Extended Dry Dock

Luxembourg considers requests to extend vessel dry dock periods on a case by case basis


SOLAS and Classification Society Regulations provide that a minimum of two inspections of the outside of a ship’s bottom should be held during the 5 year validity period of the Safety Construction Certificate.

SOLAS Chap. I/10(v) does not specify whether the minimum of two inspections of the outside of the ship’s bottom required during the Safety Construction Certificate’s 5-year validity period must be performed while the vessel is dry-docked out of the water.

IMO Assembly Resolution A.Res.1120(30), Survey Guidelines for the Harmonized System of Survey and Certification, provides that inspections of the outside of the ship’s bottom should normally be carried out with the ship in a dry dock. It also provides that an Administration may give consideration to alternate inspections being carried out with the ship afloat and special consideration should be given before ships of 15 years of age and over, other than bulk carriers and oil tankers, are permitted to have such surveys afloat.

A.Res.1120(30), further provides that inspection of the outside of the ship’s bottom of bulk carriers and oil tankers of 15 years of age and over should be carried out with the ship in dry dock. Inspections with the ship afloat should only be carried out when the conditions are satisfactory and the proper equipment and suitably trained staff is available.

Hull coatings have advanced over the years and new products are available that are more durable and long lasting, thus reducing the need for frequent dry docking to maintain and repaint. However, these coatings may have criteria such as vessel activity level and speed in relation to their longevity and continued effectiveness.

Pilot schemes which extend the interval between out of water dry-docking surveys are normally tripartite projects between the Owner, Flag Administration and the Classification Society.

Acceptance into such a Pilot scheme is subject to the formal written agreement with the ship’s Flag Administration including any additional specific Flag Administration requirements.


An Extended Dry Dock (EDD) scheme allows a qualified ship to be dry-docked at seven and a half year intervals, rather than the regular 5 year intervals, provided two consecutive alternate in water surveys (IWS) are satisfactorily conducted during the intervening period.

The scheme starts either from when the ship is new or at the latest, its 10 year dry-docking survey and continue until the ship reaches 15 years of age. The program can possibly be extended until a ship reaches 20 years of age, subject to satisfactory service experience.

Eligibility is contingent on Luxembourg Maritime Administration and Recognised Organisation approval.

Eligible ships must comply with the in-water survey provisions in accordance with Recognized Organization requirements.

Preparatory Reviews

The following preparatory review should be conducted prior to applying for the scheme

  • Service experience to-date, including findings from previous dry-docking and IWS with high resistant hull coating systems with proven long-lasting and durable qualities. Details from coating manufacturer regarding suitability of coating for extended period;
  • Service experience to-date with the applicable rudder and stern bearing arrangements to indicate access for measurement in water;
  • Maintenance required on sea connections at the present 1st, 2nd and 3rd cycle dry-dockings and IWS. Blanking arrangements required to be available for surveys to continue at 5 yearly intervals;
  • Condition of anchor chain cable ranged at the 2nd and 3rd cycle of dry-dockings and chain lockers;
  • Maintenance required on thrusters and stabilizers at the present 1st, 2nd and 3rd cycle dry-dockings. For thrusters: makers service intervals and actual running hours;
  • Maintenance required on electric/electronic sensors e.g. Echo-sounder, Doppler-Log, Speedlog, including findings from previous dry-docking and IWS (propeller speedlog or backpressure speedlog), seawater temperature gauges, electronic draught reading, etc.;
  • Condition of draught marks fore, aft and midships as well as Loadline mark (paint and welded figures).

Request Procedure

Shipowners/Operators must submit complete an EDD Questionnaire and submit an EDD application and in-water survey plan for review.

The following information should be provided in the application:

  • Latest Recognized Organization’s Status of Survey Report;
  • ISM Code compliance record, including any safety management system non-conformities relating to hull maintenance and any associated corrective action(s);
  • Any hull related deficiencies identified in previous Flag State or PSC inspection reports;
  • Details of any damage to the vessel’s bottom and underwater external parts for at least the last 3 years or last bottom survey in dry dock in way of the cargo hold and ballast tanks areas and void spaces within the cargo area;
  • Condition and survey history of equipment (ex. Anchors and chain cables);
  • Condition of water ballast tank coatings;
  • Coating and corrosion protection system, including anodes and previous class notations;
  • Coating manufacturer and specifications (including criteria for extended longevity of coating(s));
  • Previous in-water survey(s) and docking survey(s) reports;
  • Details of proposed in-water survey;
  • Description of arrangement for taking clearances of rudder and stern tube in Water;
  • Latest survey history of rudder clearance, poker gauge measurement and status of oil gland;
  • Description of the blanking arrangement for sea connections;
  • Description of the screw shaft arrangement and monitoring system.

Management of In-Water Surveys

An in-water survey plan detailing internal structural examinations. cargo tank internal surveys and all incidents and defects affecting underwater parts should be drawn up and approved by the Classification Society. The plan should include the following:

  • Scheduled time and location for survey;
  • Name of approved diving company;
  • Means for cleaning of the hull below waterline;
  • Provisions for surveying and maintaining sea connections including thickness measurements of sea chests;
  • Results of inspections by the Owner’s personnel of double bottom/double side ballast tanks (during the last 3 years) and other spaces adjacent to the shell with reference to structural deterioration in general, leakages in tank boundaries and piping and condition of the protective coating;
  • Details of internal structural examinations, cargo tank internal surveys and all incidents and defects affecting underwater parts;
  • Conditions for internal examination of double bottom/double side ballast tanks (e.g., information regarding tank cleaning, gas freeing, ventilation, lighting, etc.).

A survey planning meeting is held prior to commencement of the in-water survey where the attending surveyor(s), the owner’s representative in attendance, the diving company and the master of the ship or an appropriate representative appointed by the owner to confirm all the arrangements envisaged in the survey plan are in place, so as to ensure the safe and efficient conduct of the survey work to be carried out.

A comprehensive report of findings, gaugings, clearances and any work undertaken, including recordings of representative CCTV images, must be submitted by the ship owner to all involved parties.

If an IWS reveals damage or deterioration that needs early attention the owner may be required to arrange for the ship to be dry docked in order that the necessary additional inspections and repair works can be carried out.