Survival and the Sea
217
would provide up to £4 million (the cost of British and French
Torrey Canyon operations) in compensation for oil spills. As it is,
the oil companies already spend thousands of pounds to keep oil
pollution to the absolute minimum in the neighbourhood of
reneries and quays. Another voluntary effort is the use of the
‘load—on—top’ procedure which aims to prevent the discharge of oil
at sea. After unloading, tankers ll about one—third of the cargo
tanks with water to preserve stability. In the past, before more oil
was loaded, this water ballast, along with a hundred or so tons of oil
which had stuck originally to the internal steel—work, was discharged
into the sea. However, with the load—on—top system, one tank is used
as a ‘slop tank’, receiving the water and oil washings from the ballast
tanks. The oil separates out and oats to the surface of the tank so
that eventually clean water can be run o" from the bottom into the
sea. The fresh cargo is then loaded on top of the separated oil. The
load—on—top system now operating in about 75 per cent of crude oil
shipments prevents the discharge of around 1% million tons of crude
oil per annum.
At government level the battle against oil pollution has been going
on for many years and led to the International Convention for the
Prevention of Pollution of the Sea by Oil. The Convention sets out
what constitutes an ‘0in mixture’ and details areas where such
mixtures should not be dumped. The version of the Convention in
force at the time of the T army Canyon prohibits the discharge of
persistent oil within 100 miles of most of the world’s coastlines with
a special large zone, including the North Sea, which extends out
from North—west Europe into Mid—Atlantic. The discharge of oil
by new ships of 20,000 tons and over is banned completely. Enforce—
ment of the Convention involves the framing of legislation by nations
which are signatories to it and‘an offending ship can be punished
only by the country of registration. Even if all maritime countries
had signed the Convention, which they have not, such laws are
difcult to enforce and offenders are rarely reported. Meanwhile,
some 480 million tons of crude oil and its products are carried each
year over the 0ceans, part of it in tankers with three times the
capacity of the Torrey Canyon.
Although every year thousands of sea birds, some of them rare,
die from the effects of oiled plumage, oil pollution is much more of a
menace to the amenities enjoyed by man than to marine life in
general. With sewage, the problem becomes more serious, but once
217
would provide up to £4 million (the cost of British and French
Torrey Canyon operations) in compensation for oil spills. As it is,
the oil companies already spend thousands of pounds to keep oil
pollution to the absolute minimum in the neighbourhood of
reneries and quays. Another voluntary effort is the use of the
‘load—on—top’ procedure which aims to prevent the discharge of oil
at sea. After unloading, tankers ll about one—third of the cargo
tanks with water to preserve stability. In the past, before more oil
was loaded, this water ballast, along with a hundred or so tons of oil
which had stuck originally to the internal steel—work, was discharged
into the sea. However, with the load—on—top system, one tank is used
as a ‘slop tank’, receiving the water and oil washings from the ballast
tanks. The oil separates out and oats to the surface of the tank so
that eventually clean water can be run o" from the bottom into the
sea. The fresh cargo is then loaded on top of the separated oil. The
load—on—top system now operating in about 75 per cent of crude oil
shipments prevents the discharge of around 1% million tons of crude
oil per annum.
At government level the battle against oil pollution has been going
on for many years and led to the International Convention for the
Prevention of Pollution of the Sea by Oil. The Convention sets out
what constitutes an ‘0in mixture’ and details areas where such
mixtures should not be dumped. The version of the Convention in
force at the time of the T army Canyon prohibits the discharge of
persistent oil within 100 miles of most of the world’s coastlines with
a special large zone, including the North Sea, which extends out
from North—west Europe into Mid—Atlantic. The discharge of oil
by new ships of 20,000 tons and over is banned completely. Enforce—
ment of the Convention involves the framing of legislation by nations
which are signatories to it and‘an offending ship can be punished
only by the country of registration. Even if all maritime countries
had signed the Convention, which they have not, such laws are
difcult to enforce and offenders are rarely reported. Meanwhile,
some 480 million tons of crude oil and its products are carried each
year over the 0ceans, part of it in tankers with three times the
capacity of the Torrey Canyon.
Although every year thousands of sea birds, some of them rare,
die from the effects of oiled plumage, oil pollution is much more of a
menace to the amenities enjoyed by man than to marine life in
general. With sewage, the problem becomes more serious, but once