Last revised: February 12, 1998

The following is reprinted from Chapter 1 of the English language version of the Danish Maritime Authority report entitled "Report on the Impact of High-Speed Ferries on the External Environment"

BACKGROUND

In these years high-speed ferries have become a much favored choice of transport system. More and more ferry routes are served by high-speed ferries. New and larger high-speed ferries. New and larger high-speed ferries are expected to replace some of the existing conventional ferry capacity. At present, a picture is emerging of the future ferry concept being a combination of high-speed ferries and traditional ferries, and that high-speed ferries will primarily be used for the conveyance of passengers and private automobiles.

The public has often used the word catamaran ferries as a synonym for high-speed ferries. The word catamaran by itself means a vessel with two slender hulls connected to a superstructure. The majority of high-speed ferries are either catamarans or hydrofoil vessels. Types of ferries such as SEMI-SWATH and WAVE-PIERCER are both catamarans. High-speed ferries are also built as traditional single-hull ships, popularly called "frigate ferries". At high speed, the shape of the hull causes the ship to sail in planning mode more or less.

The propulsion of a high-speed ferry is typically generated by high-speed diesel engines or gas turbines. Traditional propulsion by the use of propellers is often replaced by water jet systems where water is directed through intakes in the hull and pumped out via jets in the ship's stern.

During recent years, the Danish authorities have received a number of complaints about inconveniences from high-speed ferries. These complaints have included questions about noise, energy consumption, waves, speed, and water jets and their influence on the surrounding environment, as the protection of nature including animal and plant life, sailing and bathing safety, erosion of the coastline and the safety of dikes.

ESTABLISHMENT OF THE DANISH COMMITTEE

Terms of Reference - The committee was to provide suggestions for appropriate regulation of both short and long term effects of high-speed ferries on the marine environment by the end of 1996.

On October 10, 1996 a committee concerned with the effects of high-speed ferries on the marine environment was set up with a view to investigating these conditions and, if necessary, to recommending appropriate regulations regarding these problems.

When the committee was set up, there were only a few investigations into the effects of high speed ferries on the surrounding areas. During the time in which the committee has been in existence, the following material regarding high-speed ferries has been completed: a report concerning investigations of waves and erosion, a report concerning noise from high-speed ferries as well a working note from the first phase of the investigation on the disturbance to bird life caused by high-speed ferry operation near Samso. The committee has made use of the knowledge available from these investigations. In terms of disturbance to nature, there is still a need to carry out further investigations.

MEMBERS OF THE COMMITTEE

Ministry of Environment and Energy, Special Planning Department
The Danish Environmental Protection Agency
The National Environmental Research Institute
National Forest and Nature Agency
Ministry of Transport
Danish Coastal Authority
Danish Shipowners' Association
Danish Car Ferries' Association
Danish Navigators' Union
Danish Engineers' Association
Danish Metal Workers' Union
The Outdoor Council
Danish Society for the Conservation of Nature
Danish Ornithology Society - Bird Life Denmark
The Danish Council of Bathing Safety

CONCLUSIONS OF THE WORK OF THE COMMITTEE

After the committee had identified the environmental problems caused by high-speed ferries, it became clear that future regulations for such noise, air pollution and waves could be laid down by imposing objective requirements and subsequently ensuring that these requirements are observed. However, with regard to animal and plant life for example, it must be admitted that it is impossible to set down general objective criteria which satisfactorily ensure that nature is not affected unnecessarily. This is why it is necessary to conduct an assessment of each specific crossing.

The committee recommends:

• that an advance authorization scheme be introduced for the establishment of a new high-speed ferry route which includes at least one Danish port of call, as well as for the introduction of a new high-speed ferry or for a significant change in the frequency of crossings on an existing route. The authorization is to be coordinated by the Danish Maritime Authority;

• that a suitable transitional scheme be introduced for existing high-speed ferries on existing high-speed routes;

• that guidelines for noise limitations for high-speed ferries be created;

• that limitations for waves from high-speed ferries be determined on the basis of the effects waves which are generated by conventional ferries;

• that an environmental assessment involving a public hearing be introduced for routes in environmentally sensitive areas, or areas of special natural interest;

• that a closer investigation be conducted into the relationship between nitrous oxide N0_x and fuel consumption and the practical use of technical solutions which can limit the amount of nitrous oxide in exhaust gas, for use in possible future regulation of nitrous oxide in exhaust gasses from high-speed ferries.

The committee can demonstrate that the existing legislation fails to constitute a sufficient foundation for possible future regulation. The committee finds, therefore, that the necessary amendments to The Marine Environment Act and to The Coastal Protection Act should be made as soon as possible.

THE BACKGROUND FOR THE COMMITTEE'S RECOMMENDATIONS

To ensure that significant demands are not placed on a shipping company after a high-speed ferry is put into operation, an advance authorization should be applied for. This authorization should be given when:

• introducing new high-speed ferries which have at least one Danish port of call;

• establishing new routes;

• there is a significant change of routes, or changes of frequency of crossings.

For existing high-speed ferries and routes a suitable transitional scheme is to be introduced. (See section 3.8)

To relieve the shipping company of unnecessary administrative burdens and to ensure that no conflicting demands from the authorities involved are put forward, an application for permission to operate one or more high-speed ferries on a particular route is to be managed collectively, and coordinated by the Danish Maritime Authority. (See section 3.8)

The Committee finds that a full assessment of the noise sensitivity should be carried out in an area which is used by high-speed ferries. The basis of the assessment should be noise sensitivity in an area. This will ensure that advance authorization of the noise level can occur before new high-speed ferries are put into operation. (See section 3.1)

There have been no complaints about exhaust gas pollution from high-speed ferries. It is, nonetheless, the understanding of the committee that there is a need for possible future regulation to reduce nitrous oxide from high-speed ferries. Furthermore, a closer investigation should be carried out of the interdependency of the emission nitrous oxide and fuel consumption, together with practical application of N0x reducing technology. (See section 3.2)

The question of energy consumption in comparison with other forms of transport has not been discussed by the committee, as the committee is aware this question is to be addressed by the Energy Environment Council set up by the Ministry of Environment and Energy. (See section 3.2)

Waves from high-speed ferries create a particular safety problem for small vessels and leisure activities at sea and along the coasts. It is the committee's understanding that the risk of waves from high-speed ferries should not be greater than the risk of waves from conventional ferries. The committee finds, therefore, that a limit value for waves from high-speed ferries should be defined, and that the necessary control measures should be established. (See section 3.3)

The limit value for waves will generally safeguard against negative effects to coastal erosion, the safety of dikes etc. However, the Committee finds, that a full assessment of specially exposed points along the coast should be conducted.

It has been demonstrated that high-speed ferries disturb bird life more than conventional ferries. Present information does not indicate, however, that high-speed ferries create problems for seals, fish, or plankton. The committee is therefore of the opinion that an environmental assessment should be carried out - including a public hearing - for crossings where there is reason to believe that high-speed ferries can significantly disturb the environment or harm cultural monuments worthy of preservation. It must be made clear that navigation is compatible with important environmental protection interests. Where there is reason to believe that the navigation of high-speed ferries will create significant disturbance to outdoor life in contrast to equivalent navigation by conventional ferries, then the environmental assessment will be extended to include these areas. (See section 3.4)

From the information available and also from experience, there is no indication that the water jet systems or waves from high-speed ferries create erosion of the sea bed in the open sea, and the mixing effects of propulsion systems on sea water do not give the committee cause for concern. The effects in more closed waters, with less movement of the sand mass, together with possible influences on the sea bed have not bee investigated. Possible problems for harbor installations provoked by the jet systems of high-speed ferries should, as has been the case so far, be solved by the harbor authorities and the shipping company affected. (See section 3.5)

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