NB: The below is a brief plain English summary of key points in the report. The Commission's report speaks for itself -- you can download the full document here: www.taic.org.nz/inquiry/mo-2023-203.
Briefly:
Deferred maintenance is a risk in itself. It’s virtually certain the container ship Shiling was unseaworthy when in NZ, despite holding valid certificates. New TAIC recommendations:
Ensure ship owners’ responsibility for risk
Change NZ law to ban substandard ships from NZ
Strengthen NZ’s salvage and rescue capability.
What happened
On 15 April 2023, the Shiling was turning into the Wellington Harbour entrance channel when the main engine stopped. The crew used both the ship’s anchors to stop the ship from grounding and it was subsequently towed by harbour tugs back to its berth to be repaired.
After repairs, the ship departed Wellington again on 12 May 2023 and was sheltering from adverse weather off the New Zealand coast. The bilge tanks were full and when the Shiling entered the Tasman Sea and began to roll, bilge water entered the lube oil tanks, resulting in the main engine stopping.
A tow-capable vessel sailed from New Plymouth to tow the Shiling to sheltered waters and eventually back to Wellington for repairs. Maritime NZ detained the Shiling for repairs and survey until July, when it departed for Singapore.
Why it happened
Blackout in Wellington Harbour - April 2023
Exhaust gases from a cracked cylinder liner in one of the generators entered the centralised system that supplied cooling water to all generators and the main engine. The cooling water temperature increased, tripping out the running generators, which caused the main engine to stop.
Although the ship held valid statutory and classification society certificates, the generators and several other safety-critical systems were in a deteriorated condition.
Breakdown in off NZ Coast - May 2023
Age had deteriorated rubber diaphragms intended to prevent water entering the lube oil tank. Very likely the diaphragms had not been inspected for many years.
This was despite insurance clubs and engine manufacturers issuing several bulletins warning of the critical importance of maintaining the diaphragms in good condition.
What we can learn
Ship owners carry the risk responsibility: The creators of risks are best placed to manage them. A ship owner who offers a ship for service must remain responsible for its safe operation, regardless of any other entities involved in operating, inspecting and auditing the ship and its systems.
Deferred maintenance = more risk: Deferred ship maintenance, especially of critical equipment and systems, will significantly increase the risk of accidents and incidents.
Safety-critical equipment problem? Fix it: Fully investigate failures involving critical equipment and systems, establish causes and resolve them before putting the systems back in service.
Safety issues and recommendations
The Commission’s report identifies seven safety issues and made four recommendations:
Risk responsibility – ship owners own the risk: several safety issues relate to international and domestic systems for regulating international ships and the ability of ship owners to devolve their responsibilities for the safe operation of their ships to third parties without regulatory consequences. TAIC has made recommendations to Maritime New Zealand to address these matters through the International Maritime Organization.
Ban substandard ships from NZ: Poorly maintained and/or managed vessels trading to New Zealand. TAIC recommends the Ministry of Transport consider legislating to give Maritime New Zealand the authority to ban certain ships from New Zealand.
Tow salvage capability: One safety issue relates to NZ tow salvage capability. TAIC recommends work continues to develop and implement a comprehensive maritime incident-response strategy that will strengthen salvage and rescue capability.
No repeat accidents – ever!
The principal purpose of the Transport Accident Investigation Commission is to determine the circumstances and causes of aviation, marine, and rail accidents and incidents with a view to avoiding similar occurrences in the future, rather than to ascribe blame to any person. TAIC opens an inquiry when it believes the reported circumstances of an accident or incident have - or are likely to have - significant implications for transport safety, or when the inquiry may allow the Commission to make findings or recommendations to improve transport safety.