Convention for the prevention of pollution from ships (MARPOL)
With the development of bulk shipping and the carriage of very large quantities of
toxic materials by sea, marine pollution has increasingly become the subject of
international regulations. The process of developing legislation started with a
conference held in London in 1952, and this led to the 1954 Convention for the
Prevention of Pollution of the Sea by Oil (OILPOL). The problem addressed by
the convention was that, when oil tankers carry ballast water in their cargo tanks
that they then discharge to reload cargo, it inevitably contains a certain amount of
crude oil, which pollutes the sea. The convention established ‘prohibited zones’
extending at least 50 miles from the nearest land. These regulations were
progressively updated during the next 20 years.
As the pressure on the marine environment increased during the 1960s, the need
was seen for a more broadly based convention on marine pollution, and in 1973 the
International Convention for the Prevention of Pollution from Ships (MARPOL)
was adopted. This convention deals with all forms of marine pollution except the
disposal of land-generated waste. It covers such matters as: the definition of violation;
certificates and special rules on the inspection of ships; enforcement; and reports on
incidents involving harmful substances. For example, tankers must be fitted with oil
discharge and monitoring equipment, and they must have slop tanks. New oil tankers
of over 70,000 dwt must be provided with segregated ballast tanks of sufficient
capacity to enable them to operate on ballast voyages without using oil tanks for
water ballast except in very severe weather conditions. At the next international
conference on tanker safety and pollution prevention in 1978 additional measures
were added in the form of a protocol to the 1973 convention. The lower limit for
tankers to be fitted with segregated ballast tanks was reduced from 70,000 dwt to
20,000 dwt and existing tankers were required to fit crude oil washing equipment.
In the early 1990s attention turned to measures to reduce the spillage of oil in
the event of a tanker collision or grounding. Annex I to MARPOL (73/78) included
two regulations, adopted on 1 July 1992, concerning the construction standards
for new tankers (Regulation 13F) and upgrading the safety standards of existing
tankers (Regulation 13G).
Regulation 13F deals with the design of new ships. Tankers ordered after 6 July
1993 are required to have a double hull or an equivalent, though unspecified,
design. Attention is given to the precise design of the double hull, particularly the
requirement that vessels over 30,000 dwt must have a two-metre space between
the cargo tanks and the hull. Regulation 13G was even more controversial because
it deals with existing ships. As adopted, Regulation 13G creates two age ‘hurdles’
for tankers. At 25 years tankers must allocate 30 per cent of the side or the bottom
area of the vessel to cargo-free tanks. This is a defensive measure against oil spills.
At 30 years of age all tankers must comply with Regulation 13 F and fit a double
hull.
The international convention for the prevention of pollution from ships as
modified by the Protocol of 1978 relating thereto has been ratified by 97 states.