Main class hull surveys

Information about planned scope prior to survey has been a priority for DNV to avoid additional cost of unplanned activities in the yard. The survey is safer and more efficient, for all parties, if relevant compartments are ventilated and prepared for survey. If the majority of the scope is covered early, we allow more time for repairs within scheduled slot at the yard, consequently good preparations may avoid costly delays.

Relevant Main class hull surveys are listed in status and by expanding e.g. “main class hull renewal” survey you will find the remaining scope. The remaining scope is calculated for the applicable period, and previous records combined with e.g. actual operation and weather data is considered to select the best way to plan the required scope

The type of scope for each compartment is presented as follows:

• HOV = Hull compartment overall examination
• HTS = Hull compartment pressure/tightness test
• HTM = Hull structure thickness measurement
• HCU = Hull structure close-up examination

It is possible to propose adjustments to the planned scope by using the chat function in the request. This is useful e.g. for cases where only a part-held survey is planned. It is also possible to discuss the scope with the surveyor onboard. There are other scenarios where the scope might change or increase, e.g. due to conditions observed onboard, required surveys which must be decided by attending surveyor, part-held surveys in progress. This will be explained by the attending surveyor.

For further planning and identification of any areas of special interest, visit Hull Insights.

Hull surveys process:

• Select relevant Main class hull survey in scope
• The system populates planned hull items remaining to complete the survey at the time of the request
• If the intention is part-held only, or if there are other changes suggested; please use the Survey request chat to communicate this prior to the survey or alternatively during the kick-off meeting onboard

Note: For intermediate surveys, when only “representative hull items” are required by the Rules, no remaining hull items are listed in “Status”. Final scope is then agreed together with the attending surveyor.

 

Main class hull continuous

The hull continuous scheme is an option for vessels (other than ESP) according to DNV Rules Pt.7 Ch.1 Sec.7 [2] and IACS UR Z6. The continuous scheme has distributed the hull scope over the five-year class period and provide an improved overall assessment of the actual condition of a vessel.

Main class hull continuous is shown as a “main class hull annual” survey.

Instead of dictating the annual scope based on last inspection dates for all hull items, the introduction of the “Main class hull annual” survey increases the flexibility with respect to the annual required scope. As the system calculates what is required scope for any given 5-year class period, the system has full control on actual surveyed scope vs. scope required by the rules. It is possible to cover more of the scope in a given year and through that reduce the scope for remaining years.

The main class hull annual survey is due in conjunction with the main class annual survey, and the system is automatically distributing the scope of hull items, considering the age of the vessel and corresponding rule requirements. The system calculates at any time, during a 5-year class period, the remaining scope according to the following rules:

• For all vessels, the items in the hull survey plan established for the vessel are subject to separate surveys once in each five (5) year period. 20% of these surveys should be carried out each year in conjunction with the mandatory class annual survey, as far as practicable
• For vessels over 10 years of age, ballast tanks and tanks used for sewage (black water) and/or wastewater (grey water), are subject to separate surveys twice in each five (5) year period. Respective items will be included in the hull survey plan established for the vessel. 40% of these surveys should be carried out each year in conjunction with the mandatory class annual survey, as far as practicable

The remaining scope required by rules to be inspected, each individual year of the 5-year class period, is at any time reflected in the status:

 

 In the current system, only the list of remaining items is presented in the portal, i.e. visible to our customers. However, information as e.g. which rules has been triggered, months since last credited and complete list of hull items are available for our surveyors in their production tool:

 

Until, this information has been incorporated in the portal view, our customers may approach attending DNV surveyor to view the hull survey plan together, for better understanding of the system and the required scope.

It is in the current system, both in the portal and in DNV surveyors’ production tool, only possible to view the annual scope for any subject vessel, not the complete required plan for the 5-year class period. This will be updated in later versions of the system, for even better overview and planning of required rule scope.

By introducing separate main class hull surveys, the following should be noted for vessels on continuous scheme:

 

• Allows for commencement of the required survey scope at any time during the annual window
• The remaining scope for the 5-year class period will be automatically distributed by the system. Hence, in case
  - some planned hull items must be changed to other (due to accessibility or other reasons)
  - some planned hull items are not able to be completed within a given annual
  - planned thickness measurements surveys (HTM) are not convenient to be carried out at the time system proposes
  surveyor, in agreement with vessel, may de-select and/or swap the scope for current annual, and the system will ensure that scope is corrected accordingly in an annual survey later in the class period
• For owners being used to update their planned maintenance systems according to due dates on hull items, as listed in the status view, can in the new system update their PMS with the actual hull items being required for inspection on an annual basis from the list of remaining items in the status view

If any further questions related to the above, please contact DNV through DATE.