March 2020: Crane block design update on IHI and IHI-WMMP deck cranes

This safety update is issued to make available advice from the manufacturer about recommended reinforcement of the crane block. Classification societies may accept alternative crane block designs.

This safety update applies to any ship with an IHI or IHI-WMMP deck crane.


This safety update is for

  • stevedores in New Zealand ports
  • ships’ agents, charterers and ship operators
  • Classification Society surveyors
  • competent persons (as defined in Maritime Rules Part 49: Ships Lifting Appliances)
  • Maritime NZ Maritime Officers
  • port companies


IHI and IHI-WMMP deck crane 30 tonne cargo blocks

IHI Corporation has produced updated guidance that recommends modifications to IHI and IHI-WMMP 30 tonne deck cranes. IHI’s guidance is attached below.

The crane block design in IHI’s guidance is not the only acceptable design. Classification societies may also accept alternative crane block designs.

No independent evidence has been presented to support these views, and there may well be other factors involved in the failures. While Maritime New Zealand (MNZ) is providing a copy of IHI’s guidance to highlight safety issues with the cranes, MNZ is not in a position to endorse IHI’s views as regards the mode of failure.

IHI Corporation’s guidance on deck crane 30 tonne cargo block design:

IHI Cargo Block Guidance [PDF: 850kB, 12 pages]


What you should do

Ship operators should contact IHI Corporation to discuss reinforcement or replacement of your crane blocks. IHI can be contacted through their website

Original source content - This safety update replaces safety update 33: Crane Block Failures on IHI and IHI-WMMP Deck Cranes.


Contact us for more help

If you have any questions about this safety bulletin, please contact our Wellington office.


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