge. “We received
great help in our project from Texas A&M’s
Center for the Study of Digital Libraries, from
book collections at other universities and
are working closely with Fonseca’s team of
engineers at the Lisbon Technical University
to further refine the structure,” Castro says.
“The kind of collaboration we have received
shows the beauty of the university milieu.” ❖
A World Leader in Nautical
Archaeology, 90 Miles Inland
The excavated hull
remains of LA BELLE.
T
he resurrection of Nossa Senhora dos
Mártires is but one of many milestones
in the 35-year history of the Nautical
Archaeology Program at Texas A&M University.
Housed on Texas A&M’s College Station
campus, 90 miles north of Houston, the
Nautical Archaeology Program (NAP) was
established in 1976 through a collaboration
between the school and the Institute of
Nautical Archaeology (INA). Under the
agreement, the NAP would be part of
the Department of Anthropology, but INA
would be allowed to set its own admissions
standards and degree requirements and could
hire its own faculty. In addition, INA founders,
including pioneers of scientific nautical
archaeology George Bass and J. Richard
Steffy (deceased) for whom the NAP’s Ship
Reconstruction Laboratory is named, would
take turns teaching and leading students on
archaeological excavations.
“The university affiliation was perfect,
with INA serving as the field arm and Texas
A&M as the academic arm of a mutually
beneficial arrangement,” writes Bass on the
INA website (http://inadiscover.com/). “Over
the years, Texas A&M faculty have made the
university a world center for the conservation
of underwater archaeological finds, as shown
by its current conservation of La Salle’s ship
La Belle.”
Back in 2003, the State of Texas gave Texas
A&M the world’s biggest freeze-drier for
archaeological conservation. This unit has been
used to preserve the hull of the La Belle, which
will be displayed on a special titanium structure
designed by NAP researchers.
Over the past 35 years, the NAP-INA
collaboration has excavated some extremely
important sites, including the Uluburun
shipwreck in Turkey, dated to 1300 BC, which
disgorged 18,000 artifacts from many different
ancient cultures, and the Serçe Liman shipwreck
(also in Turkey), dated to 1025 AD, which
delivered, among many treasures, the world’s
largest single collection of medieval Islamic
glass, a large collection of Byzantine tools
and weapons and the earliest dated chess set.
“The curator of Islamic Art at the Metropolitan
Museum of Art in New York has written that
this excavation alone has revolutionized the
study of medieval Islamic art,” notes Bass. ◆
George Bass
J. Richard Steffy
Fall 2011 • Surveyor | 31
Bringing On Tomorrow
Ulf G. Ryder, CEO, Stena Bulk
The escavated hull
remains of LA BELLE.
he typical tanker of today reminds me
of a Volvo Amazon: a wonderful car,
still a pleasure to drive, but nonetheless
a vehicle of the past. There have been
refinements and modernizations over the
years, of course, but, apart from changes
in size, ‘modern’ tankers look much as they
did in the 1960s. In fact, you could say
that whole sectors of the maritime industry
are likewise old-fashioned or getting by
on old ideas. There isn’t a shortage of
creative minds, but a shortage of support
for innovation.
T
Yes, the industry is starting to react on fuel
economy, but that’s about all. From shipyards
to shipowners, there is precious little interest
in testing the borders of ship technology, in
putting resources on the line to go after a
revolution in ship design.
There are shipowners who sponsor a lot
of valuable innovation – Royal Caribbean
Cruise Lines comes to mind – but there
aren’t nearly enough of us. The shipowning
community has spent years getting rid
of its technical departments, relying on
classification for quality control and on
shipyards for innovation. The yards,
meanwhile, resist any innovation that
disrupts their production lines, and reject
real change in ship design even when it
comes to them.
Twelve years ago, the Stena V-Max brought
real innovation to tanker design: the draft
of a suezmax, the width of a ULCC and the
capacity of a VLCC, plus fully redundant
systems. But if the shipbuilding business
weren’t so bad at the time we might never
have found a yard willing to make the effort
to take on the project. Just last year, we
developed a 37,000-dwt tanker that, through
hullform alone, increases efficiency by 30
percent over typical designs – yet found
just one yard willing to build it. I can only
imagine what we’ll find when we go to build
an AirMax.
Ultimately, I believe a company’s record
regarding innovation reflects its management’s attitude towards people. After all,
innovation comes from listening to people’s
ideas. And, speaking as ‘management,’ I
32 | Surveyor • Fall 2011
can say it takes faith in your people and
trust in their abilities to bankroll an idea;
further, that it is necessary to find ideas worth
developing. Why? We’re not green fanatics,
but at Stena we do believe that, as responsible
citizens, we should try to leave our world a
little better than we found it. It is important
to help technical evolution advance because
it adds value to society at large.
It takes many hands to bring on tomorrow:
people with good ideas, people to share the
effort and, most importantly, people to fund
the research. When you are willing to ‘waste’
money following an idea, you give people
the opportunity to develop something really
special. Technology aside, that attitude of
trust and respect helps develop something
even more important.
As people, we are all instructed and
affected by the environment in which we
work. I saw the effects of bad management
when I worked at a company named
Broströms as a young man; there was little
recognition for the employees and little
interest in their ideas. It was a gloomy place
where the top executives sat in huge offices
and floated royally above everyone else, who
felt invisible to them. If I had stayed there,
I might have ended up believing that that
is the way to run a company.
Fortunately, I came to Stena and was raised
in an environment where the guys at the
top ‘see’ their employees and recognize their
efforts. They helped me better myself, and
together we help the rest of the people do the
same. I am proud that my division has brought
up good, productive and satisfied employees
all over the world. You can only achieve that
if you are interested in people.
Is it worth it to care? Consider this: the
Broströms I knew has been broken up and
bought, while Stena keeps going, like an
IKEA of the sea.
Whether it’s technical innovation or
corporate success, it is all about people.
Individually, we have limited power, but
together we can jump over houses and
move mountains – and that is the name
of the game. ❖
“T
he lightest type of
efficiency is that which
can utilize existing
material to the best
advantage.”
– Jawaharlal Nehru
1889 - 1964
TX 11177 7/11 12500