ClassNK & NAPA tie-up to Improve Ship Design

ClassNK and leading global maritime software company NAPA have announced a new joint project to reduce the time and cost of designing vessels in accordance with the new IACS harmonised Common Structural Rules. The new project will enhance the data linkage between ClassNK’s PrimeShip-HULL(HCSR) design support software with NAPA’s 3D model based integrated design software NAPA Steel greatly improving the efficiency of the ship design process and reducing the cost of designing vessels in accordance with the new rules.

Adopted in 2013, the IACS harmonised CSR will be applied to all tankers over 150m and all bulk carriers over 90m contracted after 1 July 2015. The harmonised CSR brings new requirements for more comprehensive structural analysis at the design stage, including FEM analyses covering the entire range of cargo hold structures, as well as new formulae for buckling, fatigue, and residual strength criteria to enhance safety and reliability. However, these new requirements also greatly increase the overall time
needed for vessel design.

In order to help reduce the burden of the new rules on ship designers, ClassNK released PrimeShip-HULL (HCSR), a multi-functional vessel design support tool that makes it easy for yards and designers to carry out rule calculations and optimize their designs in accordance with the new rules. The software, which was the first of its kind to incorporate the requirements of the new harmonised CSR, has been highly praised for
its ability to reduce the man hours required for initial ship design work under the new rules, and is currently used by more than 100 shipyards and designers around the world.

According to ClassNK Executive Vice President Yasushi Nakamura, PrimeShip-HULL (HCSR) is the world’s first design support software to incorporate the requirements of the harmonised CSR. “With PrimeShip-HULL(HCSR) we have already succeeded in reducing the additional time needed for HCSR vessel design by roughly 50%, but our goal is to reduce the workload and in turn costs for ship designers and builders around the world. By improving the link to NAPA Steel and other design software we believe we can achieve even greater results.”

Today 95% of the world’s vessels are built by yards which use NAPA’s ship design software, including its integrated 3D model based design system NAPA Steel. NAPA Steel allows yards to greatly rationalize their ship design processes, reduce calculation time, and rapidly create high quality finite element models.

NAPA President Juha Heikinheimo says: “Many of the world’s leading shipyards already use NAPA Steel to improve their design processes, and we see this improved data linkage as offering even greater benefits to NAPA Steel users. Improved linkage between NAPA Steel and ClassNK’s PrimeShip-HULL (HCSR) will allow yards building CSR compliant vessels to even further streamline their design process, while also
eliminating the need for designers to input duplicate data into multiple programs.”

Contents and expected release dates for the improved data linkage features include: Prescriptive Rule Calculation Data Linkage for Oil Tanker Transverse Members The existing data linkage capabilities which allow longitudinal members of 3D structural data to be rapidly transferred between NAPA Steel and PrimeShip-HULL(HCSR), will be expanded to allow transfer of data from 3D structures, including transverse webs, bulkheads and other transverse members. The first function to be developed will allow the PrimeShip-HULL (HCSR) Rule Calculation software to process transverse member data for oil tanker cargo areas, increasing the accuracy of structural evaluation during the initial design phase and dramatically shortening design lead times.

Direct Strength Assessment Data Linkage
In addition to shape of finite element mesh and scantling information, PrimeShip-HULL (HCSR) Direct Strength Assessment data linkage features will be expanded to include compartment information, member type information and Opening information from FE models created with NAPA Steel.
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Prescriptive Rule Calculation Data Linkage for Bulk Carriers & Product Tankers Further improvements will be made to allow data for bulk carrier and product tanker cargo area transverse structures to be transferred between PrimeShip-HULL (HCSR) and NAPA steel.

Prescriptive Rule Calculation Data Linkage for Non-Cargo Areas
Further improvements will be made to allow data for fore and aft part and engine room part to be transferred between PrimeShip-HULL (HCSR) and NAPA steel. Direct Strength Calculation Whole Ship Batch Analysis

This improvement will allow whole ship FE models created in NAPA Steel and other design software to be automatically broken into hold models based on the requirements of H-CSR, allowing automatic analysis of all of the cargo holds together. Analyzing the cargo holds altogether rather than one by one will eliminate the need to input information and carry out individual analyses for each hold, greatly reducing the man
hours required for the overall analyses.