A TRAINING MANUAL
Development of a familiarization training to guarantee
safety on board gas-fuelled tankers
HZ University of Applied Sciences De Ruyter Academy Author: Sander van Dun 1st reader: Mr. De Groot
2nd reader: Mr. Meerburg
A TRAINING MANUAL
Development of a familiarization training to guarantee
safety on board gas-fuelled tankers
HZ University of Applied Sciences De Ruyter Academy Author: Sander van Dun 1st reader: Mr. De Groot
2nd reader: Mr. Meerburg
Abstract
In the ‘Interim Guidelines on safety for natural gas-fuelled engine installations in ships’, it is stated that the whole operational crew of a gas-fuelled cargo ship and passenger ship should have necessary training in gas-related safety, operation and maintenance prior to the
commencement of work on board. Therefore, a ‘category A’ training manual should be developed and a training programme and exercises should be specially designed for each individual vessel and its gas installations. This report is about the development of such a training manual on board the LNG fuelled gas tanker Coral Methane. The purpose of this
research is therefore to develop a training aboard which ensures that Anthony Veder meets the operational requirements in chapter 8 of the interim guidelines on safety for natural gas-fuelled engine installations in ships.
To answer the main research question and more importantly to write a familiarization training three sub questions are formulated. Based on the DNV Standard No. 3.325, several data collection methods are used in this research to answer these questions. During onboard training on the Coral Methane relevant questions were asked, observations were made and existing documents were used. The DNV standard is used as a topic list during observations, during desk research and during informal interviews. Based on this topic list, observations were made and relevant questions were asked to give substance to the familiarization training and to check the results.
Research on board the Coral Methane resulted in a checklist containing the LNG familiarization. The complete training manual with all the required knowledge is added in appendix D.
Important subjects are properties of LNG, boiling point, boil off, hazards, contingencies, cargo containment, safety systems, venting system and the fuel gas system.
Table of Content
1. Introduction ... 5 2. Theoretical framework ... 8 3. Method ... 11 4. Results ... 13 5. Discussion ... 206. Conclusion and recommendation ... 23
Abbreviations ... 25
Figures and tables ... 26
Bibliography ... 27
Appendix A Ship’s particulars ... 30
Appendix B Safety Bulletin ... 31
Appendix C MSDS ... 32
Appendix D Training manual ... 33
Appendix E ESD system ... 76
Appendix F Hazardous areas ... 77
Appendix G Emergency Procedure 6 ... 78
Appendix H Emergency Procedure 9 ... 79
Appendix I Emergency Procedure 5 ... 80
Appendix J Piping diagram Gas fuelled machinery space ... 81
Appendix K Cargo tank #1 ... 82
Appendix L Reliquefaction plant part 1 ... 83
Appendix M Reliquefaction plant part 2 ... 84
1. Introduction
This research is conducted on behalf of the Dutch shipping company Anthony Veder and will be executed on board of the Coral Methane. The Anthony Veder Group was founded in 1937 as a ship owner and port agent. Under the name ‘Oranje Lijn’ the ship-owner maintained a freight scheduled service, a passenger service and some reefer services. In 1958 the ‘Oranje Lijn’ was sold by the Anthony Veder Group and a start was made with fruit transport and port
operations. During these years the shipowner’s vessels sailed under the Netherlands Antilles flag and the company started naming vessels which begin with coral followed by the name of a type of coral. Over the years the shipowner increased the number of refrigerated ships and expanded into gas tankers and container ships. In 1969, they started operating their first gas tankers, in 1991 the decision was made to focus exclusively on the transport of gas. Nowadays, they are involved in all segments of the gas market from CO2 to ethylene and from LPG to LNG. At the end of 2014 the 75-year-old shipowner operates more than thirty ships, of which more than twenty are owned by the company (Anthony Veder, 2015).
In 2009 Anthony Veder launched the “Coral Methane” as world’s first small scale combined LNG/LPG/LEG carrier. The vessels principal particulars are added in appendix A of this report. The development of this unique ship started in 2006 as an innovative study by Anthony Veder for Norwegian client Gasnor. Gasnor produces and distributes natural gas as a clean energy source to various places in Norway. A challenging logistical solution for Gasnor was found in Anthony Veder’s optimal size and flexibility in the conceived vessel. A unique concept was developed for a small scale carrier with diesel-gas-electric propulsion with POD’s for maximum operational flexibility, manoeuvrability and safety in Norwegian’s fjord located small ports and terminals. A major operational challenge was found in transporting LNG from large terminals to various small scale terminals along the Norwegian coast. Therefore the ship is equipped with 2 manifolds (high and low) and flexible hoses in order to succeed in different types of LNG transfers from ship to shore and vice versa. The Coral Methane is suitable for shipping various cargoes which makes the vessel deployable in multiple trades resulting in higher than average utilization rates of the vessel. After several years of service the Coral Methane has proved to be a successful logistical concept and solution for transporting LNG to numerous remote places in an environmentally responsible way. The vessel forms an unique example and benchmark for various small scale LNG opportunities that exist around the globe and are moving towards feasible business cases with our help (Anthony Veder, 2014).
Anthony Veder is a Dutch shipping company that is specialized in shipping liquefied gas products and has developed long-term relationships with clients in the oil & gas industry. The focus is on the segments of petrochemical gases, Liquefied Petroleum Gas, Liquefied Natural
Gas, Ammonia, and Carbon dioxide (Anthony Veder, 2014). Currently Anthony Veder is
expanding its LNG fleet because the company believes that LNG is an alternative cleaner energy source for various industries such as power generation and bunker fuel for other ships
(Anthony Veder, 2014). In 2008 Anthony Veder even won the Innovation Award of the Royal Association of Dutch Shipowners when the Coral Methane was launched as world’s first small scale combined LNG/LPG/LEG carrier. The Coral Methane is equipped with two gas fueled engines which run on LNG cargo boil-off gas (BOG) and two diesel electric engines (Ship-technology.com, 2014). Currently Anthony Veder is sailing with at least four ships which use LNG in the propulsion. In November 2014 Anthony Veder presented two new liquefied natural gas powered sea vessels (Anthony Veder, 2015). With the stricter requirements in MARPOL in emissions of SOx and NOx it is possible that several more ships within Anthony Veder and possibly other companies switch to LNG as a fuel. For example, the shipping company
‘Chemgas’ has taken a new vessel into service equipped with a dual fuel propulsion system and is already building a second gas fuelled vessel (Groen Ervaren, 2015).
The Maritime Safety Committee (MSC) of the IMO noted that the current Safety of Lives at Sea doesn’t have any provisions for use of gas as fuel on ships and recognized the need for the development of a code for gas fuelled ships (Maritime Safety Committee, 2009). As a result the MSC adopted the ‘Interim Guidelines on safety for natural gas-fuelled engine installations in ships’ in resolution MSC.285(86). As the development of LNG fuelled ships is relatively new, there is still no familiarization training on board to become familiar with the matter of LNG in general and to become familiar with the matter of LNG as a fuel. In regards to safety such familiarization can be very important. The developed familiarization can then be used subsequently for the entire fleet. To illustrate the need of a code for gas fuelled ships and to illustrate the need for training of the crew, a copy (Appendix B) is added of an incident on board a Anthony Veder vessel where an AB and a jetty man came in touch with cold propylene vapour and liquid. Although this incident is cargo-related and propylene isn’t used as a fuel in the ships propulsion, it typifies the dangers of cold liquefied gas and the need of basic knowledge for the complete crew.
Therefore the purpose of this research is to develop a basic familiarization trainingaboard which ensures thatAnthony Vedermeets the operationalrequirements in chapter 8ofthe interim guidelines on safety for natural gas-fuelled engine installations in ships. With such a familiarization training seafarers will be familiar with their roles and responsibilities on board whilst at the same time unnecessary bureaucracy and complexity of training and certification is avoided (Hull, 2013). In the end, a training manual can be developed and a training programme and exercises should be designed for each individual vessel and its gas installations. However the framework of such a training manual could be used for the entire fleet of Anthony Veder.
The following research question is formulated: "What knowledge in the familiarization of
Anthony Veder aboard the Coral Methane is required to guarantee the efficient maritime operations and the safety of lives at sea in order to meet the temporary guidelines of the IMO regarding safety for ships using LNG which are adopted on 1 June 2009?". To give a proper
answer to this main question, the following sub questions are formulated that are answered during the study.
1. What basic knowledge is necessary in LNG-related safety?
2. What basic knowledge is necessary in the ship’s specific fuel gas system?
The following chapters of this report are about the theoretical framework, the methods of research, the results, discussion and conclusion. The theoretical framework introduces and describes information and previous research about the subject and explains what the research problem is and more important why it exists. In the chapter ‘Methods’ the type of research and the CARS checklist will be described. In the chapter ‘Results’ the outcome of the research on board the Coral Methane is described.
2. Theoretical framework
MarpolIn 1973 the International Maritime Organization (IMO) adopted The International Convention for the Prevention of Pollution from ships. For several times this convention, known as
MARPOL, has been updated with relevant amendments. Annex VI of this MARPOL convention is about air pollution from ships and limits the main air pollutants contained in ships exhaust gas, including sulphur oxides (SOx) and nitrous oxides (NOx), and prohibits deliberate emissions of ozone depleting substances. The latest changes of this Annex VI are a progressive reduction globally in emissions of SOx, NOx and particulate matter and the introduction of emission control areas (ECAs) to reduce emissions of those air pollutants further in designated sea areas (International Maritime Organization, 2014). It has been found that gas engines achieve a 100% reduction in SOx and particulate emissions and around 92% reduction in NOx emissions in comparison with the engines burning heavy fuel oil. Gas engines also cut down carbon dioxide (CO2) emissions by up to 25% (Ship-technology.com, 2014). Therefore it is stated that vessels which operate on natural gas will contribute to the improvement of air quality (Boon, 2012).
Properties
In appendix C a Material Safety Data Sheet (MSDS) issued by Anthony Veder is added, this MSDS shows the properties and dangers of liquefied natural gas. LNG consists primarily of methane (93,5%) but also contains parts of ethane (5%), propane (1%) and butane (0,5%). LNG is colorless, extremely flammable and extremely cold. It should be kept away from
heat/sparks/open flames and hot surfaces. At high concentrations, the gas can cause some dizziness and seem overpowering. At higher concentrations, impaired consciousness and suffocation may occur because the atmospheric oxygen is displaced. Contact with the product of LNG may cause frostbite in eyes and skin (Anthony Veder, 2009). LNG isn’t dangerous, toxic and corrosive as a liquid. In a storage tank LNG can’t explode or burn because there is no oxygen present. If LNG is released, it will evaporate immediately because it is heated by the ambient temperature. As it evaporates, it will spread quickly because it is lighter than air. The vaporized LNG, or natural gas, can only burn if there is an ignition source and if there is a correct air / gas ratio (Port of Rotterdam, 2014).
Interim Guidelines
In the Netherlands, the latest changes in the Standards of Training, Certification and
Watchkeeping (STCW), the Manilla Amendment, are implemented in de ‘Wet Zeevarenden’ (Inspectie Leefomgeving en Transport, 2014) and they have ensured that necessary global standards will be in place to train and that seafarers will be certified to operate technologically-advanced ships for some time to come (International Maritime Organization, 2015). However in
the field of gas tankers the latest changes are only about gas as a cargo. Before the Manilla Amendments were entered into force an advanced training for liquefied gas tanker cargo operations already existed. The Manilla Amendments added a basic training for liquefied gas tanker cargo operations and made some changes within the advanced training (Inspectie Leefomgeving en Transport, 2014). The Maritime Safety Committee (MSC) of the IMO noted that the current Safety of Lives at Sea doesn’t have any provisions for use of gas as fuel on ships and recognized the need for the development of a code for gas fuelled ships. As a result the MSC adopted the ‘Interim Guidelines on safety for natural gas-fuelled engine installations in ships’ in resolution MSC.285(86). By adopting these interim guidelines the MSC is also inviting governments to apply the guidelines (Maritime Safety Committee, 2009). About the same time with the interim guidelines the IMO developed a new draft international code of safety for ships using gases or other low-flashpoint fuels (IGF code). The IGF code wants to provide mandatory provisions for the arrangement, installation, control and monitoring of machinery, equipment and systems using low flashpoint fuels, such as liquefied natural gas (LNG), to minimize the risk to the ship, its crew and the environment, having regard to the nature of the fuels involved. This IGF code applies to new ships and to existing ships converting from the use of conventional oil fuel to the use of gases or other low-flashpoint fuels, on or after the date of entry into force of the Code (International Maritime Organization, 2015).
Categories
Several operational requirements are already mentioned in the guidelines and in the IGF code. First of all, the whole operational crew of a gas fuelled cargo ship should have necessary
training in gas-related safety, operation, and maintenance prior to the commencement of work on board. Additionally, crew members with a direct responsibility for the operation of gas-related equipment on board should receive special training and this should be documented by the company. Gas-related emergency exercises should be conducted at regular intervals. Last but not least a training manual should be developed and a training programme should be designed for each individual vessel and its gas installations (Maritime Safety Committee, 2009). In its current form the interim guidelines divided the necessary training on gas-fuelled into three categories. These three categories are the basic training for the basic safety crew, supplementary training for deck officers and supplementary training for engineer officers. It is the intention of the Royal Association of Dutch Shipowners that only the first category will be trained on board of the vessel, the other two categories are intended to be trained at a shore based accredited training facility (KVNR, 2013). The basic training for the basic safety crew is called ‘Category A training’ and should provide a basic understanding of LNG, the technical properties of liquid and compressed gas, explosion limits, ignition sources, risk reducing and consequence reducing measures, and the rules and procedures that must be followed during normal operation and in emergency situations. This training is based on the assumption that the crew does not have any prior knowledge of gas, gas engines and gas systems. The training
should consist of both theoretical and practical exercises that involve gas and the relevant systems, as well as personal protection while handling liquid and compressed gas. Category B and C training is the advanced training, a supplementary training for deck and engineer officers. The ship’s maintenance manual, gas supply system manual and manual for electrical equipment in explosion hazardous spaces and zones should be used as a basis for this part of the training (Maritime Safety Committee, 2009). Where Category A is more about gas-related awareness and gas-related safety in general, are category B and C more about the operations and the maintenance of gas equipment.
Standard
DNV is a global provider of knowledge for managing risk. The core competence of DNV is to identify, assess and advice on risk management. They develop and apply standards because of their leading position in certification, classification, verification and training. The purpose of DNV is safeguarding life, property and the environment (Det Norske Veritas, 2013). As a result of the interim guidelines, the IGF Code and more upcoming legislation one of the biggest international classification society Det Norkse Veritas (DNV) developed a table of competences that seafarers should possess when sailing on a LNG fuelled vessel. This table of competences is using the three categories listed above as well (Det Norske Veritas, 2013). Within the
development of this table DNV used IMO resolution MSC.285(86) and the LNG Shipping Suggested Competency Standards (SIGGTO). This concrete implementation of the three mentioned categories has led to a standard, Standard No. 3.325 “Competence Related to the On board Use of LNG as Fuel” (KVNR, 2013). This standard aims to cover important aspects related to the use of LNG as a fuel and aims to provide guidance for establishing a competence foundation, both for vessels with pressure tanks and atmospheric tanks. The standard aims to identify a base set of competencies for the crew and for key personnel involved in LNG related activities on board (Det Norske Veritas, 2013). The purpose of this research is to develop a familiarization training aboardwhich ensures thatAnthony Vedermeets the operational requirements in chapter 8ofthe interim guidelines on safety for natural gas-fuelled engine installations in ships. The Standard No. 3.325, developed by DNV, can be a useful tool to develop this training aboard of the Coral Methane.
3. Method
This chapter is about the method of research and describes the different methods that are used. The main research question is formulated as follows: "What knowledge in the
familiarization of Anthony Veder aboard the Coral Methane is required to guarantee the efficient maritime operations and the safety of lives at sea in order to meet the temporary guidelines of the IMO regarding safety for ships using LNG which are adopted on 1 June 2009?".
The purpose of this research is to develop a familiarization training, a manual, regarding category A of the interim guidelines on safety for natural gas-fuelled engine installations in ships. This basic training in gas-related safety is intended for all seafarers, regardless of role or function, on gas-fuelled cargo and passenger ships. It’s necessary to complete this basic training once in a seafarer’s career, on board or at a shore-based facility. In order to reduce the costs and to avoid unnecessary bureaucracy and complexity of training and certification, Anthony Veder decided to develop this basic training themselves.
It is intended that this developed manual regarding category A will be a reference document to familiarize seafarers in their specific role in relation to LNG. To actually familiarize seafarers on board it is needed to implement the developed familiarization with the already existing
familiarizations on board.
In order to answer the main research question and therefore to develop the familiarization training a qualitative research is executed. This kind of research is executed with relatively little previous knowledge, and as a result the respondent can bring new ideas and insights on the topic of research. To accomplish the purpose of this research several data collections methods will be used. These methods consists of asking relevant questions and observing while
participating in the daily working routine, desk research and informal interviews with junior and senior officers/engineers.
The participation and the observations in the daily working routine aboard the Coral Methane can be used for orientation with the subject of LNG. During this orientation new questions and insights will come up, which can be helpful during the rest of the research. After this orientation it is intended to execute a desk research in order to find answers to the formulated sub
questions. A lot of literature already exists about the subject of liquefied gases, liquefied
natural gas, gas tanker vessels, contingency planning, etcetera. Furthermore, the ship’s manuals on the gas system and all the gas equipment.
The DNV Standard No. 3.325 consists of competence requirements stated in an objective format to define what is expected from a seafarer. This standard can be used as a topic list during participation on board, during observations, during the desk research and during the informal interviews. The DNV Standard determined the necessary competences for category A, B and C. However, this research is only about category A.
The ship’s manuals and the existing literature in the ship’s library can be used to give substance to the familiarization training and to write this training. The table of competences in the DNV Standard is divided into several topics and, therefore, it is intended to write the familiarization topic by topic. First, all information on the topic needs to be gathered and needs to be
processed. Furthermore, it is important to use as many different source materials and perspectives as possible to improve the validity and verifiability of the qualitative research. To prevent wrong interpretations on the subject it is intended to check the results of each topic. Every finished topic will be read by the junior and senior officers/engineers. Comments and remarks will be given by the same junior and senior officers/engineers. Furthermore, it is intended to interview all officers and engineers informally to get new insights on the subject and to check all the data that is gathered from the ship’s manuals and existing literature. It is important to keep up a logbook in which is indicated with whom, where and about what an officer or an engineer was interviewed.
In the end, a complete familiarization training will be the outcome of this research which can be used on board the Coral Methane to familiarize the ship’s crew with the matter of liquefied natural gas.
4. Results
This chapter is about the developed training manual on board the Coral Methane. The actual training manual is added in appendix D of this report. This training manual is a document which contains theoretical and practical knowledge, for example, about liquefied natural gas, its properties, its hazards, contingencies, safety systems and the fuel gas system on board. In chapter 8 of the ‘Interim Guidelines on safety for natural gas-fuelled engine installations in ships’, it is stated that the whole operational crew of a gas-fueled cargo ship and passenger ship should have necessary training in gas-related safety, operation and maintenance prior to the commencement of work on board. A distinction is made in the basic training for all
officers/crew and the advanced training for deck officers and engineers. This research is only about the basic training, the category A training. Therefore, the advanced training concerning gas-related operation and maintenance is not included in this report.
Category A training should provide the basic safety crew with a basic understanding of the gas in question as a fuel, the technical properties of liquid and compressed gas, explosion limits, ignition sources, risk reducing and consequence reducing measures, and the rules and procedures that must be followed during normal operation and in emergency situations. In the theoretical framework of this report, the developed DNV Standard No. 3.325 is already mentioned. In a letter to the Dutch ‘Werkgroep Tankvaart (WTV)’, the Royal Association of Dutch Shipowners stated that the competence table in this standard is a proper tool that can be used in the development of the training manual. Therefore, important general aspects related to the use of LNG as a fuel, coming from the competence table, are present in the training manual. The important general aspects are supplemented by some ship-specific arrangements. In this chapter the complete process of developing the training manual will be described. The purpose of this research is to develop a familiarization training, a manual, regarding category A of the interim guidelines on safety for natural gas-fuelled engine installations in ships. In this chapter an explanation will be given of the way this purpose is accomplished.
First of all, a lot of informal interviews or conversations were conducted in the 5 months on board. Sometime these conversations were used to get new insights on the subject, sometimes they were used to check and verify the results. Names aren’t mentioned, only the rank and the time the officer/engineer was on board. During the complete research, the following officers and engineers were informally interviewed:
Captain 2 (week 13 – 23)
Chief Engineer 2 (week 14 – 26)
3rd Engineer 2 (week 12 – 22)
Chief Officer 1 (week 6 – 13 and 23 – 26)
Chief Officer 2 (week 13 – 23)
2nd Officer 1 (week 6 – 16) 2nd Officer 2 (week 16 – 26) 3rd Officer 1 (week 8 – 18)
During the first 8 weeks of the research, week 6 till 14, the Coral Methane was transporting LEG and, therefore, the diesel engines were still in use. After these 8 weeks, the Coral Methane changed grade to LNG after inerting, gassing up and cooling down of the cargo tanks. From week 14 till 21 the Coral Methane was transporting LNG from Rotterdam to Kristiansund in Norway, where ship-to-ship operations were executed with the Norwegian gas tanker vessel Pioneer Knutsen. During these 7 weeks the gas engines were in use. After departure in Kristiansund, the Coral Methane changed grade again and transported LEG and LPG until the end of the internship.
During the first weeks of the internship it became clear that during a timeframe of only 7 weeks the ship’s engines were running on natural gas. The decision was made to use this timeframe for answering the second sub question about the fuel gas system. The weeks before and the weeks after this timeframe were used to answer the first sub question about the LNG-related safety.
To answer the main research question, two sub questions are formulated. Therefore, the training manual consists of two parts. Part I of the manual is the part with all the basic
knowledge concerning the first sub question, part II of the manual is the part with all the basic knowledge concerning the second sub question.
The competence table in the DNV Standard consists of 12 topics. These topics are general knowledge and understanding, the storage system, the gas supply system, the LNG monitoring system, venting and ventilation, compressors, safety systems and components, auxiliary systems, bunkering, tank conditioning, warm up and heating, contingencies.
In the first topic of the DNV Standard, general knowledge and understanding, there is no distinction made between the basic and the advanced training. This topic is about physics, chemistry, hazards, MSDS, cryogenic, risk awareness, health and safety. Using the company’s safety management system, ‘Liquified Gas Handling Principles On Ships And In Terminals’, the TGE Marine Gas Engineering ship’s manuals and literature published by the ICS, OCIMF & SIGTTO a start was made with answering the first sub question. After completion of this topic,
the draft version was read by 2nd Officer 1. Additionally, Chief Engineer 1, Chief Officer 1 and 2nd
Officer 1 were informally interviewed on the topic to check and improve the results. The second topic of the DNV Standard, the storage system, is about bunker tanks, bunker transfer arrangement, tank connection space, pressure and temperature control. The part about the tank connection space is category A training. The rest of this topic is only category B/C and thus not present in the manual. After completion of this topic, the draft version was discussed during an informal interview with the 3rd Officer.
The third topic of the DNV Standard, the gas supply system, is about repairs and exchanging parts, cryogenic valves and pumps, in-tank pumps and spray pumps. The complete topic is about maintenance of valves and operation of several pumps. This concerns only category B and C and is therefore not present in the manual. This also applies for the fourth topic, the LNG monitoring system.
The fifth topic of the DNV Standard, venting and ventilation, is about vent outlets, air locks, ventilation system, double walled piping and ignited vents. However, double walled piping is not present in this manual. According the IGC Code, gas supply lines passing through enclosed spaces should be completely enclosed by a double walled pipe or a duct. In the case of Coral Methane the gas fuel piping is installed within a ventilated duct. The air space between the gas fuel piping and the wall of the duct is equipped with mechanical pressure control ventilation having a capacity of at least 30 air changes per hour. Therefore, the decision was made not to include more information about double walled piping. After completion of this topic, the draft version was read by the 3rd Engineer. Additionally, Chief Engineer 2 and the 3rd Engineer were
informally interviewed on the topic to check and improve the results.
The sixth topic of the DNV Standard, high duty compressors, is only category B and C training and isn’t considered basic knowledge. However, the compressors are an important part of the fuel gas system and therefore some information about the compressors are present in part II of the manual.
The seventh topic of the DNV Standard, safety systems and components, is about the gas detection system, emergency shutdown system, safety relief valves, fire detection system and EX-certified equipment. Every item consists of category A, B and C training. Concerning the gas detection system, it’s important that every seafarers is capable of describing and locating the gas detection system and the alarm panel. Performing maintenance, change over the sampling points and calibrating the gas detection is typically category B/C training and therefore not in the manual. This also applies for the other items within this topic. Only, a brief description on locations and components of the emergency shutdown system, safety relief valves and the EX-proof equipment is required. Explaining the emergency shutdown sequence, performing tests,
performing emergency closing of safety relief valves and repair EX-certified equipment is all category B and C training and not present in the manual. After completion of this topic, the draft version was read by the 2nd Officer 1 and 2. Additionally, Chief Officer 2 and 2nd Officer 2
were informally interviewed on the topic to check and improve the results.
The eight topic of the DNV Standard, auxiliary systems, is about the inert gas generator, air and inert gas dryers, gas heaters, cargo vaporizers and water curtain. According the DNV Standard none of the items are category A training. However, information about the inert generator and the water curtain is present in this manual. The inert gas generator is called the PSA-skid and is located in the PSA room. This room is equipped with a fixed oxygen measurement system due to the risk of asphyxiation. The same room has to be entered frequently by the deck crew to start the winches for mooring and anchor operations. Risks exist when entering a space containing nitrogen systems. Therefore, some basic knowledge on nitrogen and the nitrogen generator can be of added value. For the same reason, basic knowledge on the water curtain near the lower and upper manifolds is presented in the manual. The OS and one of the AB’s never participated in LNG operations, only in LEG and LPG operations where the water curtain isn’t used. Explanations on the purpose of this curtain had to be given several times. After completion of this topic, the draft version was read by 2nd Officer 2. Additionally, 2nd Officer 2
was informally interviewed on the topic to check and improve the results.
The ninth, tenth and eleventh topics of the DNV Standard are respectively about bunkering, tank conditioning and warm/heating. These topics are only category B/C training and it isn’t necessary to present this in the manual. The topic bunkering isn’t really applicable because the Coral Methane is using the boil-off gas from the cargo tanks and isn’t depending on a bunker barge to be operational. Tank conditioning is about warming up, gas freeing, inerting and purging of the cargo tanks. Inerting is already mentioned and the other procedures are operational tasks for the officers and not for the entire crew.
The twelfth topic of the DNV Standard, contingencies, is about general aspects of
contingencies, spills, leaks, fire, emergency shutdown, emergency unloading and emergency release. Drills are performed on a regularly basis to train emergencies in case of a spill, leakage or fire. It’s of upmost importance for your own safety and for the safety of others to know what happens if there is a spill or a leakage. Determining a safe position and taking appropriate action in case of an emergency is considered basic knowledge for the entire crew. After completion of this topic, the draft version was read by 2nd Officer 2. Additionally, Captain 2,
Chief Officer 2 and 2nd Officer 2 were informally interviewed on this topic to check and improve
On the basis of the 12 topics in the DNV Standard, Part I of the training manual is developed. Part II of the training manual is about the fuel gas system. Part II is developed during the 7 weeks the Coral Methane was performing ship-to-ship operations.
When the Coral Methane is transporting LNG, the boil off gas in the cargo tank is used for the propulsion of the ship. Especially during manoeuvring, it can be a very complex process to keep the gas engines running. A lot of knowledge and skills are expected from the officer of the watch. In appendix D, more detailed information is given about the complete boil off process. During manoeuvring, the ship’s speed will be decreased and increased, as a result less or more fuel gas is needed. If the compressors are still on 100% production rate when the ship’s speed is decreasing, the pressure in the fuel gas buffer vessel keeps rising because the production rate is higher than the consumption rate in the gas engine. If the pressure in the buffer vessel is too high, hot boil off gas will be blown into the cargo tank. An unwanted situation. The compressors are equipped with a manual switch to change over to 50% production rate. However, if the compressors are running on 50% and the consumption rate of the engines is higher, the
pressure in the buffer vessel will decrease. At a certain point, the low alarm, the pressure is too low and the diesel engines are started automatically. An unwanted situation as well, especially when manoeuvring. A complex process, which needs to be monitored constantly by the officer of the watch. Officially, if necessary, the officer of the watch needs to leave the bridge and thus the bridge team to manually switch over the compressors. Due to lack of experience and lack of knowledge by the third mate, it happened several times that the second mate or chief mate had to interfere. It can be concluded that a familiarization on the subject of the fuel gas system is an addition to junior officers.
A lot of basic knowledge about the fuel gas system on board is added in part II of the manual. It’s important to know what is happening, why it is happening and what the possible dangers are. Basic knowledge is presented on applicable IGC-Code legislation, the gas fuelled machinery space and the principle of operation of the gas engine. For instance, the new Indonesian 3rd
Officer didn’t have any experience with LNG propulsion. One week after his on-signing, a change of grade took place and the engines were running on diesel again. Six or seven weeks later he noticed the mechanical ventilation for the gas fuelled machinery space (figure 8). The importance of this ventilation system wasn’t clear to the junior officer due to lack of
knowledge. A small introduction on this matter can be an addition.
After orientation and observation of the complete fuel gas system, from boil-off gas leaving the cargo tank to entering the gas engine, Part II is developed on the basis of the IGC Code, TGE Marine Gas Engineering ship’s manuals, Rolls Royce service manual and the company’s SMS. Part II was read by the 3rd Engineer. Additionally, the 3rd Engineer, Chief Engineer 2 and 2nd
According to IMO regulations, all newly joined crewmembers are to receive an on board familiarization training and are to complete the familiarization checklist for newly joined
crewmembers before being assigned to shipboard duties. Standard familiarization forms are on board every Anthony Veder vessel and have to be filled in for each crewmember. In order to completely familiarize the ship’s crew with the use of LNG, the developed training manual has to be implemented on board. A simple way to implement the manual is to make a LNG checklist which can be added to the ship’s general familiarization checklist. The newly joined
crewmember can then be guided around the vessel and can receive instructions on the following:
Part I LNG
LNG and other marine fuels Density
Boiling point and boil off Cargo containment Inerting Dew point Hazards Flammability Asphyxia Low temperature MSDS BLEVE Contingencies
Spills and leaks Fire
Safety systems
Gas detection systems
Emergency Shutdown Devices Safety relief valves
Fire detection systems Hazardous areas Venting system
Part II
Fuel gas system
Gas engine room Principle of operation
This checklist makes sure that the crew on board is more aware of specific points of attention related to LNG and that there is a constant safety awareness to work with or in the vicinity of LNG.
5. Discussion
This research is conducted on behalf of the Dutch shipping company Anthony Veder and is executed on board of the Coral Methane. In the current Safety of Lives at Sea there aren’t any provisions for use of gas as fuel on ships and therefore there is a need for the development of a code for gas fuelled ships. As a result the ‘Interim Guidelines on safety for natural gas-fuelled engine installations in ships’ are adopted. Furthermore, there is no familiarization training on board to become familiar with the matter of LNG in general and to become familiar with the matter of LNG as a fuel. In regards to safety such familiarization can be very important, therefore a training aboard is developed which ensures that Anthony Veder meets the
operational requirements in chapter 8 of the interim guidelines on safety for natural gas-fuelled engine installations in ships.
In chapter 8 of the ‘Interim Guidelines on safety for natural gas-fuelled engine installations in ships’, it is stated that the whole operational crew of a gas-fueled cargo ship and passenger ship should have necessary training in gas-related safety, operation and maintenance prior to the commencement of work on board. A distinction is made in the basic training for all
officers/crew and the advanced training for deck officers and engineers. This research is only about the basic training, the category A training. Therefore, the advanced training concerning gas-related operation and maintenance is not included in this report.
The purpose of this research is to develop a familiarization training, a manual, regarding category A of the interim guidelines on safety for natural gas-fuelled engine installations in ships. To accomplish this purpose, a qualitative research is executed. Important is to minimize subjectivity and interpretations within the research and to improve the validity and verifiability of the research.
In order to validate the collected information, as many different source materials as possible were used. The on board research started with the participation and the observations in the daily working routine. While participating in the engine room and on deck observations were made and questions on the subject were asked. After the orientation a start was made with part I and II of the training manual. A lot of existing material was studied in order to find an answer to the sub questions. In all probability, the theory about gas and its properties and dangers will not change when researched by another researcher at a different time and a different location. A lot of information retrieved from the used literature can be considered trustworthy, accurate and credible. Information on technical properties of liquid and
compressed gas, explosion limits, ignition sources and risk reducing can be found in multiple sources and thus be checked. For instance, the information on explosion limits is retrieved from a ‘De Ruyter Training & Consultancy’ reader. However, ditto information can be found in
‘Liquefied Gas Handling Principles On Ships And In Terminals’ and in the ‘International Safety Guide for Oil Tankers and Terminals’. This is the case for a lot of existing literature that is used for writing the manual. Overlay exists between the different sources and the information within.
To check all the information retrieved from the existing literature and manuals, a member check was performed. Those involved in the study read the results and made their remarks. 2nd
Officer 1 & 2 made the remarks on part I of the manual, the 3rd Engineer made the remarks on
the part II of the manual. In principle, member checking is a proper tool to improve the validity and the verifiability of the research. On the downside, the remarks aren’t documented. It’s a possibility that certain information is lost due to the lack of this documentation. Furthermore, maybe more remarks could have been made when more officers/engineers and higher ranked officers/engineers had read the complete manual. Due to lack of time and the daily work of these officers this wasn’t possible.
During the whole research, a lot of questions were asked during informal open interviews with the officers and the engineers. Informal open interviews were also used to check and improve the results. These informal open interviews about the ship’s fuel gas system and gas in general took place on the bridge, in the cargo control room, in the engine control room and on deck. While interviewing notes were taken, these notes were processed into the improvement of the training manual. Interviews are a proper tool to verify the founded results and to create the opportunity to give feedback on the subject. On the downside, a proper logbook isn’t kept to indicate with whom, where and what about the interview took place. Only a list with the ranks of the officers/engineers and the time on board is added in the ‘Results’. Notes from the interviews weren’t documented and it wasn’t possible to record the numerous interviews and to make transcripts of all these interviews. It’s a possibility that certain information is lost due to the lack of documentation. Furthermore, the knowledge on the subject is depending on the person who is interviewed. There’s a possibility that other answers are given and other
knowledge can be obtained during further research and new interviews.
As mentioned before, the gas-related training in the ‘Interim Guidelines’ is divided into three categories. The developed training manual is only about category A and comprises basic
competences for all officers and crew, regardless of role or function. The Interim Guidelines are not about cargo-related gas training, they are about fuel-related gas training. However, it’s a possibility that an overlay between the two separate trainings will exist on various subjects. When it comes to cargo-related gas training, the IMO has made some changes in the STCW. In the Manilla Amendments, a basic training for liquefied gas tanker cargo operations is added and some changes are made within the advanced training. Seafarers with a direct responsibility are expected to have an advanced training certificate, seafarers without a direct responsibility
are expected to have an basic training certificate. A few subjects within this basic cargo related training are inert gas, low temperatures, pressure and brittle fracture. Seafarers with an advanced training certificate, are expected to have the basic training certificate as well. These cargo related gas trainings are mandatory for every seafarer on a gas tanker vessel. It’s
inescapable that a lot of subjects in the cargo related training are discussed in the developed LNG training manual as well. The added value of this report is therefore bigger on passenger ships and cargo ships which use LNG as fuel, than on gas tanker vessels which use LNG as a fuel. In the case of passenger ships and cargo ships, there isn’t any basic or advanced gas training mandatory and therefore there isn’t a lot of knowledge present about gas and its properties and its dangers. A training manual, describing basic knowledge and basic competences, is then extremely useful. The training manual can be used as a guide to familiarize and to train the crew on board. The training manual itself can serve as a reference document for the crew. The developed training manual is divided into two parts, I and II. Part I contains important general aspects of LNG. Therefore, part I can easily be used on other Anthony Veder vessels and on other vessels of other shipping companies. However, part II is very ship’s specific and can’t be used for other vessels than the Coral Methane. For example, the Coral Energy is equipped with a dual fuel engine. Therefore the ship’s specific fuel gas system is different and a different familiarization should be made.
6. Conclusion and recommendation
With this research an effort is made in determining what basic knowledge is required in the familiarization aboard the Coral Methane to guarantee the efficient maritime operations and the safety of lives at sea. A training manual is developed in order to meet the temporary guidelines of the IMO regarding safety for ships using LNG.
In chapter 8 of the ‘Interim Guidelines on safety for natural gas-fuelled engine installations in ships’, it is stated that the whole operational crew of a gas-fueled cargo ship and passenger ship should have necessary training in gas-related safety, operation and maintenance prior to the commencement of work on board. This necessary training comprises of a basic training and an advanced training. The basic training is for the entire crew on board and the advanced training is for deck officers and engineers. This research is only about the basic training, the category A training.
The developed manual contains a general part on LNG operations, part I, and a ship specific part about the fuel gas system, part II. The manual has been divided into two parts because the fuel gas system contains more detailed and complex information. Perhaps this part is too complicated for some seafarers in their role or function. It’s a possibility to familiarize only new officers/engineers with this part of the manual.
Regarding Part I, every seafarer is expected to know what LNG is, to understand the
relationship between pressure and temperature, to state the storage temperature of LNG, to understand the LEL/UEL, to explain rapid phase transition, to give a description of boil off gas, to interpret the MSDS, to describe the hazards associated with LNG, to explain a BLEVE, to describe the hazardous areas, understand the term cryogenic, to understand the risks of entering spaces containing nitrogen systems, to understand the function of the hold space and the safe working procedure, to explain the importance and the function of air locks, to explain the critical importance of a functioning ventilation system to ensure provision of LNG to the engine, to describe the gas detection on board, to describe the fire detection on board, to describe the consequences of activating an ESD, to explain the working principle of safety relief valves, to describe locations where EX-proof equipment is required, to act in accordance with applicable contingency plan in case of an emergency and to determine a safe position. This is all considered basic knowledge for the basic safety crew, regardless of their role or function. The question is if it’s realistic and achievable to expect this from an Indonesian Cook, Messman, OS, AB or a Bosun. Already, a lack of English language skills exists among these seafarers.
This research utilized the DNV Standard in the development of the training manual. The DNV Standard utilized the LNG Shipping Suggested Competency Standards from SIGGTO. In the end, all applicable topics and items are included in the developed manual and the manual can be considered a good reflection of the basic knowledge that is expected and is required to guarantee the efficient maritime operations and the safety of lives at sea. However, it’s inevitable that the added value of this manual is much bigger on gas fuelled passenger ships and other cargo ships.
The training manual is a document of 41 pages. In the current form it’s not very user friendly and therefore not a solution for daily use. The training manual should be added in the ship’s Safety Management System. Then, the document can be used perfectly as a reference when seafarers are getting familiarized. On the basis of the developed checklist, the on-signing seafarers can be guided around the ship.
When it comes to follow-up study, it might be an idea to hand over this training manual to new Anthony Veder apprentices. Perhaps the new apprentice can evaluate the training manual and can add important knowledge that is still missing. Furthermore, on the ship’s computer in the cargo control room a lot of CBT’s are present already. CBT’s about numerous subjects;
navigation, English language, GMDSS, Search and Rescue, personal safety etcetera. A CBT about LNG as a fuel is still missing and this can be a useful tool to educate the ship’s crew. Besides the familiarization, a second option would be available then to train the crew and to realize a basic understanding of LNG. This CBT can be developed in the near future, maybe partially by the new apprentice.
Abbreviations
BOG Boil Off Gas
CARS Credibility, Accuracy, Reasonableness and Support CBT Computer Based Training
CO2 Carbon dioxide
DNV Det Norske Veritas ECA Emission Control Area
IGF International code of safety for ships using Gases or other low-flashpoint Fuels IMO International Maritime Organization
LEG Liquefied Ethylene Gas LNG Liquefied Natural Gas LPG Liquefied Petroleum Gas MARPOL Marine Pollution
MSC Maritime Safety Committee MSDS Material Safety Data Sheet NOx Nitrous Oxides
PSA Pressure Swing Adsorption
SIGTTO Society of International Gas Tanker and Terminal Operators SOx Sulphur Oxides
Figures and tables
Figure 1: Constituents of natural gas ... 34 Figure 2: Characteristics of Methane ... 36 Figure 3: Pressure/temperature relationship for hydrocarbon gases ... 37 Figure 4: Cross section Coral Methane ... 40 Figure 6: Pilot operated relief valve (1) ... 52 Figure 7: Pilot operated relief valve (2) ... 52 Figure 5: Flammable vapour zones ... 58 Figure 8: Mechanical ventilation gas fueled machinery space ... 67 Figure 9: Fuel gas buffer vessel ... 69
Table 1: Tank information ... 39 Table 2: Hazards ... 44
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Appendix D
Training manual
1. Training manualThis appendix D is the result of a 5 months research on board the Coral Methane. With the help of manuals, professional literature and the knowledge of several officers and engineers on board, a research is executed in order to develop a familiarization for gas fuelled tankers.
Part I
1.1 LNG
1.2 LNG and other marine fuels 1.3 Density
1.4 Boiling point and boil off 1.5 Cargo containment 1.6 Inerting 1.7 Dew point 1.8 Hazards 1.8.1 Flammability 1.8.2 Asphyxia 1.8.3 Low temperature 1.9 MSDS 1.9.1 IGC code 1.9.2 IMDG code 1.10 BLEVE 1.11 Safety systems 1.11.1 Gas detection system
1.11.2 Emergency Shutdown Device 1.11.3 Safety relief valves
1.11.4 Fire detection system 1.11.5 Hazardous areas 1.12 Contingencies 1.12.1 Spills and leaks 1.12.2 Fire 1.12.2.1 Water 1.12.2.2 Dry powder 1.12.2.3 Carbon dioxide 1.13 Venting system Part II
1.14 Fuel gas system 1.14.1 Gas engine room 1.14.2 Principle of operation
1.1. LNG
LNG is an abbreviation for liquefied natural gas. Figure 1 shows that it is a hydrocarbon mixture, mainly consisting of methane with small quantities of ethane, propane, butane, water, carbon dioxide and nitrogen (Anthony Veder Rederijzaken B.V., 2014). Liquefied natural gas is the liquid form of natural gas, the substance would be a gas at ambient temperature and at atmospheric pressure. The IMO has adopted the following definition for the liquefied gases: Liquids with a vapour pressure exceeding 2.8 bar absolute at a temperature of 37,8 °C. When natural gas is cooled into liquid form, its volume is reduced by a factor of 600, which means LNG uses 1/600 of the space required for the same mass of gas (Freeport LNG Development, 2014).
Figure 1: Constituents of natural gas
Natural gas can be found in underground gas wells, condensate reservoirs and large oil fields. Its composition varies according to where it is found but methane is by far the predominant constituent, ranging from 82 % to 100 %. In addition to the varying amounts of water, carbon dioxide and nitrogen, natural gas contains small quantities of heavier hydrocarbons. These heavier hydrocarbons are known as NGL’s, natural gas liquids, and are made up of ethane, propane and butane. The concentration NGL in raw natural gas varies from one location to another. In general is the concentration of NGL smaller in gas wells compared to large oil fields. Regardless of varying composition, natural gas requires treatment to remove these heavier hydrocarbons and other constituents. This ensures that the product is in acceptable condition for liquefaction or for use a fuel. To produce LNG the raw natural gas is first stripped of condensates, is removed of carbon dioxide and hydrogen sulphide and water vapour. Carbon dioxide must be removed as it freezes at a temperature above the atmospheric boiling point of LNG.
The toxic compound hydrogen sulphide is removed as it causes pollution when being burnt in fuel. More about sulphide in paragraph 1.2. The next step in the liquefaction of LNG is the fractioning unit where all the heavier hydrocarbons (NGL’s) are removed. The NGL’s are split up into propane and butane and are used in the production of chemical gases. However, in this case only the LNG is of importance. After the removal of the heavier fractions the main gas flow now exists mostly of methane. This product is then liquefied into the end product, the liquefied natural gas (White, 2000).
1.2. LNG and other marine fuels
In 1973, the International Maritime Organization (IMO) adopted The International Convention for the Prevention of Pollution from ships. For several times this convention, known as
MARPOL, has been updated with relevant amendments. Annex VI of this MARPOL convention is about air pollution from ships and limits the main air pollutants contained in ships exhaust gas, including sulphur oxides (SOx) and nitrous oxides (NOx), and prohibits deliberate emissions of ozone depleting substances. The latest changes of this Annex VI are a progressive reduction globally in emissions of SOx, NOx and particulate matter and the introduction of emission control areas (ECAs) to reduce emissions of those air pollutants further in designated sea areas (International Maritime Organization, 2014).
NOx forms through a reaction under high temperatures in the main engine. It causes pollution and acidification of air and water. SOx forms through a reaction between oxygen and sulphur in the engine. It causes pollution and acidification of air and water. Particulate matter emissions are caused by burning of fossil fuels and has negative effects on human health and health of vegetation. Particulate matter mostly consists of black carbon (soot) and contributes to global warming and accelerates melting of ice. 1-3% of total SOx emissions are emitted as particulate matter. Therefore, a higher quality of fuel or a different type of fuel don’t only decrease emission of particulate matter, but also the emissions of black carbon and SOx. CO2, carbon dioxide, is the most commonly known and important Greenhouse Gas. Greenhouse Gas exists mostly of CO2. The emission of CO2, and therefore Greenhouse Gases, are caused by burning of fossil fuels. Greenhouse gases and specifically CO2 emissions accelerate global warming
There are different ways to cut these NOx, SOx, particulate matters and CO2 emissions, but only one solution provides “all in one” reduction of all mentioned emissions: LNG as a ship’s fuel will reduce NOx to clearly below Tier III level (for four stroke engines), SOx to zero, particulate matters to about zero and CO2 by about 20 % without any after treatment of combustion gases or exhaust gas recirculation (Harperscheidt, 2011). In this way LNG differs from other marine fuels.
1.3. Density
LNG is transported in a way where the liquid is in contact with its vapour. The density of a liquid is defined as its mass per unit volume. LNG has a liquid density lower than one. Therefore, in the event of a spillage onto water, the liquid will float prior to evaporation. Figure 2 shows that the liquid density of LNG decreases with increasing temperature. It also shows that the vapour density increases with increasing temperature. This is because the vapour is in contact with its
liquid and, as the temperature rises, more liquid transfers into the vapour-phase in order to achieve a higher vapour pressure.
1.4. Boiling point and boil off
Every substance exists in either the solid, liquid or vapour state. For liquefied gases, as LNG, the solid state is not of concern. Temperatures, pressures and latent heats of vaporization and condensation are of fundamental importance. In changing from liquid to vapour (vaporization) heat must be given to the substance, in changing from vapour to liquid (condensation) heat must be given up by the substance. The heat given or given up by the substance is called latent heat.
The boiling point is the temperature at which the vapour pressure of a liquid is equal to the pressure on its surface. The boiling point gives the temperature at which the pure substance evaporates at a pressure of 1,01325 bar. The boiling point of LNG is -162 °C (Anthony Veder Rederijzaken B.V., 2014). An alternative way of describing a liquefied gas is to give the
temperature at which the saturated vapour pressure is equal to the atmospheric pressure, the liquids atmospheric boiling point. In figure 3, it is shown that around -162 °C the saturated vapour pressure is equal to the atmospheric pressure of 1 bar. At this point the substance will change between liquid and vapour.
In situations where pure gases are isolated from their liquids, the ideal gas laws can be applied. In the case of a cargo tank filled with liquid and vapour above this liquid the concept of
saturated vapour pressure becomes important. Vapour in the space above a liquid is in
constant motion. Molecules near the liquid surface are constantly leaving to enter the vapour-phase and molecules in the vapour are returning to the liquid vapour-phase. A saturated vapour is a
vapour in equilibrium with its liquid at that temperature. In this condition, the vapour space can’t accept any further ingress from the liquid without a continuous exchange of molecules taking place between vapour and liquid. In this condition, the substance will change between liquid and vapour. Evaporation, the boiling of the liquid, is a phenomenon where the faster-moving molecules escape from the surface of a liquid. The boiling happens when the vapour pressure is equal to the pressure of the liquid. By varying the pressure above the liquid, the liquid boils at a
different temperature. In figure 3, the relationship between temperature and saturated vapour pressure is presented. If the pressure above the liquid, the tank pressure, has increased the vapour can accept more ingress from the liquid as well to reach the equilibrium state. As a result the boiling point changes and will be higher, and vice versa (White, 2000).
While sailing the cargo in the cargo tank will be constantly boiling, creating a boiling-off gas. The boiling-off gas is the vapour produced above a cargo liquid surface due to evaporation (International Chamber of Shipping, 1995). In the case of the Coral Methane the liquefied gas is carried as a boiling liquid at atmospheric pressure, making it a fully refrigerated vessel. During carriage, the cargo will boil off because of heat ingress through the insulation. Because of this boil off the tank pressure and the temperature of the liquid will rise. Because of the rising pressure, the boiling point automatically changes and rises too and the liquid will evaporate sooner at a higher temperature. The cargo tank pressure shall normally be maintained above atmospheric pressure to prevent the ingress of air and the possible formation of flammable mixtures. In order to control the tank pressure and the cargo temperature on the Coral Methane the boil-off gas is burnt in two gas engines. In emergency cases the boil-off gas can also be vented into the atmosphere (Anthony Veder Rederijzaken B.V., 2014). The boil-off gas is drawn into the cargo compressors in the compressor room, after compression the gas will go to the fuel gas buffer vessel via the LPG condenser. More about the complete fuel gas system in the end of this chapter.
1.5. Cargo containment
The Coral Methane is equipped with 2 cargo tanks, a deck tank and a fuel gas buffer vessel. The fuel gas buffer vessel will be mentioned in paragraph 1.13.
Tank No. Shape Volume MARVS USCG MARVS IMO
Cargo tank 1 Cylindrical 3750 m3 2,98 bar g 3,2 bar g Cargo tank 2 Cylindrical 3750 m3 2,98 bar g 3,2 bar g Deck tank Cylindrical 80 m3 18 bar g 18 bar g
Table 1: Tank information
Each cargo tank is equipped with:
One manhole
Deep well pump
Submerged fuel gas pump
One pump sump
Bottom purge / loading line
Top purge line
Stripping line
Floating level gauge
Visual and audible level alarm system
Overflow control system
Fixed closed temperature gauge with remote indication and audible and visual alarm system
Two individual pilot operated safety relief valves
One connection point for pressure gauge
Five sample lines (top, 50% fore, 50% aft, bottom aft, sump) The deck tank is equipped with:
One manhole
One loading line to the bottom, suitable for tank purging
One vapour connection
One spray line
One stripping line
One level gauge with stilling pipe
One floating level gauge
Visual and audible level alarm system
