Shipping

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Contents

1. Scope

2. Environmental impacts and protective measures

2.1 Workplace and health
2.2 Water
2.3 Air
2.4 Seabed
2.5 Ecosystems

3. Notes on the analysis and evaluation of environmental impacts

3.1 Water
3.2 Other media
3.3 Special features

4. Interaction with other sectors

4.1 Shipping administration
4.2 Ports and waterways

5. Summary assessment of environmental relevance

6. References

1. Scope

This brief deals exclusively with ocean-going ships, including special-purpose vessels, but not to self-propelled or towed marine platforms and equipment. The transport routes are the open sea, sea lanes, shipping lanes, inland waterways, and harbours. Submarine vessels and special diving equipment for technical marine tasks of inspection, exploration and similar purposes are not included, nor are warships considered.

Ships transport an extremely wide variety of cargoes, from human beings, to solid objects, to liquids and gases. Ships are also used for special purposes in ocean dumping or incineration of waste.

Because shipping is an international activity, national specifications and regulations relating to loading and safety at sea are largely based on international agreements and conventions.

Most ships are propelled by diesel engines and are fitted with diesel power generators. There are also turbine ships with oil-fired boilers, and a few coal-fired ships still exist. There is also a series of ships with gas turbines.

2. Environmental impacts and protective measures

Environmental impacts occur even if the ship is operated correctly. Accidents and human and technical errors can damage the environment to a degree that is difficult to assess. These impacts vary from case to case and should be determined in the individual case by means of a risk analysis.

Generally speaking, protective measures nearly always include

- structural
- training or
- legal and administrative measures with internationally recognised standards providing a reference for all individual measures.

One internationally recognised specification for construction standards is the set of classification regulations of the individual classification societies, some of which have been incorporated into the safety regulations enshrined in national legislation. In addition, certain fields are governed by the "International Convention for the Safety of Life at Sea (SOLAS)" and the "International Convention for the Prevention of Pollution from Ships (MARPOL)". A construction standard corresponding to the generally recognised state of the art is met when a ship is granted the appropriate class mark for its type and area of operation.

It should generally be borne in mind that any safety installation is to be deemed ineffective if adequately qualified personnel are not available.

The minimum international standard for the competence of a ship's crew is governed by the "International Convention on Standards of Training, Certification and Watchkeeping for Seafarers (STCW)". On the other hand, the actual content and duration of training vary from one country to another.

To determine the environmental impacts and protective measures of the complex system known as a "ship" it is necessary to consider a network of factors relating to the spheres of marine engineering, crewing and on-shore measures (such as technical infrastructure, suitable personnel, legal requirements etc.).

2.1 Workplace and health

Direct effects on human beings are inflicted primarily by the noise of main and auxiliary engines and machinery, and also by gaseous or other pollutant-emitting cargoes which may have an adverse effect on human health. Contamination of drinking water and foodstuffs (fish, birds) is caused by oil residues and the remains of toxic cargoes. As a rule, the former affects only crew members and passengers, although pollutant-emitting cargoes can indirectly affect third parties as well (see also 2.3 Air).

Noise-abatement measures are described in classification regulations and (in Germany) in the accident prevention regulations of the maritime employers' liability insurance association Seeberufsgenossenschaft (SBG)

The "International Maritime Organisation (IMO)" has issued recommendations for maximum noise levels in its resolution on "Noise Levels on Board Ships" (see Table I).

Table 1 - Noise-abatement measures in European maritime nations

(Values in dB)

Technically speaking, noise-abatement does not present any major problems. The engine rooms are generally enclosed and therefore allow structural noise protection to be included. Airborne noise from exhaust gas outlets on deck and in the surrounding environment can be reduced by mufflers. Other noise emissions (e.g. fans, exhaust gas noise) can be reduced by the appropriate structural measures.

Protection against pollutant emissions is achieved in the first instance by loading cargoes in accordance with the proper procedures; this requires an awareness of the particular problems involved in handling special cargoes on the part of the crew and the personnel at the ports of loading and discharge. International regulations must be observed, such as those of the "International Maritime Dangerous Goods Code (IMDG-Code)" and MARPOL -also in the shipbuilding sector - as the international standards relating to protective measures.

By installing appropriate ventilation systems in the ship's accommodation areas, the intake of air impurities can be substantially reduced.

The risk to personnel (crew and third parties) posed by the accidental release of pollutants due to collision, explosion or on-board fire may in certain cases be extreme (e.g. in the case of radioactive, highly toxic or explosive cargoes).

2.2 Water

The following can and do have an environmental impact on seawater or river water:

- oil and oil sludge and mixtures containing oil,
- cargo residues,
- operational waste from the ship (domestic refuse, engine room waste),
- waste water,
- bilge water,
- paint,
- fish waste, and
- dumping and incineration discharge.

The diesel engines on ships are powered by heavy oil, marine diesel oil, or marine gas-oil. Oil sludge occurs largely due to flushing of heavy oil and, to a lesser degree, marine diesel oil, while the problem is almost negligible in the case of marine gas-oil.

Over 90% of all ships burn heavy oil. The quality of this fuel is steadily decreasing, as it is made from crude oil residues from which as many high-quality distillates have been extracted as possible. In addition, the fuel has a high sulphur content (up to 3%). The sludge fraction in heavy oil processing on board at present amounts to about 3% of total fuel consumption.

In addition, residual oils result from oil changes on machinery and equipment.

Mixtures containing oil occur in the form of tank flushing water, bilge liquids and oily ballast water.

Under MARPOL, all liquids containing oil must, under normal operating conditions, pass into the sea only via oil separation systems, and may not do so in any circumstances in the form of sludge. The sludge and the separated oil residues are either to be incinerated on board in special furnaces or discharged in port to the oil collection facilities, though there are not enough of these available worldwide.

The most effective ways of preventing oil pollution from normal maritime operations are to ensure awareness, understanding and observance of MARPOL regulations among ships' crews, to provide adequate facilities for discharging oily residues and to carry out effective supervision and monitoring of adherence to the regulations. Machinery fuelled by marine diesel oil or marine gas-oil (both of which, incidentally, are not substantially more expensive than heavy oil) help reduce sludge to a substantial degree.

Depending on the facilities available to the individual ship for discharging oil residues at disposal facilities or incinerating them on board, it may be necessary to provide tanks for sludge and slop (flushing water containing oil). This is the case, for example, if on-shore disposal facilities in the ship's area of operations are inadequate. Recommendations are currently being prepared by the Marine Environment Protection Committee of the IMO (MEPC) for the dimensioning of such tanks.

Measures which extend beyond the international standard include, among others, the use of double-hulled vessels as tankers, doing away with pipeline systems for direct disposal, the use of detergents specifically approved by the manufacturers of the oil separation systems, economic disposal incentives and public-law prohibitions on substandard ships.

Cargo residues occur in solid or liquid form after each discharge of non-containerised cargo (e.g. damaged cargo, non-pumpable residues). The disposal of solid and liquid waste and residues is likewise governed by MARPOL.

It is advisable to avoid introducing any solid or liquid cargo residue into the water and instead to dispose of it on land. This applies both to substances which fall under MARPOL Annex III and to substances not covered by MARPOL.

With regard to chemical tankers, it should also be noted that double-hulled vessels (which should always satisfy at least the standards of IMO Type 2 ships, under the "International Code for the Construction and Equipment of Ships carrying Dangerous Chemicals in Bulk (IBC-Code)") are not only more collision-resistant, but also help reduce the volumes of residue by having smooth tank walls (in contrast to single-hulled vessels).

Since 31.12.1988, the disposal of general ship's waste has been mandatorily governed by MARPOL Annex V. The discharge of certain types of waste is however permitted in principle at distances of 12 or 25 nautical miles offshore. One measure which goes beyond the scope of MARPOL, to prevent pollution of water by refuse, is to treat the ship as a closed system. This means that all the waste and residues generated during operations are temporarily stored and handled in such a way that no pollutants whatsoever can enter the water. This includes collection of different types of refuse in separate containers, provided appropriate disposal facilities are available on shore.

The treatment and disposal of wastewater has not yet been mandatorily regulated on an international level (except for the Baltic Sea area), because MARPOL Annex IV -regulations for the prevention of contamination by ships' wastewater - has not yet come into force. Moreover, MARPOL only covers what is referred to as foul or dirty water (sanitary sewage), while grey water (such as wastewater from galleys or washing water) may be introduced untreated, even after Annex IV comes into effect.

As in the case of ship's waste, a closed circuit is recommended, which will not allow any contaminating discharge whatsoever. Faecal matter can nowadays be processed biologically, and there are waste macerators, waste presses and grease separators for wastewater from galleys.

Paint from the ship's outer skin contains toxic anti-fouling additives. Slow dissolving can contaminate the water and effective alternatives are not yet known. The Marine Environment Protection Committee of the IMO (MEPC) is however working on a way of developing environment-friendly alternatives.

Waste from fish processing at sea is not yet subject to MARPOL standards. Rather than introducing all the waste into the sea, it is possible to use on-board fishmeal systems; if these are used, only minimal quantities of waste need be discharged into the sea.

Waste dumping and incineration ships are an obvious and deliberate menace to water purity, which can only be prevented by halting such operations.

Figure 1 - Disposal methods

2.3 Air

The operation of combustion engines causes the following environmentally relevant gases to be released into the atmosphere (the air): Carbon monoxide, carbon dioxide, sulphur dioxide, hydrocarbons and nitrous oxides; soot is also emitted.

In general a distinction should be made between the following type of atmospheric emission:

- exhaust gases from engines, auxiliary engines, main and auxiliary boilers;
- gases from the cargo as a result of gas leakage or evaporation (tank respiration);
- gases from the cargo or released during loading and unloading due to

· displacement of the tank atmosphere when the tanks are filled without a gas displacement system

· removal of cargo residues due to forced ventilation of the cargo tanks

· degassing of cargo tanks.

In certain cases this may be rectified by cleaning of exhaust gases. Merely ensuring correct adjustment and maintenance of engines and boilers will limit emissions.

The energy consumption is that of the average ship of the class in question. In the case of ocean-going vessels, two figures are quoted because of the differing sulphur contents of the fuels used. It is assumed that heavy oil contains about 3% sulphur and marine diesel oil about 1%.

There are no international agreements or recommendations regarding emission limits for ships or regulations regarding the minimum fuel qualities (and thus e.g. the sulphur content). The MEPC is however working on this problem too, so as to be able to develop recommendations for international standards.

The measures specified in MARPOL Annex II (see above) are used to avoid emissions from cargo tanks on chemical tankers.

With volatile gases, appropriate measures include mechanical precautions to ensure the containment of the gases which escape during loading and discharge operations, even where these are allowed to escape under MARPOL specifications. This is particularly important in the case of substances hazardous to the global atmosphere, such as halogen compounds.

Cargoes of gas tankers which are liable to cause emissions or explosions are only subject to MARPOL II if they have a vapour pressure of max. 2.8 kp/cm² at a temperature of 37.8 degrees Celsius.

There are no international regulations governing the discharge of gases; there is however a "Code for Construction and Equipment of Ships Carrying Liquified Gases in Bulk (1983)", issued by the IMO.

On gas tankers, the evaporating gases are recondensed or incinerated wherever possible.

Incineration ships which burn chlorinated hydrocarbons are responsible for large emissions. The hydrogen chloride and certain other substances are absorbed by the sea, but dioxins and furans are also produced, and may have an adverse effect on ecosystems and water quality. Nearby coastal areas may be polluted if the winds are in the appropriate direction. No effective preventive measures are known, therefore this disposal method is not recommended.

2.4 Seabed

Ocean dumping and waste disposal has a direct environmental impact on the seabed, and an indirect effect as a result of contamination of the water with substances of higher specific gravity than seawater. Mechanical impairment may occur due to the dredging of harbours and shipping channels and, to a very small extent, due to the suction and swell effect of moving vessels.

The disposal of refuse into the sea should be banned entirely (see above).

Mechanical impairment can be reduced by restricting the draughts and speeds of shipping to a minimum.

2.5 Ecosystems

The ecosystems of the sea and rivers can suffer lasting damage due in particular to the introduction of foreign and toxic substances which accumulate in the sediments or as suspensions in the water, and pass into the food chain.

As well as coating seabirds and other sea creatures, oil also causes oxygen deficiency in oil-covered sediments and draws oxygen from the water when the oil decomposes, which may inflict secondary damage on the fauna. Large, slowly-sinking oil slicks destroy all microflora and microfauna by oxygen deprivation.

To combat sea pollution by ocean-going vessels, not only should the minimal requirements of MARPOL be taken as the basis, but also the closed-circuit system should be introduced for ships. This will prevent any substances being discharged into the sea; measures to develop and expand shipping should thus always be accompanied by appropriate on-shore infrastructural planning and installations.

3. Notes on the analysis and evaluation of environmental impacts

3.1 Water

Emissions into water are mainly the result of deliberate rule violations, accidents, technical defects or simply ignorance on the part of the crew. The long-term effects of oil and toxic chemicals from cargo components or cargo residues are a particularly serious environmental problem.

Only very limited discharge of domestic and operational waste is now permitted by law, therefore this should be eliminated altogether.

The disposal of tank flushing water, oil residues, and refuse still permitted under MARPOL regulations and the deliberate release of ventable cargo residues could be done away with if adequate receiving facilities were available, appropriate levels of training were given and requirements going beyond the scope of MARPOL were laid down, or if design improvements were introduced.

Wastewater, though not yet the subject of binding international regulations, can be treated by means of built-in treatment plants which are already available for small vessels and point the way ahead for the future.

The use of ships for the incineration and dumping of waste inflicts incalculable long-term damage on the environment (toxic effects on water and air) and must therefore be stopped.

The discharge of fishing waste into the water (high organic contamination burden) can be almost entirely eliminated by the installation of appropriate recycling systems.

3.2 Other media

Emissions from ships into the surrounding atmosphere result for the most part from exhaust gases from combustion engines and partly from emissions of chemicals and gas tankers (disregarding refuse incineration ships, dealt with under 3.1), as well as noise.

The IMO, in collaboration with the "International Standardisation Organisation (ISO)", is in the process of specifying minimum fuel qualities and formulating emission conditions.

Through design measures in conjunction with operational procedures, extending beyond the international minimum standards such as MARPOL and classification specifications, a substantial reduction in cargo emissions can be achieved, with a view to attaining a cargo yield of 100 % (i.e. without any undischargeable residues remaining on board).

3.3 Special features

Particularly serious environmental damage is caused by accidents. The environmental risk from accidents varies depending on the type of ship, its size, the nature of the cargo and the waters through which it passes. It is accordingly recommended that a risk study be carried out in the individual case, based on the special conditions which prevail, to determine the potential environmental impact.

Special attention must be paid to the transport of special cargoes:

- hazardous cargoes according to the IMDG Code,
- hazardous liquid bulk cargoes,
- crude oil and its derivatives etc.

4. Interaction with other sectors

There is direct contact with the sector of shipping administration and the sector of ports and waterways (see also the environmental brief Ports and Harbours, Navigable Waterways).

4.1 Shipping administration

Efficient ship operation, complying with all environmentally relevant design requirements and organisational measures, depends on an existing body of shipping legislation, an effective system to administer that legislation and a functioning judiciary.

Complex industries like the shipping industry can only be regulated through legislative measures introduced in a wide variety of sectors, so as to minimise environmental impacts. The following peripheral sectors may be mentioned in this regard:

- incorporation of international construction, safety and environmental regulations and codes of conduct into national law,
- labour and social legislation,
- training regulations,
- administration, police and penal provisions.

Practical implementation requires a system of administration which at least takes account of underlying needs. These include, in particular:

- technical supervision and monitoring, of the environment as well
- social supervision and monitoring
- nautical/technical planning and measures
- development, coordination and support of the necessary training courses, including those intended to raise awareness of environmental issues.

An appropriate legal system is also needed to implement and define the relevant legal consequences.

4.2 Ports and waterways

In the port sector, the following are particularly important in the interests of the environment:

- reliable and environment-friendly handling technology,
- suitable storage facilities,
- reliable and orderly delivery and removal of cargoes,
- provision of necessary waste disposal facilities,
- availability of appropriate emergency equipment and personnel (fire services, ambulances, port tugs, pilots, equipment to deal with oil and chemical accidents etc.).

To protect against accidents, navigational aids and navigation marks are required for all navigable waters of the port, shipping lanes, coastal waters and the open sea immediately outside the port.

In addition, care must be taken to ensure that minimum water depths are known and any other necessary precautionary measures are taken in coastal and open waters (speed restrictions, coastal defences, closure of protected areas etc.).

5. Summary assessment of environmental relevance

Ships can cause environmental damage particularly as a result of

- crude oil and its derivatives and combustion gases,
- hazardous solid and liquid cargoes and cargo residues,
- operational waste,
- wastewater,
- shedding of toxic paints.

For the most part, pollutants are only released into the atmosphere or water as a result of deliberate rule violations, ignorance or accident or because design specifications and/or operational procedures are not internationally binding.

If ships are designed as closed systems, with appropriate disposal facilities being provided in destination ports, both discharges and emissions can be substantially reduced.

Technical standards for ships should always take account of new developments.

Environmental damage caused by ships can be reduced to a minimum if technological and design specifications are adhered to, but also and in particular if the appropriate on-shore administrative and technical infrastructure can be guaranteed.

The impact of shipping accidents must be assessed on a case-to-case basis by means of a risk analysis specially prepared for the case in question.

6. References

1. International conventions and recommendations

Code for the Construction and Equipment of Ships Carrying Dangerous Chemicals in Bulk (BCH-Code, 1986 edition).

International Convention for the Prevention of Pollution from Ships, 1973, as modified by the Protocol of 1978 relating thereto (MARPOL 73/78) including Annex I - V.

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

International Maritime Dangerous Goods Code (IMDG-Code).

International Code for the Construction and Equipment of Ships Carrying Dangerous Chemicals in Bulk (BC-Code, 1986 edition).

International Convention on Standards of Training, Certification and Watchkeeping for Seafarers, 1978.

Noise Levels on Board Ships (IMO Resolution A. 468 (xii)).

Vorschriften für Klassifikation und Besichtigung von stählernen Seeschiffen, Kapitel 1 - 10, in jeweils aktueller Ausgabe (variiert zwischen 1971 und 1988).

2. Literature

Bruck, V.: "Bilanz des Rückstandsöls und des Schiffsmülls in der Nordsee", Referat auf der 2. Bremer-Maritim-Tagung, Bremen 1987.

EAT-Systemtechnik GmbH et al.: "Chemikalien-Slop-Entsorgung im bundesdeutschen Küstenbereich", Ottobrunn, 1986.

Ehlers, P.: "MARPOL", in: Gefährliche Ladung 1985, p. 363.

as above: "MARPOL 73/78 - Erfolg oder Mißerfolg?" in: Hansa 1990, p. 35.

Forschungsstelle für die Seeschiffahrt zu Hamburg e.V.: "Meeresverschmutzung durch den Transport wassergefährdender Stoffe auf See - Bestandsaufnahme und Maßnahmeempfehlungen", Bd.. II + V, Hamburg, 1987.

Pahl, G.: "Schiffstankreinigung und Entsorgungstransport", Referat auf der 2. Bremer-Maritim-Tagung, Bremen 1987.

Schuldt, J.: "Schwerölreinigung für Dieselmotoren durch Zentrifugal-Separatoren", in: Schiffsingenieur-Journal, 1985, Heft 11/12, p. 4.

Umweltbundesamt [German Federal Environmental Agency]: "Verschmutzung der Nordsee durch Öl und Schiffsmüll", Berlin, 1985.

Wragge, F.: "Lärmschutz auf Seeschiffen", in: Hansa 1988, p. 1498.

Wragge, F.: "Bordseitige Probleme der Entsorgung von Seeschiffen", in: Hansa, 1989, p. 1443.

3. Reports on meetings of the Marine Environment Protection Committee of the IMO (MEPC)

Ehlers, P.: Bericht über die 25. Sitzung (report on the 25th meeting), in: Hansa 1988, p. 236.

Menzel, H.: Bericht über die 27. Sitzung (report on the 27th meeting), in: Hansa 1989, p. 640.

NN: Bericht über die 26. Sitzung (report on the 26th meeting), in: Hansa 1988, p. 1423

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