220
A. NELSON-SMITH
dry-cargo bulk carriers of over 100 000 tons, designed for alternative
oil-carrying service, lack even the longitudinal bulkheads. Doubt has
been cast on the seaworthiness of some such designs if more than one
compartment should be damaged. I n these circumstances, the simplification of pumping arrangements reduces flexibility in the control of
cargo, while the development of better anti-corrosion treatments
permits the use of thinner plating, which is less resistant to violent
impacts.
Although they are capable of high speeds, all but the very largest
of modern tankers still have a single screw for reasons of economy.
Their manceuvrability in narrow waterways is necessarily restricted.
For example, “ Torrey Canyon ” was making about 16 knots when she
struck Pollard Rock and would otherwise have required at least 2
miles to come to a dead stop; other supertankers require as much as
7 miles (Wiebe, following Edwards, 1968). The turning circle of such
tankers ranges from one-half to over 2 miles. Of course, modern
navigation aids should compensate for this (see Kluss, 196813). Although
she lacked a Decca Navigator, “ Torrey Canyon’s ” radar had a range
of 40 miles. Had she been following a prescribed course, as all civil
aircraft are required to do, she would have avoided disaster. Traffic
separation is already observed, on a voluntary basis, in the Strait of
Dover and other regions of high traffic density; its operation is discussed by Dilling (1968). However, the 40 000-ton tanker “ Anne
Mildred Brravig ” was rammed by a small coaster in fog off the Elbe
estuary in 1966 when proceeding on a faultless course. The collision
was entirely the responsibility of the coaster, yet such small craft
would not be subject to the proposed controls (see Brockis, 1967).
Further preventive and remedial measures are discussed in a U.S.
Congress Committee Report (1967).
Measures which can be taken to control pollution after accidental
damage has occurred depend, of course, on the severity of the accident.
A tanker still having her own power may be able to move off towards
repair facilities or the open sea and might well have surplus tank
capacity into which she could pump oil from the damaged compartment. Even when a stranded vessel is stuck fast, it is rarely necessary
to jettison oil overboard in order to avoid immediate disaster. Unfortunately, the value of the ship is invariably much greater than that of the
cargo and current salvage contracts provide no reward for the avoidance
of pollution. The possibilities of pumping the cargo into an empty
tanker standing off the wreck were well demonstrated when the “ Esso
Margarita ” successfully received over 15 000 tons of the 18 000 tons
of fuel-oil carried by the “ General Colocotronis ”, which ran onto a
A. NELSON-SMITH
dry-cargo bulk carriers of over 100 000 tons, designed for alternative
oil-carrying service, lack even the longitudinal bulkheads. Doubt has
been cast on the seaworthiness of some such designs if more than one
compartment should be damaged. I n these circumstances, the simplification of pumping arrangements reduces flexibility in the control of
cargo, while the development of better anti-corrosion treatments
permits the use of thinner plating, which is less resistant to violent
impacts.
Although they are capable of high speeds, all but the very largest
of modern tankers still have a single screw for reasons of economy.
Their manceuvrability in narrow waterways is necessarily restricted.
For example, “ Torrey Canyon ” was making about 16 knots when she
struck Pollard Rock and would otherwise have required at least 2
miles to come to a dead stop; other supertankers require as much as
7 miles (Wiebe, following Edwards, 1968). The turning circle of such
tankers ranges from one-half to over 2 miles. Of course, modern
navigation aids should compensate for this (see Kluss, 196813). Although
she lacked a Decca Navigator, “ Torrey Canyon’s ” radar had a range
of 40 miles. Had she been following a prescribed course, as all civil
aircraft are required to do, she would have avoided disaster. Traffic
separation is already observed, on a voluntary basis, in the Strait of
Dover and other regions of high traffic density; its operation is discussed by Dilling (1968). However, the 40 000-ton tanker “ Anne
Mildred Brravig ” was rammed by a small coaster in fog off the Elbe
estuary in 1966 when proceeding on a faultless course. The collision
was entirely the responsibility of the coaster, yet such small craft
would not be subject to the proposed controls (see Brockis, 1967).
Further preventive and remedial measures are discussed in a U.S.
Congress Committee Report (1967).
Measures which can be taken to control pollution after accidental
damage has occurred depend, of course, on the severity of the accident.
A tanker still having her own power may be able to move off towards
repair facilities or the open sea and might well have surplus tank
capacity into which she could pump oil from the damaged compartment. Even when a stranded vessel is stuck fast, it is rarely necessary
to jettison oil overboard in order to avoid immediate disaster. Unfortunately, the value of the ship is invariably much greater than that of the
cargo and current salvage contracts provide no reward for the avoidance
of pollution. The possibilities of pumping the cargo into an empty
tanker standing off the wreck were well demonstrated when the “ Esso
Margarita ” successfully received over 15 000 tons of the 18 000 tons
of fuel-oil carried by the “ General Colocotronis ”, which ran onto a