RS releases technical requirements to NAABSA ships
RS says it has developed technical requirements for ships, which will be periodically grounded in operation - NAABSA (Not Always Afloat But Safely Aground Ships).
Development of some regions for the Far East and the Extreme North requires carrying out loading/unloading operations in the Arctic shallow waters areas with no sufficient receiving terminals. The ships built with hull structures specially strengthened are able to be loaded/unloaded when stranded in safe mode.
RS requirements contain the recommendations related to hull structures strengthening and additional protection. The requirements to design loads and hull girder and local strength are also specified.
During the testing application of the requirements, Ship Class certificate will be provided with special note regarding possibility of grounding for ship that hull structures meet the requirements.
Based on testing results, the requirements to NAABSA ships will be introduced into the RS Rules and additional class notations will be available to assign as follows:
NAABSA1 — partial or full ship hull baring is permitted on plane homogeneous sand-and-shingle or sand-and-mud sea beds with no motion in calm water as harbours or sheltered areas;
NAABSA2 — in addition to NAABSA1 notation specified, motion and ship bow impact contact with sea bed at defined wave parameters are permitted;
NAABSA3 — in addition to NAABSA2 notation, hull baring of moored ship is permitted at specified distance from seashore line in rolling condition and ship hull structures subject to impact loads when contact with sea bed.