A vessel had reported steering failure at sea and was boarded by port state control upon arrival. The steering gear was inspected without any findings and the vessel was allowed to proceed. The class was not informed. Whilst sailing half ahead on a river, the rudder suddenly blocked in a position nearly hard to starboard. The vessel touched the riverbank and stopped. All parts of the steering gear (machinery and bridge) were inspected by the crew and found in order. The captain and the pilot decided to continue the voyage, however, the problem reoccurred and the vessel ran aground again!
The class was now requested by the port state control officer. This time one of the hydraulic cylinders of the steering gear (linked cylinder type) was found warmer than the others. The piston was disconnected and the vessel berthed in the next port. The vessel was equipped with two rudders.
After opening up the dismounted hydraulic ram, the piston thread and the cylinder cover thread were found damaged and on the cylinder itself there was a deep scratch. The pin connecting the rudder stock to the connecting rod between the two rudder stocks, was found scored and the pin housing damaged. Fortunately the two groundings did not lead to a collision or any hull damage.
Actual steering gear of mentioned vessel.
The damaged hydraulic ram was obviously not original from new-building as it differed from the three others in terms of colour, design and manufacturing. The manufacturer of the steering gear ensured that they were not involved in the change of the ram, nor had they deliver any spare parts.
The following are considered as lessons to be learned regarding the mentioned case:
- It is crucial to establish the cause of steering gear malfunction before continuing a voyage.
- The Class should be involved as soon as possible in case of damage or malfunctioning of the steering gear.
- Manufacturers recommended spare parts should be used at all times.
Source: DNV
Officer of the Watch 
Leave a Comment