The Swedish Club informs about a controllable pitch propeller (CPP) failure caused heavy contact with lock gate. Namely, a vessel was waiting to proceed through a lock to another berth. The OOW had not checked the CPP as the vessel was alongside for twelve hours. He was also stressed to prepare everything for departure in a short time.
The incident
A vessel was berthed alongside a quay, awaiting to proceed through a lock to another berth. The pilot called on the radio and asked the Master if it was possible to leave in half an hour. The OOW completed pre-departure checks, the radar was tuned and the ECDIS set up for departure.
However, the OOW did not check the controllable pitch propeller (CPP) as the ship had only been alongside for twelve hours and the OOW believed everything was OK. He was also stressed to prepare everything to leave in such a short time. According to the company’s SMS, the CPP should always be tested before departure.
The Master came on the bridge along with the pilot. The OOW did a quick handover and then moved to the forward mooring station. The Master and pilot had a short pilot briefing and then the Master gave the order to let go all lines.
The vessel proceeded towards the lock and was in the final approach when the Master realised that the CPP was not responding correctly and the vessel was approaching the lock fast. The Master tried to regain control of the CPP system, but the pitch was stuck at around 40% ahead, leading the vessel to accelerate.
The Master panicked and was unsure what to do, so he shouted on the radio to the mooring parties to get the lines ashore and stop the vessel. The forward mooring party managed to get the forward spring secured to a bollard but no other lines were attached. The pilot ordered the tug that was standing by beside the vessel, to push the vessel towards the quay. This caused the vessel to make heavy contact with the quay, but unfortunately did not slow it down enough. The ship continued towards the lock at a speed of about three knots, the forward spring broke with a loud bang, and finally the vessel made heavy contact with the outer lock gate.
Shortly after the impact the Master pushed the emergency stop button for propulsion. After that the engine control room took control of the propulsion.
Probable cause
After the incident, the Chief Engineer and First Engineer inspected the CPP system to determine if something was wrong. Before any third party was able to investigate the CPP, the Chief Engineer cleared the system. This destroyed any evidence of what might have caused the incident.
The vessel was also boarded by port state and class inspectors. The vessel sustained damage to its bulbous bow, the tug minor damages and the lock gates sank. There were no injuries or pollution. However, there were costly repairs to both the lock and vessel.
It was also discovered that the company had four similar CPP near misses reported on sister vessels. The company had not made any changes to the PMS (Planned Maintenance System) or sent any special instructions to the vessels in the fleet.
Lessons learned
According to the Swedish Club, the following are key lessons in order to prevent similar incidents in the future:
- Make sure that the OOW understands why it is important to test all equipment according to the checklist, both for departure and arrival. This showcases the importance of conducting the checks required by the SMS;
- The Master did not save the vessel’s Voyage Data Recorder (VDR). This was done by a port state inspector two hours after the incident. The VDR must always be saved as soon as possible after an accident. It is important to have procedures that ensure that any evidence of what may have caused an accident is not removed or cleared in order to understand and learn why the accident took place;
- Always try to establish why an accident happened so it can be shared with the fleet. The near misses that had been reported to the company were never acted upon. Specifically, the Swedish Club said that ‘there is no point in having a near miss reporting system if nothing is then done about the reports’. Near misses and best practices should be shared within the fleet.
