Executive summary

What happened
In the early hours of 25 May 2023, the container ship CMA CGM Puccini was departing the port of
Melbourne under the conduct of a harbour pilot. As the ship continued downriver, main engine
power was increased and the rudder used to remain in the centre of the channel.
Just after 0444, the bridge team noticed that the rudder was not responding to the helm ordered,
with the ship turning wide in the channel as attempts were made to verify and restore steering. A
few minutes later, the ship closed on the western edge of the channel and contacted navigation
beacon 32. The ship was then slowed and returned towards the middle of the channel. By 0454, it
was stabilised in the channel with tug assistance and then conducted to nearby Webb Dock. The
ship suffered minor hull paint damage and beacon 32 was significantly damaged.

Photo: Graeme Waller

What the ATSB found
The investigation found that one of the steering hydraulic pump bypass valves had been left open
following earlier testing. In this condition, the steering operated sufficiently well with minimal load
on the rudder to pass pre-departure visual inspection. However, when the hydrodynamic loads on
the rudder increased, with increasing ship’s speed and rudder movements, the open bypass valve
allowed leakage of hydraulic oil and system pressure around the pump leading to erratic response
of the rudder.

The investigation also found that several officers on board were not as proficient with steering
gear operation and change of control modes as was required by regulations. Further, steering
terminology used on board and within the CMA CGM fleet was not clearly and explicitly defined –
official fleet terminology was ‘steering gear failure’ and did not recognise common industry terms
such as ‘emergency’ and ‘local steering’.

Consequently, unnecessary procedures, which included reconfiguration of steering hydraulics,
were followed when using and demonstrating steering from the steering compartment. Following
one such demonstration, one of the bypass valves was not closed.

Further, the possible confusion between common-use and official CMA CGM terminology existed
fleetwide and was not clarified in the procedures or other guidance. This increased the risk of a
similar unnecessary, and incorrect, configuration of the steering machinery occurring elsewhere in
the fleet.

What has been done as a result
In addition to other investigations, CMA CGM commissioned the steering gear manufacturer to
conduct independent tests of the steering gear and its operation. In late 2023, CMA CGM notified
all ships in its fleet of the incident in the regular fleet circular. Several months later, all ships and
the company’s designated persons ashore were reminded of this incident and to follow the
steering gear failure procedure.

In order to fully address the safety issue, CMA CGM has advised the ATSB that its fleetwide
‘steering gear failure’ procedure has been amended and titled as the ‘emergency steering
procedure’. The amended draft procedure defines emergency steering and clearly outlines the
change of steering control from the navigation bridge to the steering gear room. The draft
procedure is to be assessed by the company’s technical committee before it is finalised for an
expected fleetwide implementation in March 2025. The ATSB will monitor the safety issue and
reassess its status once it is implemented.

Ports Victoria has updated the harbour master’s directions for Melbourne to strengthen towage
requirements in the Yarra River and include advice for the crews of ships that experience a main
engine or steering failure while transiting port waters.

Safety message
All seafarers are reminded that ‘any loss of steering may imperil the safety of the ship and life at
sea’. Steering is a vital ship system and any source of possible confused or incorrect operation,
especially in an emergency, is a risk which should be minimised. Unclear or ambiguous operating
instructions and terminology should be corrected as soon as they are identified.

Seafarers and shore management are reminded of the importance of ensuring shipboard
personnel understand and are competent in how the ship’s steering machinery and control
systems operate. Ship’s officers in particular should be aware of the correct procedures:
• for changeover of steering control from the navigation bridge to the steering gear compartment
• to follow in the event of steering gear failure, especially failure of remote steering from the
navigation bridge and during ship manoeuvring, such as when entering or departing ports.

Source: ATSB