Classification society ClassNK released a new longitudinal strength assessments software “PrimeShip-HULL(Rules)/PartC15” as part of its prescriptive calculation suite “PrimeShip-HULL(Rules)”. For ensuring further safety and streamlining structural design of ships, ClassNK issued amendments for Chapter 15, Part C of its Rules for the Survey and Construction of Steel Ships relevant to the longitudinal strength in June 2017. The amendments included clearer standard for transverse members at the buckling strength assessments.