Ship surveys for Russian Maritime Ship Register
“Vodolaznye raboty” LLC has successfully passed accreditation and now provides ship survey services for the Russian Maritime Register of Shipping (RMRS).
An underwater survey of ships is carried out to assign, confirm or change the class of the register according to the ships’ purpose.
To conduct underwater surveys of ships, as well as the underwater part of offshore structures with a diver, we use modern diving equipment and necessary control and measuring devices, a technically equipped diving station, underwater photo / video shooting is used to document the underwater inspection of the ship's hull or marine objects.
A diving station inspects the underwater part of the ship’s hull, propeller-steering complex (RCS), assesses the condition of the protective coating, the strength of the hull and the wear of its elements (welds, rivets, etc.). Divers also test the fatigue strength of hull structures. Each of the considered parameters is assigned with a corresponding rating of the register rating system.
To conduct a prompt ship inspection it is required to make preliminary preparations:
- The paper of the ship subject to inspection should be accessible;
- The transparency of water in the water zone should provide a good visibility of inspected objects;
- The depth under the keel should be sufficient for a thorough inspection of all sections of the underwater hull, steering gear, propeller shafts, propulsors and bottom-outboard fittings and systems of electronic navigation equipment;
- In places with insufficient lighting additional light sources should be used, which can provide the conditions required for a thorough inspection of a ship and a good quality image on the monitor;
- All objects should be in working condition, excluding emergency and repair cases;
- All safety measures should be observed;
- Prior to the start of the inspection the owner of a ship should provide data on all operational defects, damage and wear over the past 5 years, show ship records and log books.
- . The inspection is carried out in accordance with a specially developed program of underwater inspection framed by rules of the Russian Maritime Register of Shipping and approved by a Sea Register representative;
- To participate in the survey, a ship owner appoints a competent commission consisting of ship administration representatives and ship owner;
- The Inspector of the Register carries out the survey of the underwater part of the vessel according to the image transmitted to the monitor screen by the television installation. In this case, good visibility of the image on the monitor screen should be ensured.
Survey can be carried out at anchor or at sea, where the water is calm and clear. When conducting an inspection at sea, it is necessary to use a diving boat with technical equipment of the survey, and inspection can also be carried out from the berth, from the side of the inspected vessel or from another boat.
During the assessment of the technical condition of a monitored object, wear, damage or malfunction can be detected. In this case, the extent of their adverse impact on the safe operation of the vessel is determined: a) the state of the monitoring object is declared exploitable; b) the discrepancy of the technical condition of the object according to the requirements of the Register is confirmed, and the facility (ship or offshore structure) is declared unsuitable for operation. RMRS classification documents are issued only after the elimination of detected defects. Any damage and violation of the integrity of coatings, intensive wear of particular sections of the structures under investigation, which the inspector recognizes as dangerous for further operation, are subject to urgent repair.
Assessment of the condition of hull structures is carried out through visual inspection, measuring the thickness of various parts of the structure, organoleptic examination, as well as tests for impermeability. Inspection of the skin plating, kingston valves, etc. is carried out the inside and outside.
The inspector records the results of the survey in the reporting documents of RMRS.
Inspection of the underwater parts of a vessel
The underwater parts of a vessel are subject to inspection in order to confirm their compliance with the requirements of RMRS.
The underwater part of the hull, underwater elements of steering gears, propulsors and shaft lines, outboard openings, etc. are examined. Underwater survey of the ship's hull should be carried out in the dock.
During the 5-year period of RMRS class validity, at least 2 surveys of the underwater part of the vessel must be carried out. The time interval between the 2 surveys of the underwater part of the vessel should not exceed 36 months.
Prior to the start of the survey, it is necessary to prepare the inspected area: the underwater part of the body must be cleaned of fouling in order to make all possible cracks, chips and corrosion visible. All detected defects that pose a threat to operating availability should be eliminated; all critical areas which are subject to replacement, should be replaced.
Frequency of surveys
The initial survey of an operating vessel is carried out in order to assign it a class in accordance with the requirements of the RMRS classification. Also, this type of survey makes it possible to reassign a class in case of its previous cancellation.
An annual survey is carried out to survey and confirm the class of RMRS; also correct operation of various mechanisms and installations is checked.
During annual surveys, an external inspection of the monitored object is usually carried out.
An intermediate survey, is usually carried out between the 2nd and 3rd annual survey of a ship or offshore structure. During intermediate surveys, additional objects and structures that were not presented for inspection during the previous annual survey shall be inspected.
A regular survey is carried out in order to renew the class and determine that the technical condition of the examined object meets the requirements of the RMRS. The regular survey necessarily includes an examination of the underwater part of the vessel. The regular survey is carried out within a time period of not more than 5 years. The scope of the survey is specified by the commission inspector.
To datethe company “Vodolaznye Raboty” LLC has performed about 15 diving surveys under RMRS and inspected about 50,000 thousand m² of underwater ship structures.