The use of remote inspection techniques (RIT) is increasing. Today, drones, climbers, or robot arms, can be used as an alternative to close-up surveys in both the DNV GL rules and IACS Unified Requirements. RIT may significantly reduce the survey time and costs, while improving the safety of surveyors and the owner’s personnel. From 1 January 2019, DNV GL has approved the use of service suppliers for RIT. This technical news explains how RIT can be used and how suppliers can achieve DNV GL approval.
Relevant for ship owners/managers, yards, suppliers and flag states.
Improved efficiency and reduced risks when performing hull surveys
A close-up survey normally means the structure is within the reach of the surveyor’s hand. With RIT, the surveyor can avoid the use of costly rafting, cherry pickers or staging, while still obtaining the information required to credit a close-up survey of a tank or hold. The attending DNV GL surveyor will witness the survey and watch the details of the close-up inspection through a live video stream. The quality of the data obtained during RIT-assisted surveys must be equivalent to that of a traditional survey. The data is later compiled into a final report.
Hence, there are several advantages to using RIT compared to visually checking the condition of remote structural components, including reduced time and costs needed for preparation before the survey and improved safety for the surveyor and owner’s personnel. RIT can also eliminate the risk of damaging coatings, while reducing the time and costs needed for set-up. The quality of the data obtained during RIT-assisted surveys must be equivalent to that of a traditional survey.
Approved service suppliers
From 1 January 2019, DNV GL approves service suppliers to provide close-up surveys using RIT – e.g. drones, climbers or remotely operated vehicles (ROVs) – for ships and mobile offshore units. The service suppliers must be able to successfully carry out a close-up survey according to the requirements given by DNV GL. Examples of the requirements include relevant training and qualifications of the drone operators, adequate resolution of the live streaming and proper illumination equipment.
Enhanced Survey Program (ESP) ships
As the ESP Code is not clear on the applicability of RIT, acceptance from flag authorities is necessary before RIT is used for class surveys on ESP ships (oil tankers and bulk carriers).
Requirements for certification
Programme-specific requirements have been developed based on IACS UR Z17 and included in Class Programme 0484, Appendix A 16 “Firms engaged in surveys using remote inspection techniques (RIT) as an alternative means for close-up survey of the structure of ships and mobile offshore units”. The new programme was released in February 2019. Please note that ROVs used for in-water bottom surveys are covered by a separate AoSS programme, CP 0484 A3.
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