DHT - Double-hulled tankers

    TAN Dubbelwandige tankers

    The initiative to regulate the double-hull oil tankers fits in the frame of a series of measures taken by the Commission in reaction to the Erika oil disaster in December 1999.

    Up to then, most oil tankers had a single hull design. In such vessels, oil in cargo tanks is separated from seawater only by a bottom and a side plate. Should this plate be damaged as a result of collision or stranding, the content of the cargo tanks risks spilling into the sea and causing severe pollution. An effective way of avoiding this risk is to surround the cargo tanks with a second internal plate at a sufficient distance from the external plate. This design, known as double hull, protects cargo tanks against damage and thus reduces the risk of pollution.

    Following the Exxon Valdez accident in 1989, the United States (US), dissatisfied with the ineffectiveness of the international standards on the prevention of pollution from ships, adopted the 'Oil Pollution Act of 1990' (OPA '90). This unilateral act imposed double hull requirements on both new and existing oil tankers. For some vessels an age limit was installed and deadlines were conceived to ban single-hull tankers from US waters.

    Faced with this unilateral measure on the part of the Americans, the International Maritime Organisation (IMO) had to take action and established double-hull standards in 1992 in the International Convention for the Prevention of Pollution from Ships (MARPOL). This convention requires all oil tankers with a deadweight tonnage (DWT) of 600 tonnes or more delivered as from July 1996 to be constructed with a double-hull or an equivalent design. There are therefore no longer any single hull tankers of this size that have been constructed after this date. For single-hull tankers with a 20,000 DWT or more and delivered before 6 July 1996, the convention requires that they comply with the double-hull standards at the latest by the time they are 25 or 30 years old, depending on whether they have segregated ballast tanks or not.

    Given that it is difficult to transform a single-hull oil tanker into a double-hull tanker, both the American system and the MARPOL Convention lead to a phasing-out of single-hull oil tankers. Nevertheless, the differences between the American system and the international system meant that single-hull oil tankers would be banned from US waters faster than anywhere else. As a consequence, these ships would begin to operate in other parts of the world, including the European Union, and would increase the risk of pollution in the areas concerned.

    Confronted with this situation, the European Commission believed it was necessary to make haste in replacing single-hull oil tankers by double-hull tankers or ships with equivalent safety norms.

    On 27 March 2002, Regulation (EC) No. 417/2002 on the accelerated phasing-in of double-hull or equivalent design requirements for single-hull oil tankers and repealing Council Regulation (EC) No. 2978/94 was published (DHT-001). Due to this Regulation, single-hull oil tankers were, in function of their category and age, banned from European ports, terminals and anchor. In 2015, single-hull oil tankers shall no longer be allowed.
     
    In reaction to the oil disaster of the oil tanker "Prestige" in November 2002 off the coast of Galicia (Spain), the Commission wanted to improve the safety at sea and to prevent pollution from ships by speeding up the above mentioned actions. The Commission proposed to amend the existing Regulation 417/2002 in three areas:

    1. Implementing a provision that would allow the transport of heavy and dangerous types of oil only if they are transported by double-hull tankers (after 4 April 2005);
    2. Revising existing Regulations on banning certain tankers (speeding up the process);
    3. Broadening the scope of the special rules of certification for tankers which concern the structural integrity of single-hull oil tankers over 15 years old.

    These and other amendments were introduced thanks to different Regulations (DHT-002, DHT-003 and DHT-004). The last Regulation was due to amendments in the MARPOL convention.

    On 27 March 2006, the European Commission proposed an even greater acceleration. This led, after all the classical procedures, to Regulation (EC) No 457/2007 amending Regulation (EC) No 417/2002 on the accelerated phasing-in of double-hull or equivalent desig which was approved by the European Parliament and the Council on 25 April 2007  (DHT-005).

    Some relevant documents:
    DHT-005: Regulation (EC) No 457/2007 of the European Parliament and of the Council of 25 April 2007 amending Regulation (EC) No 417/2002 on the accelerated phasing-in of double-hull or equivalent design requirements for single-hull oil tankers (European Parliament and the Council)

    DHT-004: Commission Regulation (EC) No 2172/2004 of 17 December 2004 amending Regulation (EC) No 417/2002 on the European Parliament and of the Council on the accelerated phasing-in of double-hull or equivalent design requirements for single-hull oil tankers (European Parliament and the Council)

    DHT-003: Regulation (EC) No 1726/2003 of the European Parliament and of the Council of 22 July 2003 amending Regulation (EC) No 417/2002 on the accelerated phasing-in of double-hull or equivalent design requirements for single-hull oil tankers (European Parliament and the Council)

    DHT-002: Regulation (EC) No 2099/2002 of the European Parliament and of the Council of 5 November 2002 establishing a Committee on Safe Seas and the Prevention of Pollution from Ships (COSS) and amending the Regulations on maritime safety and the prevention of pollution from ships (European Parliament and the Council)

    DHT-001: Regulation (EC) No 417/2002 of the European Parliament and of the Council of 18 February 2002 on the accelerated phasing-in of double hull or equivalent design requirements for single hull oil tankers and repealing Council Regulation (EC) No 2978/94 (European Parliament and the Council)