Design Standards

Design Standards

On the 3rd May 3017, IACS released a draft Rule Change Proposal 1 (RCP 1) to the Common Structural Rules (CSR for BC & OT), 01 January 2017 version.  INTERCARGO has reviewed the draft Rule Change Proposal and provided IACS with comments.

During MSC 98 it was agreed that the 6 Non-Conformities (NCs), which were raised during the Initial Audits of the Harmonised Common Structural Rules, can be considered rectified and thus re-confirms that the Common Structural Rules are in compliance with SOLAS Goal Based Standards requirements.

See the article on the Outcome of SDC 4 (4th session of the IMO Sub-Committee on Ship Design and Construction), 13-17 Feb 2017, at the link here.

During INTERCARGO's 35th Technical Committee meeting (London, October 2016), Peter Contraros delivered a comprehensive presentation on the IMO Goal Based Standards with an emphasis in the IMO Audit findings.

A copy of the presentation can be found on the TechComm page (member login required)

INTERCARGO performed a review of the second Rule Change Proposal (RCP 2) and accompanying Technical Background and  informed IACS, by letter,  of the comments and concerns.A copy of the letter can be found here (member login required)

In summary INTERCARGO is very concerned with the downgrading of welding requirements at critical locations with what appears to be no technical justification:

  • Hopper Sloping Plate to Inner Bottom Plate – Downgrade from full or partial penetration to partial penetration only.
  • Transverse Web Frame to Hopper Sloping Plate – Downgrade from partial penetration welding to fillet welding only.
  • Transverse Bulkhead (TB) Lower Stool Top Plate to TB Lower Stool Side Plate – Downgrade from full penetration welding  to partial penetration welding.

INTERCARGO expressed  concern that,  in addition to the decrease of strength/increase of stress that will be a result of the downgrades, the lack of full penetration welding will also affect the ability to fully assess the weld quality. Additionally, the lack of prescriptive requirements, within the Common Structural Rules (CSR), for enhanced inspections of the critical locations at new build will worsen the situation resulting in the welds at these locations not lasting the CSR design life.

INTERCARGO also expressed their disappointment that the Rule Change Proposal did not align the various Class Societies’ NDE requirements (i.e. number of checkpoints) rather than leaving it to the discretion of the individual Class Society, which we believe is not in the spirit of the Common Structural Rules or SOLAS