safety - preventing accidental pollution
major function is to make shipping of all types safer, including tankers.
The measures incorporated in the numerous safety conventions and recommendations
apply to these as well as other ships - and the safer a ship is, the less likely
it is to be involved in an accident.
In this section:
Inert gas systems
Mandatory towing arrangements
MARPOL 73/78 - Reducing the consequences of accidents
Protective location, segregated ballast tanks
Single-hull phase-out timetable
Condition Assessment Scheme (CAS)
of heavy grade oil
of Annex I of MARPOL
Mandatory ship reporting systems
The Erika incident
The Prestige incident
Convention for the Safety of Life at Sea (SOLAS), 1974 includes special
requirements for tankers. Fire safety provisions, for example, are much
more stringent for tankers than ordinary dry cargo ships, since the danger of
fire on board ships carrying oil and refined products is much greater.
It is not
just fire which is dangerous - in certain circumstances a single spark can cause
a disaster, for even tanks which contain no oil are filled with flammable gas
which can explode unless proper procedures are followed.
method is to fill these tanks with inert (non-explosive) gas from the ship's
boiler flue: it is cleaned and then pumped into the empty tanks, or into the
spaces left above the oil in loaded tanks. An inert gas system is required
on all new tankers and most existing tankers of 20,000 dwt and above.
introduced several measures over the years which are designed to ensure that,
in the event of mechanical failure, the ship can still be controlled. SOLAS
makes it necessary for essential parts of the steering gear of tankers to be
As with other
ships, much of the navigational equipment of tankers must also be duplicated.
January 1996 all new tankers of 20,000 dwt and above have had to be fitted with
an emergency towing arrangement fitted at either end of the ship. Existing ships
had to be fitted with such an arrangement not later than 1 January 1999.
73/78 - Reducing the consequences of accidents
Convention for the Prevention of Pollution by Ships (MARPOL 73/78) includes regulations
regarding subdivision and stability which are designed to ensure that, in any
loading conditions, the ship can survive after being involved in a collision
location of segregated ballast tanks
The 1978 MARPOL
Protocol introduced the concept known as protective location of segregated ballast
tanks. This means that the ballast tanks (which are empty on the cargo-carrying
leg of the voyage and only loaded with water ballast for the return leg) are
positioned where the impact of a collision or grounding is likely to be greatest.
In this way the amount of cargo spilled after such an accident will be greatly
The 1983 MARPOL
amendments ban the carriage of oil in the forepeak tank - the ship's most vulnerable
point in the event of a collision.
MARPOL was amended to make it mandatory for tankers of 5,000 dwt and more ordered
after 6 July 1993 to be fitted with double hulls, or an alternative design approved
by IMO (Regulation 13F (regulation 19 in the revised Annex I which entered into force on 1 January 2007) in Annex I of MARPOL 73/78).
for double hulls that applies to new tankers has also been applied to existing
ships under a programme that began in 1995 (Regulation 13G (regulation 20 in the revised Annex I which entered into force on 1 January 2007) in Annex I of MARPOL
73/78). All tankers would have to be converted (or taken out of service)
when they reached a certain age (up to 30 years old). This measure was adopted
to be phased in over a number of years because shipyard capacity is limited
and it would not be possible to convert all single hulled tankers to double
hulls without causing immense disruption to world trade and industry.
the double hull requirement was adopted in 1992, following the Erika incident
off the coast of France in December 1999, IMO Member States discussed proposals
for accelerating the phase-out of single hull tankers. As a result, in April
2001, IMO adopted a revised phase-out schedule for single hull tankers, which
entered into force on 1 September 2003 (the 2001 amendments to MARPOL 73/78).
The new revised
MARPOL regulation 13G set out a stricter timetable for the phasing-out of single-hull
December 2003, further revisions to 13G (regulation 20 in the revised Annex I which entered into force on 1 January 2007) were made, accelerating further
the phase-out schedule. These amendments entered into force on 5 April 2005.
A new Regulation on the prevention of oil pollution from oil tankers when carrying
heavy grade oil (HGO) banned the carriage of HGO in single-hull tankers of 5,000
tons dwt and above after the date of entry into force of the regulation (5 April
2005), and in single-hull oil tankers of 600 tons dwt and above but less than
5,000 tons dwt, not later than the anniversary of their delivery date in 2008.
phase-out for single-hull tankers
Under the revised regulation 13G (regulation 20 in the revised Annex I which entered into force on 1 January 2007) of Annex I of MARPOL, the final phasing-out
date for Category 1 tankers (pre-MARPOL tankers) was 2005. The final phasing-out
date for category 2 and 3 tankers (MARPOL tankers and smaller tankers) was brought
forward to 2010, from 2015.
timetable for the phasing out of single-hull tankers is as follows:
of oil tanker
1 - oil tankers of 20,000 tons deadweight and above carrying crude
oil, fuel oil, heavy diesel oil or lubricating oil as cargo, and of 30,000
tons deadweight and above carrying other oils, which do not comply with
the requirements for protectively located segregated ballast tanks (commonly
known as Pre-MARPOL tankers)
April 2005 for ships delivered on 5 April 1982 or earlier
Anniversary date in 2005 for ships delivered after 5 April 1982
2 - oil tankers of 20,000 tons deadweight and above carrying crude
oil, fuel oil, heavy diesel oil or lubricating oil as cargo, and of 30,000
tons deadweight and above carrying other oils, which do comply with the
protectively located segregated ballast tank requirements (MARPOL tankers)
Category 3 - - oil tankers of 5,000 tons deadweight and above but
less than the tonnage specified for Category 1 and 2 tankers
April 2005 for ships delivered on 5 April 1977 or earlier
date in 2005 for ships delivered after 5 April 1977 but before 1 January
Anniversary date in 2006 for ships delivered in 1978 and 1979
Anniversary date in 2007 for ships delivered in 1980 and 1981
Anniversary date in 2008 for ships delivered in 1982
Anniversary date in 2009 for ships delivered in 1983
Anniversary date in 2010 for ships delivered in 1984 or later
Assessment Scheme (CAS)
the revised regulation, the Condition
Assessment Scheme (CAS) is applicable to all single-hull tankers of 15
years, or older.
regulation allows the Administration (flag State) to permit continued operation
of category 2 or 3 tankers beyond 2010 subject to satisfactory results from
the CAS, but the continued operation must not go beyond the anniversary of the
date of delivery of the ship in 2015 or the date on which the ship reaches 25
years of age after the date of its delivery, whichever is earlier.
In the case
of certain Category 2 or 3 oil tankers fitted with only double bottoms or double
sides not used for the carriage of oil and extending to the entire cargo tank
length or double hull spaces, not meeting the minimum distance protection requirements,
which are not used for the carriage of oil and extend to the entire cargo tank
length, the Administration may allow continued operation beyond 2010, provided
that the ship was in service on 1 July 2001, the Administration is satisfied
by verification of the official records that the ship complied with the conditions
specified and that those conditions remain unchanged. Again, such continued
operation must not go beyond the date on which the ship reaches 25 years of
age after the date of its delivery.
of heavy grade oil
A new MARPOL regulation 13G (regulation 21 in the revised Annex I which entered into force on 1 January 2007) on the prevention of oil pollution from oil tankers
when carrying heavy grade oil (HGO) bans the carriage of HGO in single-hull
tankers of 5,000 tons dwt and above after the date of entry into force of the
regulation (5 April 2005), and in single-hull oil tankers of 600 tons dwt and
above but less than 5,000 tons dwt, not later than the anniversary of their
delivery date in 2008.
new regulation, HGO means any of the following:
oils having a density at 15ºC higher than 900 kg/m3;
having either a density at 15ºC higher than 900 kg/ m3 or a kinematic
viscosity at 50ºC higher than 180 mm2/s;
to "fuel oils" was amended in 2006 to read: "oils, other
than crude oils,". This amendment enters into force on 1 August 2007)
tar and their emulsions.
In the case of
certain Category 2 or 3 tankers carrying heavy grade oil as cargo, fitted only
with double bottoms or double sides, not used for the carriage of oil and extending
to the entire cargo tank length, or double hull spaces not meeting the minimum
distance protection requirements which are not used for the carriage of oil
and extend to the entire cargo tank length, the Administration may allow continued
operation of such ships beyond 5 April 2005 until the date on which the ship
reaches 25 years of age after the date of its delivery.
13G (regulation 21 in the revised Annex I which entered into force on 1 January 2007) also allows for continued operation of oil tankers of 5,000 tons dwt and
above, carrying crude oil with a density at 15ºC higher than 900 kg/ m3
but lower than 945 kg/ m3, if satisfactory results of the Condition Assessment
Scheme warrant that, in the opinion of the Administration, the ship is fit to
continue such operation, having regard to the size, age, operational area and
structural conditions of the ship and provided that the continued operation
shall not go beyond the date on which the ship reaches 25 years after the date
of its delivery.
may allow continued operation of a single hull oil tanker of 600 tons deadweight
and above but less than 5,000 tons deadweight, carrying heavy grade oil as cargo,
if, in the opinion of the Administration, the ship is fit to continue such operation,
having regard to the size, age, operational area and structural conditions of
the ship, provided that the operation shall not go beyond the date on which
the ship reaches 25 years after the date of its delivery.
of a Party to the present Convention may exempt an oil tanker of 600 tons deadweight
and above carrying heavy grade oil as cargo if the ship is either engaged in
voyages exclusively within an area under the Party's jurisdiction, or is engaged
in voyages exclusively within an area under the jurisdiction of another Party,
provided the Party within whose jurisdiction the ship will be operating agrees.
The same applies to vessels operating as floating storage units of heavy grade
A Party to
MARPOL 73/78 shall be entitled to deny entry of single hull tankers carrying
heavy grade oil which have been allowed to continue operation under the exemptions
mentioned above, into the ports or offshore terminals under its jurisdiction,
or deny ship-to-ship transfer of heavy grade oil in areas under its jurisdiction
except when this is necessary for the purpose of securing the safety of a ship
or saving life at sea.
of Annex I of MARPOL
The revised MARPOL
Annex I Regulations for the prevention of pollution by oil was adopted in October
2004 and entered into force on 1 January 2007. It incorporates the various amendments
adopted since MARPOL entered into force in 1983, including the amended regulation
13G (regulation 20 in the revised Annex) and regulation 13H (regulation 21 in
the revised annex) on the phasing-in of double hull requirements for oil tankers.
It also separates, in different chapters, the construction and equipment provisions
from the operational requirements and makes clear the distinctions between the
requirements for new ships and those for existing ships. The revision provides
a more user-friendly, simplified Annex I.
entry into force, on 1 January 2007, of the Revised Annex I to MARPOL 73/78,
references to regulations regaarding double hulls must be updated taking into
account the new numbering system in the revised Annex I according to the following
For a comprehensive
cross-reference table between "old" and "new" regulation
numbers in MARPOL Annex I, please refer to MEPC/Circ.421
(also included in the Additional Information section of the 2006 consolidated
edition of MARPOL (IMO
all tankers and bulk carriers aged five years and over have been subject to
a specially enhanced inspection programme which is intended to ensure that any
deficiencies - such as corrosion or wear and tear resulting from age or neglect
- are detected.
on enhanced surveys on tankers and bulk carriers are contained in Assembly resolution
A. 744 (18), adopted in November 1993, as amended.
January 1996, Governments have been able to propose to IMO the introduction
of mandatory ship reporting systems in areas where there are special environmental
or navigational concerns.
systems require ships to report in to shore authorities when they reach a designated
routeing system and give the ship's name, cargo and other information. This
enables the ship to be identified on radar and its course plotted throughout
2000, IMO adopted mandatory requirements for the carriage of automatic
identification systems (AISs) capable of providing information about the ship
to other ships and to coastal authorities automatically. The regulation in SOLAS
chapter V – Safety of Navigation, requires AIS to be fitted aboard all
ships of 300 gross tonnage and upwards engaged on international voyages, cargo
ships of 500 gross tonnage and upwards not engaged on international voyages
and passenger ships irrespective of size built on or after 1 July 2002.
(those constructed before 1 July 2002), had to fit AIS not later than the first
survey for safety equipment on or after 1 July 2003.
Regulations for the Prevention of Collisions at Sea, 1972 (COLREGS) contains special
provisions for ships such as tankers which, by virtue of their draught, have
a reduced ability to manoeuvre.
Convention on Standards of Training, Certification and Watchkeeping for Seafarers,
1978, as amended in 1995 (STCW) includes several
requirements aimed specifically at those working on tankers.
Safety Management (ISM) Code was adopted in 1994 and
became mandatory for tankers in 1998. The ISM Code imposes strict standards
on shipping companies.
of the Erika off the coast of France in December 1999 led to a new, accelerated
phase-out schedule for single-hull tankers - the revision of regulation
13G (regulation 20 in the revised Annex I which entered into force on 1 January 2007) of MARPOL 73/78.
into the Erika incident carried out by the French government and the
Maltese maritime authority concluded that age, corrosion, insufficient maintenance
and inadequate surveys were all strong contributing factors to the structural
failure of the ship.
a wide consensus that the Erika and other the recent accidents involving
oil tankers pointed to a need for additional international measures to eradicate
substandard vessels, particularly substandard oil tankers given the catastrophic
impact such ships may have on the marine environment in the case of an accident.
revised phase-out scheme for single-hull tankers, IMO also adopted other measures
in response to the incident:
incident of November 2002 led to further calls for amendments to the phase-out
schedule for single hull tankers.
at its 49th session in July 2003 agreed to an extra session of the Committee,
to be convened in December 2003, to consider the adoption of proposals for an
accelerated phase-out scheme for single hull tankers, along with other measures
including an extended application of the Condition Assessment Scheme (CAS) for
see latest summary reports of the Marine Environment Protection Committee (MEPC)
and Maritime Safety Committee (MSC).
Resources on current topics
Resources on double hull/single hull ship design and related topics
Resources on the Prestige
Resources on the Erika incident and the revision of Regulation 13G (regulation 20 in the revised Annex I which entered into force on 1 January 2007) of MARPOL
safety - preventing accidental pollution
to oil spills