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Thursday, November 20, 2014

SOLAS

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 The International Convention for the Safety of Life at Sea (SOLAS) is an international maritime safety treaty. It ensures that ships flagged by signatory States comply with minimum safety standards in construction, equipment and operation. The SOLAS Convention in its successive forms is generally regarded as the most important of all international treaties concerning the safety of merchant ships.





History

Origin and early versions

The first version of the treaty was passed in 1914 in response to the sinking of the RMS Titanic. It prescribed numbers of lifeboats and other emergency equipment along with safety procedures, including continuous radio watches. The 1914 treaty never entered into force due to the outbreak of the First World War.
Newer versions were adopted in 1929 and 1948.

1960 version

The 1960 Convention – which entered into force on 27 May 1965 – was the first major achievement for International Maritime Organization (IMO) after its creation. The 1960 version represented a major advance in updating commercial shipping regulations and in staying up-to-date with new technology and procedures in the industry.

1974 version

The intention had been to keep the Convention up to date by periodic amendments, but the procedure to incorporate the amendments proved to be very slow: it could take several years for the amendments to be put into action since countries had to give notice of acceptance to IMO and there was a minimum threshold of countries and tonnage.
As a result, a complete new convention was adopted in 1974 which includes all the agreements and acceptable procedures. Even though the Convention was updated and amended numerous times, the Convention in force today is sometimes referred to as SOLAS, 1974.
The 1974 version simplified the process for amending the treaty. A number of amendments have been adopted since. The latest Convention in 1974 included the "tacit acceptance" procedure whereby amendments enter into force by default unless nations file objections that meet a certain number or tonnage.
In 1975 the assembly of the IMO decided that the 1974 convention should in future use SI units only.

1988 version

In particular, amendments in 1988 based on amendments of International Radio Regulations in 1987 replaced Morse code with the Global Maritime Distress Safety System (GMDSS) and came into force beginning 1 February 1992. An idea of the range of issues covered by the treaty can be gained from the list of sections (below).

Later amendments

The up-to-date list of amendments to SOLAS is maintained by the IMO. As of April 2013, the most recent amendment dates from May 2011.

 

International Convention for the Safety of Life at Sea (SOLAS), 1974

Adoption: 1 November 1974; Entry into force: 25 May 1980


The SOLAS Convention in its successive forms is generally regarded as the most important of all international treaties concerning the safety of merchant ships. The first version was adopted in 1914, in response to the Titanic disaster, the second in 1929, the third in 1948, and the fourth in 1960. The 1974 version includes the tacit acceptance procedure - which provides that an amendment shall enter into force on a specified date unless, before that date, objections to the amendment are received from an agreed number of Parties.
As a result the 1974 Convention has been updated and amended on numerous occasions. The Convention in force today is sometimes referred to as SOLAS, 1974, as amended.

Technical provisions
The main objective of the SOLAS Convention is to specify minimum standards for the construction, equipment and operation of ships, compatible with their safety. Flag States are responsible for ensuring that ships under their flag comply with its requirements, and a number of certificates are prescribed in the Convention as proof that this has been done. Control provisions also allow Contracting Governments to inspect ships of other Contracting States if there are clear grounds for believing that the ship and its equipment do not substantially comply with the requirements of the Convention - this procedure is known as port State control.The current SOLAS Convention includes Articles setting out general obligations, amendment procedure and so on, followed by an Annex divided into 12 Chapters.
 
Chapter I - General Provisions
Includes regulations concerning the survey of the various types of ships and the issuing of documents signifying that the ship meets the requirements of the Convention. The Chapter also includes provisions for the control of ships in ports of other Contracting Governments.

Chapter II-1 - Construction - Subdivision and stability, machinery and electrical installations
The subdivision of passenger ships into watertight compartments must be such that after assumed damage to the ship's hull the vessel will remain afloat and stable. Requirements for watertight integrity and bilge pumping arrangements for passenger ships are also laid down as well as stability requirements for both passenger and cargo ships.
 
The degree of subdivision - measured by the maximum permissible distance between two adjacent bulkheads - varies with ship's length and the service in which it is engaged. The highest degree of subdivision applies to passenger ships.
 
Requirements covering machinery and electrical installations are designed to ensure that services which are essential for the safety of the ship, passengers and crew are maintained under various emergency conditions.
 
"Goal-based standards" for oil tankers and bulk carriers were adopted in 2010,  requiring new ships to be designed and constructed for a specified design life and to be safe and environmentally friendly, in intact and specified damage conditions, throughout their life. Under the regulation, ships should have adequate strength, integrity and stability to minimize the risk of loss of the ship or pollution to the marine environment due to structural failure, including collapse, resulting in flooding or loss of watertight integrity.

Chapter II-2 - Fire protection, fire detection and fire extinction
Includes detailed fire safety provisions for all ships and specific measures for passenger ships, cargo ships and tankers.
 
They include the following principles: division of the ship into main and vertical zones by thermal and structural boundaries; separation of accommodation spaces from the remainder of the ship by thermal and structural boundaries; restricted use of combustible materials; detection of any fire in the zone of origin; containment and extinction of any fire in the space of origin; protection of the means of escape or of access for fire-fighting purposes; ready availability of fire-extinguishing appliances; minimization of the possibility of ignition of flammable cargo vapour.

Chapter III - Life-saving appliances and arrangements
The Chapter includes requirements for life-saving appliances and arrangements, including requirements for life boats, rescue boats and life jackets according to type of ship. The International Life-Saving Appliance (LSA) Code gives specific technical requirements for LSAs and is mandatory under Regulation 34, which states that all life-saving appliances and arrangements shall comply with the applicable requirements of the LSA Code.

Chapter IV - Radiocommunications
The Chapter incorporates the Global Maritime Distress and Safety System (GMDSS). All passenger ships and all cargo ships of 300 gross tonnage and upwards on international voyages are required to carry equipment designed to improve the chances of rescue following an accident, including satellite emergency position indicating radio beacons (EPIRBs) and search and rescue transponders (SARTs) for the location of the ship or survival craft.
Regulations in Chapter IV cover undertakings by contracting governments to provide radiocommunication services as well as ship requirements for carriage of radiocommunications equipment. The Chapter is closely linked to the Radio Regulations of the International Telecommunication Union.

Chapter V - Safety of navigation
Chapter V identifies certain navigation safety services which should be provided by Contracting Governments and sets forth provisions of an operational nature applicable in general to all ships on all voyages. This is in contrast to the Convention as a whole, which only applies to certain classes of ship engaged on international voyages.
 
The subjects covered include the maintenance of meteorological services for ships; the ice patrol service; routeing of ships; and the maintenance of search and rescue services.
 
This Chapter also includes a general obligation for masters to proceed to the assistance of those in distress and for Contracting Governments to ensure that all ships shall be sufficiently and efficiently manned from a safety point of view.
 
The chapter makes mandatory the carriage of voyage data recorders (VDRs) and automatic ship identification systems (AIS).

Chapter VI - Carriage of Cargoes
The Chapter covers all types of cargo (except liquids and gases in bulk) "which, owing to their particular hazards to ships or persons on board, may require special precautions". The regulations include requirements for stowage and securing of cargo or cargo units (such as containers). The Chapter requires cargo ships carrying grain to comply with the International Grain Code.
 
Chapter VII - Carriage of dangerous goods
The regulations are contained in three parts:
Part A - Carriage of dangerous goods in packaged form - includes provisions for the classification, packing, marking, labelling and placarding, documentation and stowage of dangerous goods. Contracting Governments are required to issue instructions at the national level and the Chapter makes mandatory the International Maritime Dangerous Goods (IMDG) Code, developed by IMO, which is constantly updated to accommodate new dangerous goods and to supplement or revise existing provisions.
 
Part A-1 - Carriage of dangerous goods in solid form in bulk - covers the documentation, stowage and segregation requirements for these goods and requires reporting of incidents involving such goods.
 
Part B covers Construction and equipment of ships carrying dangerous liquid chemicals in bulk and requires chemical tankers to comply with the International Bulk Chemical Code (IBC Code).
 
Part C covers Construction and equipment of ships carrying liquefied gases in bulk and gas carriers to comply with the requirements of the International Gas Carrier Code (IGC Code).
 
Part D includes special requirements for the carriage of packaged irradiated nuclear fuel, plutonium and high-level radioactive wastes on board ships and requires ships carrying such products to comply with the International Code for the Safe Carriage of Packaged Irradiated Nuclear Fuel, Plutonium and High-Level Radioactive Wastes on Board Ships (INF Code).
 
The chapter requires carriage of dangerous goods to be in compliance with the relevant provisions of the International Maritime Dangerous Goods Code (IMDG Code).

Chapter VIII - Nuclear ships
Gives basic requirements for nuclear-powered ships and is particularly concerned with radiation hazards. It refers to detailed and comprehensive Code of Safety for Nuclear Merchant Ships which was adopted by the IMO Assembly in 1981.
 
Chapter IX - Management for the Safe Operation of Ships
The Chapter makes mandatory the International Safety Management (ISM) Code, which requires a safety management system to be established by the shipowner or any person who has assumed responsibility for the ship (the "Company").
 
Chapter X - Safety measures for high-speed craft
The Chapter makes mandatory the International Code of Safety for High-Speed Craft (HSC Code).
 
Chapter XI-1 - Special measures to enhance maritime safety
The Chapter clarifies requirements relating to authorization of recognized organizations (responsible for carrying out surveys and inspections on Administrations' behalves); enhanced surveys; ship identification number scheme; and port State control on operational requirements.

Chapter XI-2 - Special measures to enhance maritime security
Regulation XI-2/3 of the  chapter enshrines the International Ship and Port Facilities Security Code (ISPS Code). Part A of the Code is mandatory and part B contains guidance as to how best to comply with the mandatory requirements. Regulation XI-2/8 confirms the role of the Master in exercising his professional judgement over decisions necessary to maintain the security of the ship. It says he shall not be constrained by the Company, the charterer or any other person in this respect.
 
Regulation XI-2/5 requires all ships to be provided with a ship security alert system. ,Regulation XI-2/6 covers requirements for port facilities, providing among other things for Contracting Governments to ensure that port facility security assessments are carried out and that port facility security plans are developed, implemented and reviewed in accordance with the ISPS Code.Other regulations in this chapter cover the provision of information to IMO, the control of ships in port, (including measures such as the delay, detention, restriction of operations including movement within the port, or expulsion of a ship from port), and the specific responsibility of Companies.

Chapter XII - Additional safety measures for bulk carriers
The Chapter includes structural requirements for bulk carriers over 150 metres in length.

Amendments
The 1974 Convention has been amended many times to keep it up to date.
Amendments adopted by the Maritime Safety Committee  (MSC) are listed in MSC Resolutions. 
MARINESHELF publishes articles contributed by seafarers and other marine related sites solely for the benefit of seafarers .All copyright materials are owned by its respective authors or publishers.



FLAMMABILITY

Flammable Limits

·        A mixture of hydrocarbon gas and air cannot ignite, unless its composition lies within a range of gas-in-air concentrations known as the flammable range.
·        The lower limit of the range, known as the "lower flammable limit", is any hydrocarbon concentration below which there is insufficient hydrocarbon gas to support combustion.
·        The upper limit of the range, known as the "upper flammable limit", is any hydrocarbon concentration above which air is insufficient to support combustion.
·        The flammable limits vary somewhat for different pure HC and for the gas mixtures derived from different petroleum liquids.
·        However in practice the lower and upper flammable limits of oil cargoes carried in tankers is for general purposes taken to be 01and 10 % hydrocarbon by volume, respectively.

Flammable Range Diagram



Hydrocarbon gas/air/inert gas mixtures effect on flammability

1.     Any point on the diagram represents a hydrocarbon gas/air/inert gas mixture, specified in terms of its hydrocarbon and oxygen content.
2.     Hydrocarbon/air mixtures, without inert gas, lie on the line AB, the slope of which shows the reduction in oxygen content as the hydrocarbon content increases.
3.     Points to the left of AB represent mixtures whose oxygen content is further reduced by the addition of inert gas.

·        The flammable range for HC gas is between 1 – 10%, and for O2 between 11.5 - 21%.
·        If 10% of CH gas is introduced in air, the proportion of oxygen reduces to 21x 90/100= 18.9% (Point D)
·        When O2 is minimum (11.5%), CH gas must be at least 1.5% (Point E).
·        At 1% CH gas, the oxygen must be at least 20.8% for the mixture to be flammable (Point C).
·        If the concentration of CH gas and O2 is outside the flammable range, the mixture will not burn.   

Dilution of CH Gas

·        When we dilute a CH gasair mixture with air (concentration as at Point F) the air will slowly replace the CH gas till the mixture becomes 100% air.
·        The concentrations of CH gas and O2 will take the path F A. 
·        This passes through the flammable range. At some time during the dilution, the mixture could explode if a spark was applied.
·        We must try to avoid passing through the flammable range during this dilution with air.
·        To do this the mixture is diluted with inert gas (along the path FH) till a point H is reached which is reached below the critical dilution line. As inert gas is added to hydrocarbon/air mixtures, the flammable range progressively decreases, until the oxygen content reaches a level generally taken to be about 11 per cent by volume, at which no mixture can burn
·        This is checked by sampling and testing the atmosphere with gas measuring instruments. If now O2 (air) is let in freely, the dilution will take place along line HA.
·        This does not pass through the flammable range at any time causing no danger of fire or explosion.