People should not be allowed to remain under ferries’ mobile decks when these are being operated. The Nautical Institute describes an accident with such a deck in a new Mars Report. In this case, the mobile deck crushed a car with a trailer.
The Nautical Institute gathers reports of maritime accidents and near-misses. It then publishes these so-called Mars (Mariners’ Alerting and Reporting Scheme) Reports (anonymously) to prevent other accidents from happening. This is one of these reports.
A ferry was in port loading vehicles and passengers. The ferry was equipped with mobile decks that could be raised or lowered to load cars above the main deck. At the time, the automation for operating the mobile car decks was not functional so these decks had to be raised and lowered by manually operating the levers in proper sequence.
The crew member performing the task on this day had not done so for some time and the written instructions were not in the working language of the crew. The crew member pulled in the locking wedges for the platform too early, an “out of sequence” manoeuvre. This resulted in the platform falling freely for a short distance, putting high stress on the lifting cables and mechanism.
One of the sheaves of the lifting cables was torn loose by the increased stress. The spacer plates that were supposed to hold the two steel plates of the line sheave together broke under the load. Now, there was nothing to hold the cables in place and one side of the mobile deck fell to the main deck. A car with a trailer was crushed and two people suffered minor injuries.
Also read: Crushing fatality while moving pontoon tweendeck
Investigation findings
The investigation showed that there are no requirements for independent inspections of platforms for suspended (mobile) decks. However, requirements do apply to ramps that are defined as “lifting devices”. Mobile decks have a similar technical design to lifting ramps and the risks associated with construction and use are similar.
The disparate regulatory requirements for mobile decks versus lifting ramps do appear to be justified from a safety perspective. Similarly, there was no requirement for protection against wire breakage for suspended decks, whereas there is such a requirement for ramps.
The investigation also found that there were no technical measures to prevent the locking wedges from being pulled in before the platform had been raised. Finally, there was nothing to prevent people from being under the mobile decks during operation. This aggravated the consequences of the accident.
Also read: Tidy up or trip: Keep your deck free of clutter
Advice from The Nautical Institute
- There is no substitute for good training and complete familiarisation with the equipment being used. In this case, the crew member’s training in the operation of the mobile deck was less than adequate.
- Allowing people to remain under the mobile decks when the decks were being operated is a sign that better risk assessments are in order on this vessel and possibly others of similar design.
Also read: Crew member nearly crushed while loading ferry
Mars Reports
This accident was covered in the Mars Reports, originally published as Mars 202517. A selection of the Mars Reports are also published in the SWZ|Maritime magazine. The Nautical Institute compiles these reports to help prevent maritime accidents. That is why they are also published (in full) on SWZ|Maritime’s website.
More reports are needed to keep the scheme interesting and informative. All reports are read only by the Mars coordinator and are treated in the strictest confidence. To submit a report, please use the Mars report form.
Picture by The Nautical Institute.
