1. Canadian Journal on Environmental, Construction and Civil Engineering Vol. 2, No. 5, June 2011
Environmental Risk Compliance for Nature Gas
Ship Design and Operation
O.O. Sulaiman, A.H. Saharuddin, A.S.A. Kader, W.B.Wan Nik
Abstract — The quests for an efficient fuel friendly to the The drive towards environmentally friendlier fuels points next
environment have been recognized in maritime industry for a to Natural Gas (NG) and the infrastructures to support that
long time through improvements of gasoline and diesel by trend are being pre-positioned by corporate mechanisms as
chemical reformulation. Inconvenience posed by these well as governmental bodies worldwide. NG is cheap and its
reformulation chemicals is performance problems; cold-start reserve is plentiful. Natural Gas as fuel is becoming more and
ability, smooth operation and avoidance of vapor lock. more established in urban transport and Power Generation
Climate change problem has further aggravated need to use sectors. Its use will also take aggressive approach for all inland
fuel that could contribute to decrease in green house gases vessel including ferries in the eyes of potential environmental
and ozone-forming pollutants. Alternative fuels to petroleum compliance new regulations. Internationally its operational
have been identified to include, compressed natural gas record and GHG gas score is rated as GOOD. However, CNG,
(CNG); liquefied petroleum gas (LPG); methanol from natural LPG and ethanol has been proven to be environmental friendly
gas LNG. Selection of this towards centralized reduction of and has fuel economy of 50 percent. This shows that, CNG
Green House Gases (GHGs) will depend on ease of use, and LPG have potential for large market for use in niche
performance and cost. LNG cargo is conditioned for long markets in both developed and developing countries. Other
distance transfer while CNG and LPG cargo are conditioned gains from CNG and LPG depend on the amount of associated
for end user consumption and short distance transfer. It is methane emissions from gas recovery, transmission,
therefore, clear that promoting the use of CNG will catalyze distribution, and use. On a full-cycle basis, use of LPG can
boosting of economy of coastal ship building and result in 20-25% reduction in GHG emissions as compared to
transportation, including environmental friendly utility fuel, petrol, while emission benefits from CNG are smaller - about
and new generation of intermodal transportation and supply 15%. [1]
chain. Since the danger behind use of this gas could not be
either underestimated by virtue regarding coastal operation Furthermore, it is clear that promoting the use of CNG and
proximity and consequence. The paper will discuss risk and LPG will be a catalyst to boost economy of coastal ship
potential regulation that will formulate beyond compliance, building, environmental friendly intermodal transportation for
decision towards use of top - down risk based design and supply chain.. Efficient and reliable operation can be made
operations that will reinforce new integrative, efficient, afforded by LPG, transportation, supply vessel, tugs to support
environmental friendly, reliable multimodal and intermodal this potential development. On the regulatory regime, IMO
links advanced concepts for LPG ship operating in coastal focus more on operational issues relating to carriage of gas
and restricted waters. with no specification for CNG and LPG, while the ICG code
and class society guidelines elaborate on the design as well as
operational consideration. Local administration imposes
Key Words — NG, LNG, CNG, LPG, HAZOP, penilaian additional regulation as required for their respective
risiko, Terusan, Rekaan berdasarkan Risiko dan implementation.
matlamat, Persekitaran, Tenaga
Time has revealed that there will be large demands for these
I. INTRODUCTION gases. This paper focus on integrative use of IMO prescriptive
goal and risk based standards with holistic consideration of
Fuel technology has been dominated with ways to improve factors require for safe design and operation of LPG ships in
gasoline and diesel by chemical reformulation that can lead inland water. Including hybrid use of elements of Formal
increase efficiency and additional inconvenience leading to Safety Assessment (FSA) and Goal Based Standards (GBS) to
ozone depletion, green house and acid rain forming pollutants. prevent, minimize control and guarantee the life span of LPG
Likewise, side effects problems posed to transportation ships and protection of environment. The paper will discussed
vehicles have been dominated by condition, other performance top down environmental risk generic risk model and
issues. Time has shown that the global trend in de- operations of LPG ship. It will describe the characteristics of
Carbonization of the energy system follow the following path: LPG, regulatory issues and environmental issues driving
COAL > OIL> NATURAL GAS > HYDROGEN today’s beyond compliance and selection of new technology
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2. Canadian Journal on Environmental, Construction and Civil Engineering Vol. 2, No. 5, June 2011
policy. Since it is the consequence of accident and incident A. Transportation of Gas - The best place to install the plant is
that leads to environment disaster, the paper will discussed near the gas source. The gas is basically transported through
issues that allow prevention and control of accident. Since pipelines or by truck and barge.
issues relating to global warming, GHG releases is strictly
linked to ship energy source, the paper will also discuss impact B. Pretreatment of Gas- The liquefaction process requires that
areas and potential new technology driving beyond compliance all components that solidify at liquefaction temperatures must
policy adoption for LPG design and operation. be removed prior to liquefaction. This step refers of treatment
the gas requires to make it liquefiable including compression,
O.O. Sulaiman is with the University Malaysia Terengganu, Faculty filtering of solids, removal of liquids and gases that would
of Maritime Studies and Marine Science, 21030, Kuala solidify under liquefaction, and purification which is removal
Terengganu,Terengganu, Malaysia (e-mail: o.sulaiman@umt.edu.my).
A.H. Saharuddin is with the University Malaysia Terengganu,
of non-methane gases.
Faculty of Maritime Studies and Marine Science, 21030, Kuala
Terengganu,Terengganu, Malaysia (e-mail: sdin@umt.edu.my. C. Liquefaction of Gas - Today, alternative fuels to petroleum
W.B. Wan Nik is with the University Malaysia Terengganu, Faculty has been identified to include Compressed Natural Gas
of Maritime Studies and Marine Science, 21030, Kuala (CNG); Liquefied Petroleum Gas (LPG); methanol from
Terengganu,Terengganu, Malaysia (e-mail: niksani@umt.edu.my.
A.S.A Kader is with the University Technology Malaysia, Faculty of
natural gas, coal or biomass; ethanol from biomass; electricity
Mechanicak Engineering, Johor Bahru, Skudai, Malaysia (e-mail: and hydrogen. However NG quality may be expressed with the
absaman@fkm.utm.my. Wobbe Index - Methane Number MN80 (Volume percent
hydrogen atoms / carbon atoms) or Methane >=88%
Since 1960s, CNG and LPG are recognized as vehicle fuel
II. NATURAL GAS AND ITS PRODUCTS alternative to oil-based gasoline and diesel fuel that reduces
pollution of the air. It is a natural gas compressed to a volume
Natural gas in its liquid state (LNG) or liquid natural gas and density that is practical as a portable fuel supply.
that comprise of liquid hydrocarbons that are recovered from Compressed natural gas (CNG) and Liquefies petroleum gas
natural gases in gas processing plants, and in some cases, from (LPG) are use as consumer fuel for vehicles, cooking food and
field processing facilities. These hydrocarbons involve heat homes. There exist a vast number of natural gas
propane, pentanes, ethane, butane and some other heavy liquefaction plants designs, but, all are based on the
elements. LNG accounts for about 4% of natural gas combination of heat exchanger and refrigeration. The gas
consumption worldwide, and is produced in dozens of large- being liquefied, however, takes the same liquefaction path.
scale liquefaction plants. Natural gas contains less carbon than The dry, clean gas enters a heat exchanger and exits as LNG.
any other fossil fuel and, therefore produces less carbon The capital invested in a plant and the operating cost of any
Dioxide (CO2) when compared to any conventional vehicles. liquefaction plant is based on the refrigeration techniques.
Its usage also results in significantly less carbon monoxide
(CO), as well as less combustive organic compounds than their Natural gas is transported through pipelines to refuelling
gasoline counterparts. It is produced by cooling natural gas to stations then compressed at a pressure of 3,000 psi with the
a temperature of minus 260 degrees F (minus 160 Celsius). At help of specially installed compressors that enables it to be
this temperature, natural gas becomes liquid and its volume loaded as gas cylinders for vehicles.
reduces 615 times. LNG has high energy density, which makes The process consists of drawing the natural gas from
it useful for energy storage in double-walled, vacuum-insulated underground pipelines by the compressor. The composition of
tanks as well as transoceanic transportation. pipeline natural gas varies considerably depending on the time
of year, pipeline demand, and pipeline system. It may contain
The production process of LNG starts with Natural Gas, impurities, like oil, particulates, hydrogen sulphide, oxygen or
being transported to the LNG Plant site as feedstock, after water. Hence, the modern day, quality LPG plant system
filtration and metering in the feedstock reception facility, the consists of facilities to address these problems. Using LNG as
feedstock gas enters the LNG plant and is distributed among the feedstock to make CNG and LPG eliminates or mitigates
the identical liquefaction systems. Each LNG process plant each of the above stated concerns as contains no water or any
consists of reception, acid gas removal, dehydration removal, such impurity. This eliminates the concerns for corrosion,
mercury removal, gas chilling and liquefaction, refrigeration, plugging of fuel lines, and the formation of hydrates.
fractionation, nitrogen rejection and sulfur recovery units. LPG Significant design innovation will involve development
and CNG are made by compressing purified natural gas, then of liquefied gas technology that promises lower costs and
stored and distributed in hard containers. Mostly, LPG station shorter scheduling time than either Liquefied Natural Gas
is created by connecting a fuel compressor to the nearest technology or a pipeline transport as well as provision of
natural gas pipeline distribution system. The process through unique solution to the development of distressed or stranded
which Liquefied Natural Gas is produced consists of tree main gas reserves and alternative to associated gas re-injection.
steps, namely:- Liquefied Petroleum Gas (LPG) can also be produced either as
a by-product when refining crude oil or direct from the gas
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3. Canadian Journal on Environmental, Construction and Civil Engineering Vol. 2, No. 5, June 2011
wells. The two most common LPG gases are known as 42.4% of the density of air and thus is lighter and may
Commercial Propane and Commercial Butane as defined in BS disappear in case of leakages.
4250 [2]
Up to 15kg and generally used for leisure applications and IV. 4. NATURAL GAS AND LPG
mobile heaters. Commercial Propane is predominately stored
in red cylinders and bulk storage vessels and especially used LG carriers has proven considerable good safe ship in term
for heating, cooking and numerous commercial and industrial of designed, constructed, maintained, manned and operated of
applications. LPG has one key characteristic that distinguishes all the merchant fleet of today. So far they have low accident
it from Natural Gas. Under modest pressure LPG gas vapor record and non major has lead to release of large amounts of
becomes a liquid. This makes it easy to be stored and LG have ever occurred in the history of LG shipping.
transported in specially constructed vessels and cylinders. The Nevertheless, there have been major concerns regarding safety
combustion of LPG produces Carbon Dioxide (CO2) and water of LG shipping and vivid that one catastrophic accident has the
vapor therefore sufficient air must be available for appliances potential for serious consequential fatal and environmental
to burn efficiently. Inadequate appliance and ventilation can damage. Therefore it became imperative to use IMO Goal -
result in the production of toxic Carbon Monoxide (CO). All based and risk based instruments to quantify a baseline risk
things being equal, it produces much less hydrocarbon level to identify and evaluate alternative risk control options
compare to diesel. Hazards associated with LPG ships are for improved safety. Toward zero accident and zero, incident,
linked to the gas characteristics that attract beyond apart from normal SOLAS standards for all ships, there are
compliances operability and design policy. Selection of this additional international regulation / Code for the Construction
towards centralized reduction of GHGs will depend on ease of and Equipment of Ships Carrying Liquefied Gases in Bulk this
use, performance and cost. include- The IGC Code. This Code is applicable to Liquefy
gas carriers which are made mandatory under the SOLAS
III. . NATURAL GAS PROPERTIES Convention. Thus, Risks associated with
LPG ships encompass the following
Everyone dealing with the storage and handling of LPG areas:
should be familiar with the key characteristics and potential
hazards. Matter either in their solid, a liquid or a gaseous form i. loading
is made from atoms which combine with other atoms to form ii. shipping in special purpose vessels
molecules. Air is a gas, in any gas, large numbers of molecules iii. Unloading at the receiving terminal.
are weakly attracted to each other and are free to move about iv. Third party risks to people onshore or onboard
in space. A gas does not have a fixed shape or size. Each gas
that the air is composed of consists of various different NG shipping industry is undergoing considerable changes,
properties that add to the overall characteristics of a particular e.g. an expected doubling of the fleet over a 10-year period,
gas.[3] Gases have certain physical and chemical properties emergence of considerable larger vessels, alternative
that help to differentiate a particular gas in the atmosphere. propulsion systems, new operators with less experience new
Depending on different properties the gases are used widely in trading route, offshore operations and an anticipated shortage
several applications. Below are some of the gases properties - of qualified and well trained crew to man Liquefies gas
Natural gas may consist of: carriers in the near future.
i. Methane CH4 -> .80%
ii. Ethane C2H6 ->.20% With this development, there is tendency for gas shipping to
iii. Propane C3H8 ->20% experience an increasing risk level in the time to come.
iv. Butane C4H10 ->20% Most IMO previous rules were made on reaction basis, in
v. Carbon Dioxide CO2->.8% this age of knowledge employment of the new philosophy to
vi. Oxygen O2 ->0.2% design construct and operate based on risk and considering
vii. Nitrogen N2 ->5% holistic factors of concern for sustainability and reliability
viii. Hydrogen sulphide H2S ->5% remain a great invention of our time to save LPG ship and
ix. Rare gases-> A, He, Ne, Xe trace shipping.
Hazards associated with LPG ships are linked to the gas
characteristics and beyond compliances operability and design. V. MARITIME REGULATION
CNG are a non toxic gas liquid at -259 °F / -162 °C which
ignites at 1350°F / 732°C. The octane number is 120; it can The International convention for the Safety of Life at Sea
inflame having a share of 5.3 to 15% in air. Methane has only (SOLAS) is the fundamental IMO instrument that deal with
regulation requirement for basic construction and management
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4. Canadian Journal on Environmental, Construction and Civil Engineering Vol. 2, No. 5, June 2011
for all types of ships. It covers areas like are stability,
machinery, electrical installations, fire protection, detection The code specifies the ship survival capability and the
and extinction systems, life-saving appliances, Surveys and location of cargo tanks. According to the type of cargo, a
inspections, SOLAS also contains a number of other codes minimum distance of the cargo tanks from the ship’s shell
related to safety and security that applies to shipping in plating is stipulated in order to protect the cargo in case of
general. Examples of these are the Fire Safety Systems Code contact, collision or grounding events. Thus the code
(FSS Code), the International Management Code for the Safe prescribes requirements for ships carrying different types of
Operations of Ships and for Pollution Prevention (ISM Code) liquefied gas, and defines four different standards of ships, as
and the International Ship and Port Facility security Code described in Table 1. LNG carriers are required to be ships of
(ISPS Code). These codes imply requirements aiming at type 2G and all LNG carriers should be designed with double
enhancing the safety on Liquefy Gas (LG) shipping activities hull and double bottom, while 2PG type is for LPG Ships.
as well as shipping in general [4, 5]
Classification society rules apply for structural strength TABLE 1
while special code for ships carrying liquefied gas included in REQUIREMENT FOR SHIP CARRYING LIQUEFIED
the SOLAS regulations- the IGC code. Other IMO regulations GAS
pertaining to safety are contained in the International Ship Cargo
convention on Load Lines which addresses the limits to which type
a ship may be loaded, the International Convention for the 3G Require moderate prevention method
Prevention of Collisions at Sea (COLREG) addressing issues 2G Ship less than 150m Require significant
related to steering, lights and signals and the International preventive measure
Convention on Standards of Training, Certification and Watch 2PG Require significant preventive measure
keeping for Seafarers (STCW Convention) which addresses cargo are carried in C tanks
issues related to the training of crew. The International 1G Require significant maximum preventive
Convention for the Prevention of Pollution from Ships measure
(MARPOL) addresses issues related to marine and air
pollution from ships. These regulations are applicable to all
ships as well as LPG ships. The issue of global warming has The IGC code requires segregation of cargo tanks and cargo
initiated MARPOL annex VI, was given preferential vapor piping systems from other areas of the ship such as
acceptance beyond tacit procedure and there is indication that machinery spaces, accommodation spaces, control stations; it
more will follow [6] also prescribes standards for such segregation. It provides
standards for cargo control rooms and cargo pump-rooms are
VI. MARITIME REGULATIONS FOR LIQUIFY GAS as well as standards for access to cargo spaces and airlocks. It
REGULATION defines requirements for leakage detection systems, as well as
loading and unloading arrangements. Different types of cargo
IMO regulation for safety regarding carriage of gas was containment systems are permitted by the IGC code, and the
never specifically for LNG, CNG or LPG carriers. However two main types of containment systems in use in the world
safety regulations exist in order to ensure the LPG ships are liquefied tanker fleet are membrane tanks and independent
safe. Thus Gas carriers need to comply with a number of tanks. Membrane tanks are tanks which consist of a thin layer
different rules that are common to all ship types, as well as a or membrane, supported through insulation by the adjacent
set of safety regulations particularly developed for ships hull structure. The membrane should be designed in such a
carrying liquefied gas and the their crew as well as site way that thermal expansion or contraction does not cause
selection and design of LG terminals. This include issues undue stress to the membrane. The independent tanks are self-
relating to control of traffic near ports, local topology, weather supporting in that they do not form a part of the ship’s hull.
conditions, safe mooring possibility, tug capability, safe [10]
distances and surrounding industry, population and training of
terminal staff. These considerations contribute to enhance the The IGC code defines three categories of independent tanks:
safety of LPG shipping in its most critical phase, i.e. sailing in Type A, B and C. Type C tanks are pressure tanks for LPG
restricted waters or around terminal and port areas. and will not be required for LNG vessels since LNG are
transported at ambient pressure. Regardless of what
The IGC code prescribes a set of requirements pertaining to containment system is used, the tanks should be design taking
safety related to the design, construction, equipment and factors such as internal and external pressure, dynamic loads
operation of ships involved in carriage of liquefied gases in due to the motions of the ship, thermal loads, sloshing loads
bulk. The IACS unified requirements for gas tankers were into account, and structural analyses should be carried out. A
partly derived from the IGC code. separate secondary barrier is normally required for the gas
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5. Canadian Journal on Environmental, Construction and Civil Engineering Vol. 2, No. 5, June 2011
liquefied gas containment systems to act as a temporary 95, ISM code, tanker familiarization training, as well as flag
containment of any leakage of LNG through the primary state or company specific training requirements that go beyond
barrier. For membrane tanks and independent type a tanks, a these international regulations [12, 13]
complete secondary barrier is required. For independent type
B tanks, a partial secondary barrier is required, whereas no
The competence level of Liquefied gas crew has generally
secondary barrier is required for independent type C tanks.
been regarded as quite high compared to that of other ship
The secondary barrier should prevent lowering of the
types. A study presented in demonstrates that the performance
temperature of the ship structure in case of leakage of the
score of crew onboard gas and chemical tankers are the best
primary barrier and should be capable of containing any
among cargo carrying ships, second only to that of passenger
leakage for a period of 15 days.
vessels. STCW 95 contains minimum training requirements for
crew engaged in international maritime trade. In particular,
The code contains operational requirements related to i.e.
chapter V of the STCW code contains standards regarding
cargo transfer methods, filling limits for tanks and the use of
special training requirements for personnel on certain types of
cargo boil-offs as fuel as well as requirements on surveys and
ships, among them liquefied gas carriers. One requirement for
certification. Equivalents to the various requirements in the
masters, Officers and ratings assigned specific duties and
code are accepted if it can be proven, e.g. by trials, to be as
responsibilities related to cargo or cargo equipment on all
effective as what is required by the code. This applies to
types of tankers, e.g. LNG tankers, is that they shall have
fittings, materials, appliances, apparatuses, Equipments,
completed an approved tanker familiarization course. Such a
arrangements, procedures. Additional requirements regarding
course should have minimum cover the following topics:
insulation and materials used for the cargo containment
systems as well as construction and testing, piping and valving
i. • Characteristics of cargoes and cargo toxicity
etc. are included in the IGC code. The IGC code also requires
ii. • Hazards and Hazard control
certain safety equipments to be carried onboard LPG carriers.
iii. • Safety equipment and protection of personnel
These include ship handling systems such as positioning
iv. • Pollution prevention
systems, approach velocity meters, automatic mooring line
monitoring and cargo handling systems such as emergency
The course must provide the theoretical and practical
shutdown systems (ESD) and emergency release system
knowledge of subjects required in further specialized tanker
(ERS). In addition, systems for vapor, fire detection, fire
training. Specialized training for liquefied gas tankers should
extinguishing (dry chemical powder) and temperature control
as a minimum include the following syllabus:
are required.
i. • Regulations and codes of practice
In addition to the numerous regulations, codes,
ii. • Advanced fire fighting techniques and tactics
recommendations and guidelines regarding gas carriers issued
iii. • Basic chemistry and physics related to the safe
by IMO, there are extensive regulations, recommendation and
carriage of liquefied gases in bulk
guidelines under international and local umbrella related to
iv. • Health hazards relevant to the carriage of liquefied
safety LPG shipping exist that undoubtedly contributing to the
gas
high safety standard and the good safety record that has been
v. • Principles of cargo containment systems and Cargo-
experienced for the fleet of LG carriers. e.g. standards of best
handling systems
practice issued by SIGTTO (The Society of International Gas
vi. • Ship operating procedures including loading and
Tanker & Terminal Operators) [4, 11]
discharging preparation and procedures
vii. • Safety practices and equipment
viii. • Emergency procedures and environmental
VII. TRANING REQUIREMENT protection
Any person responsible for, or involved with, the operation
and dispensing of LPG should have an understanding of the In addition to these training requirements, masters, chief
physical characteristics of the product and be trained in the engineering officers, chief mates, second engineering officers
operation of all ancillary equipment. Thus acquiring sufficient and any persons with immediate responsibilities for loading,
crew with the required level of experience, training and discharging and care in transit of handling of cargo in a LG
knowledge of LG are believed to be one of the major safety- tanker are required to have at least 3 months sea service on a
related challenges to the maritime LG industry in the years to liquefied gas tanker. Due to the extensive training
come. In addition to strict regulations on the ship itself, there requirements and experience level of their personnel, the
are also extensive international regulations specifying the maritime LNG industry claims that the crew sailing the LNG
necessary training and experience of crew that operate LPG fleet are among the best in the world. However, a shortage of
carriers. These include the international rules on training experienced LG crew is foreseen in the near future especially
requirements are contained in regulations such as the STCW with the expected growth of the LPG fleet.
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6. Canadian Journal on Environmental, Construction and Civil Engineering Vol. 2, No. 5, June 2011
VIII. TRANSPORTATION OF LPG INIAND WATER Ship Concept design - is very important in shipping and it
account for 80 percent of failure, therefore compliance and
making of optimal design has a great impact in ship whole life
cycle. The impact of environment in ship design is very
LPG and CNG and LNG are next in line of alterative for difficult because of large numbers of uncertainties.
transportation to gasoline because of their associated Environmental impact hat need to be taken into considerations
environmental benefits including reduction of GHGs. Thus, it in concept design can be classified into the following:
is more useful for countries with natural gas resources and a Operations: considering limiting life cycle of ships at estimate
relatively good gas distribution system. LPG has been of 25 years, issues relating to the following are equally not
explored in the 1930s but its used has been slowed because of easy to quantify in design work, even thus a lot of research
favorable economy of petroleum. However, the current threat effort has been set on move on this, but the call of the day
of climate change has increased the focus on alternative require allowable clearance and solution to be given to the
transport fuels which include. Countries with programmes on following: Known emission, Accidental, Ballast waste,
the use of CNG and LPG as a transport fuel include the USA, Coating
Canada, UK, Thailand, New Zealand, Argentina and Pakistan Commercial forces: where company that or product that
[1,2] CNG and LPG are used in both private vehicles and operate in unenvironmental friendly way, people are prone to
transport fleets. It is estimated that about 250 million vehicles spurn the companies products and service, there fore having
are using this fuel worldwide, and its use is on the increase, impact on company return on investment.
representing 2% of total global transport fuel use. The
Construction and Disposal- use of meticulous scantling and
advantages of using LPG are:
factors worth consideration with the ship at the end of her life
i. Environmental friendliness cycle
ii. reduced engine maintenance cost
Shipboard environmental protection should Pollution
iii. Improved engine and fuel efficiency
Prevention (P2) or Pollution Control. Pollution Prevention
Use fewer environmentally harmful substances and generate
However limitations are the following:
less waste on board. Pollution Control: Increase treatment,
i. Storage containment
processing, or destruction of wastes on board. The basic P2
ii. High cost of conversion
principles follow: Eliminating the use of environmentally
iii. Need for high skill operator
harmful chemicals and reducing the amount of waste we
generate on board is often better that treating it on board.
Each category of this required thorough, holistic risk, goal
Typical environmental green house gas release from different
based design and operability assessment for safety, reliability
prime movers is shown in Table 2.
and protection of environment
5.1 Environmental concern- a driving force for beyond
compliance policy
TABLE 2
Over the last decade, each passing years has been
augmented concerned about issue of environment importance ENVIRONMENTAL PERFORMANCE
in design, construction, operation and beneficial disposal of EMISSION LPG GASOLINE DIESEL
marine articraft .the overriding force is increasing the COx 1 10.4 1.2
resources of the planet that we live and that only a few are HC 1 2.0 1.2
renewable. This accumulated to production that has elements
NO 1 1.2 1.1
of long-term sustainability of the earth. Precipitated effect over
PM neg present Very high
the year has call for public awareness and translated into
SOx neg neg Very high
impact through these the following manners:
Regulations: public pressure on governmental and non- Emission is inherent consequence of powered shipping, Fuel
governmental organization regulation due to untold stories of oil burning as main source, Continuous combustion
disaster and impact, the public is very concerned and in need machineries - boilers, gas turbines and incinerators. And this
of fact that if the quality of life of people enjoy is to be made the following issue very important:
sustained, for them and the future generation then the
environment must be protected. conspicuous issue, expertise i. Worldwide focus of fuel-> Exhaust gas emission law
and finding of regulations make them to go extra length on by IMO and introduction of local rules
unseen issue, contrasting between the two, while commercial ii. Emission limits driving evolution to development and
force act on hat will be forth problems. adaptation to new technology
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7. Canadian Journal on Environmental, Construction and Civil Engineering Vol. 2, No. 5, June 2011
iii. Solution anticipated to maintenance of ship life cycle Towards sustainable reliability, it is preferable to use
at average of 25 years stochastic and probabilistic methods that could help improve
iv. Focus is currently more on, NOx and SOx – HC, COx in the existing methodology this method involve absolutism
and particulate will soon join that will cover all uncertainty complimented by historical and
v. Consideration involves not only fuel use and design holistic matrix investigation. Hybridizing models is also a plus
but also operational issues. for the best solution of sustainable maintenance of navigation
channel. Beyond compliance towards meeting required safety
level and life cycle and environmental protection required
Table 3 below shows the environmental regulatory demand of systematic employment of hybrid of OBS and RBS systems.
out time for ships that need to be considered
Below is the general step of RBS and OBS which can be
in design and operation of LPG ships.
apply for above described characteristic of LPG Ships.
TABLE 3
ENVIRONMENTAL DEMAND FOR SHIPS X. COMPONENTS OF GOAL BASED STANDARDS
Environme Environmental Demand
ntal
parameters
Ship
design
Need for longer safe life cycle Objective -based standards (OBS) are ship safety standards
comprising five tiers (see Figure 1):
Constructi
on
High worker safety standards, Low energy
input
Level I, consists of goals expressed in terms of safety
Emission Minimum pollution and emission, objectives defined by risk level.
Minimum Sox, Nox and Cox, PMs-Zero
discharge Level II, consists of requirements for ship
Scrapping Zero harmful emission
Operations Efficient maneuverability
features/capabilities, defined by risk level, that assure
waste,
Energy Maximum fuel efficiency
achievement of ship’s safety objectives.
Antifoulin
g
Harmless LEVEL III, here Tier IV and V are to be verified for
Ballast
water
Zero biological invasion or transfer of
alien species
compliance with Tier II.
Sea
mammal
Maneuverability capability Level IV, consists of rules, guidelines, technical procedures
Interaction and programs, and other regulations for ship designing and
Accident Able officer, Ship structure, Integrity
ship operation needs, fulfillment of which satisfies ship’s
Fire Harmless
Wave
feature/capability requirements.
wash of
High speed
Zero inundation and spray ashore Level V, consists of the code of practice, safety and quality
Marine
craft
systems that are to be applied to guarantee the specified rules
by quality level.
IX. .HYBRID USE OF HIGH LEVEL OBJECTIVE BASED AND
SAFETY RISK BASED DESIGN TOWARDS BEYOND
COMPLIANCE
It is clear that the shipping industry is overkilled with rules
and recent environmental issues are have potential to initiate
new rules, this made firms to selectively adopt “ beyond
compliance “ policy that are more stringent than the required
extant law due to . Beyond compliance policy are mostly intra
– firm process – which could be power based or leadership
based. it draw insight from institutional theory, cooperate
social performance perspective, and stakeholder theory that
relate to internal dynamic process. While external forces create
expectation and incentive for manager, intra firm politics
influence how managers perceive, interpret external pressure
and act on them [7, 14] Policy towards beyond compliance fall
into 2 categories:
i. Whether they are now required by law but they are
consistent with profit maximization.
ii. Requirement by law and firm are expected to comply
by them.
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8. Canadian Journal on Environmental, Construction and Civil Engineering Vol. 2, No. 5, June 2011
RISK = Hazard x Exposure (an estimate on probability that
High level Goal Assessment certain toxicity will be realized). While HAZARD: Anything
-Standards Requirement Level that can cause harm (e.g. chemicals, electricity, natural
- Functional Requirement 1&2 disasters)
Severity may be measured by:
Analysis
Goal
Compliance
i. No. of people affected
Level 3
ii. Monetary loss
iii. Equipment downtime
IMO Instruments Level
iv. Area affected
Class Guides 4&5
v. Nature of credible accident
process
Design
process
Approval
Risk ranking index according to level of risk the tables bellow
show an example of risk matrix (Table 4) with assignments of
risk level identifies by number index.
Secondary standards Table 4: Risk level matrix
-for company or individual Consequence Criteria
1 2 3 4 5
ships Insignificant Minor Moderate Major Catastrophic
The consequence is almost Very
Very High
Fig. 1: High level Goal Based Assessment A- certain to occur in most Medium (M) High (H) High (H) High
(VH)
circumstances (VH)
The consequence is likely to Medium High Very High
B- Medium (M) High (H)
occur frequently (M) (H) (VH)
Possible and likely for the
Medium High
C- consequence to occur at some Low (L) High (H) High (H)
(M) (H)
A. Sustainable Risk Assessment time
The consequence is unlikely to Medium Medium
D- Low (L) Low (L) High (H)
Sustainability remain a substantial part of assessing risk and occur but could happen (M) (M)
The consequence may occur
life cycle of ships– however, they are very complex and
Likelihood
Medium Medium
E- but only in exceptional Low (L) Low (L) High (H)
require long time data for accurate. Environmental risk and circumstances
(M) (M)
Environmental impact assessment (EIA) procedure is laid out
by various environmental departments and will continue to
remain similar except that the components of risk area cover Risk management is the evaluation of alternative risk
different uncertainty to sustain a particular system are reduction measures and the implementation of those that
different. EIA has been a conventional process to identify, appear cost effective where Zero discharge = zero risk, but the
predict, assess, estimate and communicate the future state of challenge is to bring the risk to acceptable level and at the
the environment, with and without the development in order to same time, derive the max Benefit [10]
advise the decision makers the potential environmental effects
of the proposed course of action before a decision is made.
RBS is improvised version of EIA where holistic
consideration, community participation, expert rating, cost
XI. COMPONENTS OF SYSTEM BASED SAFETY RISK
benefit analysis and regulatory concerned are core part of the
ASSESSMENT
philosophy leading to reliable decision making and sustainable
system design and operation. In risk assessment, serenity and
probability of adverse consequence (HAZARD) are deal with System based safety assessment targets:
through systematic process that quantitatively measure ,
perceive risk and value of ship using input from all i. Iidentification of potential hazard scenarios and
concerned- waterway users and experts [8, 14] major impact to ship Shipping and ship design which
could lead to significant safety or operability
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9. Canadian Journal on Environmental, Construction and Civil Engineering Vol. 2, No. 5, June 2011
consequences as well recent call for policies chance The risk analysis (step 2) comprises a thorough
and procedural major effects investigation of accident statistics for liquefy gas carriers as
ii. Verification of current design, construction and well as risk modeling utilizing event tree methodologies for the
operations ensure that risk from identified scenarios most important accident scenarios, based on the survey of
meet risk acceptability criteria accident statistics and the outcome of the HAZID leading to
iii. If not, to recommend additional RBA process and generic accident scenarios recommendation for further risk
available technology for control and protection that analysis. Figure 2 shows formal safety assessment steps.
can reduce risk to suitable level.
Bellow is the general RBA steps:
Step 5
Step 1 Step 2 desision
Step 3 Step 4
Hazard Risk and
Optiions Cost
RBA STEPS: identification Analysis2
Control Benefit recommendatio
n
STEP 1 - HAZID:
The HAZID (step 1) should be conducted a in a technical
meeting including brainstorming sessions, from various sectors
within the LPG industry, i.e. ship owner/operator, shipyard,
ship design office/maritime engineering consultancy,
Fig. 2: Risk assessment and analysis steps
equipment manufacturer, classification society and research
centre/university.
The risk analysis essentially contains two parts, i.e. a
frequency assessment and a consequence assessment. The
Common identifiable hazards are:
frequency assessment, involve estimation of frequency of
generic incidents using reasonable accident statistics derived
i. Emission to air, water and soil
from the selected accident scenarios which should also be
ii. Shipboard cargo tank and cargo handling equipment
compared with similar studies for liquefy gas carriers as well
iii. Storage of tanks and Piping
as other ship. The consequence assessment should be
iv. Safety Equipments and Instruments
performed using event tree methodologies. Risk models can be
v. Ruder failure in inland water
developed for each accident scenario and event trees
vi. Crew fall or slip on board
constructed according to these risk models utilizing accident
vii. Fault of navigation equipments in inland water
statistics, damage statistics, fleet statistics, simple calculations
viii. Steering and propulsion failure
modeling and expert opinion elicitation [15]
ix. Collision with ship including Passing vessel hydro
dynamic effects
The frequency and consequence assessments provide the
x. Terrorist attack or intentional incident
risk associated with the different generic accident scenarios
xi. Potential Shortage of crew
which can be summarized in order to estimate the individual
xii. Navigation and berthing procedure
and societal risks pertaining to liquefy gas carrier operations
and design. Based on available accident statistics and results
The results from the HAZID should be recorded in a risk
from the HAZID, eight generic accident scenario umbrellas
register stating total number of hazards, different operational
that required deep analysis are:
categories. The top ranked hazards according to the outcome
of the HAZID can be selected and given respective risk index
i. Collision
based on qualitative judgment by the HAZID participants from
ii. Fire or explosion
diverse field of expert. It should emphasize on the study of
iii. Grounding
existing situations and regulations including policies in place,
iv. Contacts
present performance, flaws and survey on parties feeling on
v. Heavy weather/loss of intact stability
acceptability and procedures.
vi. Failure/leakage of the cargo containment system
vii. Incidents while loading or unloading cargo LPG
STEP 2 - Hazard analysis viii. Emission ship power sources
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10. Canadian Journal on Environmental, Construction and Civil Engineering Vol. 2, No. 5, June 2011
The first five generic accident scenarios are general in the ii. Grouping of the measures into possible risk control
sense that they involve all types of ships; wile 6 and 7 accident options using
scenarios are specific to gas carriers and 8 concerned new a. -General approach- which provides risk
environmental issue driving compliance and technology for all control by controlling the likelihood of
ships. Selected accident scenarios to investigate frequency initiation of accidents, and may be effective
assessment could provide a sufficiently accurate estimate of in preventing several different accident
initiating frequencies for the eight selected accident scenarios. sequences; and
Figure 3 shows risk model for explosion case. b. -distributed approach - which provides
control of escalation of accidents, together
with the possibility of influencing the later
stages of escalation of other, perhaps
unrelated, accidents. And this followed by
assessment of the control options as a
function of their effectiveness against risk
Loading Condition
Loading Condition
Model
Model
reduction.
Engine
Engine
room
room Fire Protection Model
Fire Protection Model
CONSEQUENCE
STEP 4 : COST BENEFIT ASSESSMENT (CBA)
Cargo leakage Model
Cargo leakage Model
Fire Explosion
Fire Explosion
Model
Model consequence
consequence
Accommodation
Accommodation
Risk -Cost - Benefit analysis to deduce mitigation and
LPG Hazard Model
LPG Hazard Model
options selection Proposed need for new regulations based on
Suvivability Model
Suvivability Model mitigation and options
Compressor
Compressor
room
room
Evacuation model
Evacuation model
i. CBA quantification of cost effectiveness that provide
basis for decision making about RCO identified, this
Fig. 3: Risk model for explosion scenario include the net or gross and discounting values.
ii. Cost of equipment, redesign and construction ,
documentation, training , inspection maintenance and
Identification of accident scenario that is significant to drills, auditing , regulation , reduced commercial used
risk contribution should consider use of: and operational limitation ( speed , loads )
iii. Benefit could include , reduced probability of fatality
,injuries, serenity and negative effects as well as on
health , severity of pollution and economic losses
i. Holistic risk assessment of major treat using RBA and
OBS oodel including application of stochastic.
STEP 5 : DECISION MAKING
ii. Probabilistic and deterministic methods to increase This step involves:
reliability and reduce uncertainties as much as
possible this including using tool comprising i. Discussion of hazard and associated risks
foreseeable scenarios and scenario event, such tolls ii. Review of RCO that keep ALARP
are : iii. Comparison and rank RCO based on associated cost
a. Accident modeling model and benefit
b. Estimation of risk, accident frequency and
consequences Specification of recommendation for decision makers output
could be use for “beyond compliance” preparedness and
rulemaking tools for regulatory bodies towards measures and
STEP 3 - RISK CONTROL contribution for sustainability of the system intactness, our
planet and the right of future generation. In order to select
Risk control measures are used to group risk into a limited between alternative technical or regulatory solutions to
number of well thought out practical regulatory options. specific problems the first three RBA steps (HAZID, risk
Consideration should focus on: assessment, RCOs) can fit into the development of high-level
goals (Level 1) and functional requirements (Level 2) of OBS.
i. Specification of risk control measures for identified Equally, the last three steps (RCOs, CBA, and
scenarios Recommendations) could feed into Level IV and V of OBS
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11. Canadian Journal on Environmental, Construction and Civil Engineering Vol. 2, No. 5, June 2011
XII. UNCERTAINTY risk acceptance criteria for crew and society for LPG tankers
should be established prior to and independent of the actual
Uncertainty will always be part of our activities because of risk analysis. The overall risk associated with LPG carriers
limitation of knowledge of unseen in real world settings, issues should be concentrated in the reduction desired areas ALARP,
associated with uncertainty are normally. where cost effective risk reduction measures should be sought
in all areas. Three areas or generic accident scenarios where
i. Influences on recovery process which together are responsible for about 90% of the total risk
are: Collision, grounding and contact, and they are related in
ii. Test of new advancements
that they describe situation where by the LPG vessel can be
iii. Influence on policy damaged because of an impact from an external source support
inland water like vessel or floating object, the sea floor or
iv. Address system changes over time submerged objects, the quay or shore or bad weather. Figure 4
and 5 show prescription risk acceptability analysis graphs.
v. services & resources
Estimating uncertainty including further validation, policy
issues and rating could be obtained through the relation:
R(P1c) = R(E1) x W(E1,P1) + R(E2) x W(E2,P1) + R(E4) x
W(E4,P1)
Where R= rating, E= environmental factor, P= Policy factor
Uncertainty is necessary because of highly variable nature
of elements and properties involved with the situation require
simulate of extreme condition and model – using combination
mathematical modeling and stochastic techniques while
considering all factors in holistic manner that cover:
i. Risk areas and assessment – taking all practical using
historical data’s and statistics that include all factors -
Public health (people > other species)
Fig. 4: ALARP diagram – Source [IMO]
ii. Mitigation of risk assessment and risk areas - This - 0. 0. 1. - 0. 0. 1. - 0. 0. 1. 1.
1.0 0 5 0 1. 0 0 5 0 1. 0 0 5 0 0
involves making permanent changes to minimize 0.
0
effect of a disaster- Immediacy: (Immediate 1.
A -
1.0
0
threat>delayed threats) 0.
0
-
B
1.0 1.
iii. Panel of expert -Reach out to those who are capable
0
0.
0
to extend hand and do the right thing at the risk area- 1.
C -
1 .0
0
Uncertainty (More certain > less certain) 0.
0
-
D
1.0
1.
iv. Community participation - Educate all concern about 0
0.
0
the going and lastly place firm implementation and 1.
E -
1.0
monitoring procedure. For adaptability (Treatable > 0
0.
0
untreatable) -
1.0
F
1.
0
0.
0
v. Emergency response – provide monitoring and G -
1.0
information facilities and make sure necessary -
1.0
0.
0
0.
5
1.
0
-
1 .0
0.
0
0.
5
1.
0
-
1 .0
0.
0
0.
5
1.
0
-
1.0
0.
0
0.
5
1.
0
information is appropriately transmitted and received
by all
XIII. RISK ACCEPTABILITY CRITERIA
Fig.5 Matrix plot analysis of system ALARP
The diagram below gives overall risk reduction areas By studying the risk models associated with these scenarios,
identification and preliminary recommendation, In order to four sub-models in particular stands out where further risk
assess the risk as estimated by the risk analysis, appropriate
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12. Canadian Journal on Environmental, Construction and Civil Engineering Vol. 2, No. 5, June 2011
reduction could be effective. These are the accident frequency The economic benefit and risk reduction ascribed to each risk
model, the cargo leakage frequency model, the survivability control options should be based on the event trees developed
model and the evacuation model. Particularly, related to during the risk analysis and on considerations on which
collision, grounding and contact, it is recommended that accident scenarios would be affected. Figure 5 shows cost
further efforts in step 3 of this FSA focus on measures relating benefit analysis representative graph. Estimates on expected
to: downtime and repair costs in case of accidents should be based
on statistics from shipyards.
i. Navigational safety. improvements
ii. Maneuverability. Improved maneuverability
Extended use of tugs might reduce the frequency of XIV. BEYOND COMPLIANCE SHIP DESIGN
contact and grounding events near the terminals.
iii. Collision avoidance. i.e. warning boats in busy waters Existing design tools cannot, at least with any degree of
to clear the way for the LPG carrier. reliability, be used to design a vessel to operate will ensure
iv. Cargo protection. Measures to prevent spillage environmental reliability for LPG ships and operation in
through enhancing the cargo containment system’s shallow or restricted waters. This is because of the extreme on-
ability to maintain its integrity linearity of hull and propulsion characteristics under these
v. Damage stability. Reducing the probability of sinking conditions. In general, naval architects and marine engineers
though enhancement of survival capabilities in are educated and equipped with knowledge, skills, design
damaged condition processes that permit continuous checking balancing of
vi. Evacuation arrangements and associated consequence constraints and design tradeoffs of vessel capabilities as the
through improvements relating to evacuation design progresses.
procedures, escape route layout or life saving
appliances. Figure 6 shows the CBA balancing The intended result of the process is the best design given
process curve for sustainable design. the basic requirements of speed, payload, and endurance.
Risk control options step 3 can be identified and prioritized at Focus is not placed on top down model of generic design
technical workshops, such meting could consider identification based on risk where all areas of concerned are assessed at
and selection of risk control options for further evaluation and different stages of design spiral as well as risk of
cost benefit assessment. This part of the FSA also contained a environmental consequence for risk involved in operability in
high-level review of existing measures to prevent accidental restricted water. Operational wise, recent time has seen real
release of gas. attempt to fully integrate human operational practices with
Diferent betw cost of polution
een
vessel design.
costt
control andenvironm dam
etal age
M umsumof cost
inim C of polutioncontrol
ost
H dam cost w
igh age ith
no control
N econom gainfrom
o ic
polusion control
C of dam from
ost age
polution
M umsumof cost
inim
Fig. 6 Cost Benefit Analysis
Figure 7: Ship Design Spiral
Acceptable quotient-= BENEFIT
RISK / COST (1)
Evolving simulation technology, however give hope for
assessment of extreme engineering to mitigate extreme
67