Managing watertight doors

The frequency of major shipping losses has decreased by some 45 per cent over the last decade, and it is evident that improved safety barriers for controlling flooding have had a strong impact on risk mitigation and ship safety. Foundering – by sinking or submerging – is still the main cause of losses, accounting for half of all losses over the 2005 to 2016 period. Grounding is the second most frequent cause (20%), followed by fire (10%) and collision (7.3%).

In the most common accident scenarios, including foundering, grounding and collision, controlling the ship’s internal watertight integrity and, in particular, the watertight doors, can make a significant difference when it comes to reducing loss of life and assets. An open watertight door in a flooding scenario is a failure that may rapidly lead to capsizing or foundering without a chance of recovery, depending on the design of the given vessel.

Numerous risk factors

IMO recently also revised their guidance for watertight doors on passenger ships during their 98th session in July 2017. MSC 98 approved MSC.1/Circ.1564 on “Revised guidance for watertight doors on passenger ships which may be opened during navigation”, where one of the amendments removed a provision in regulation II-1/22 that had permitted certain watertight doors to remain open during navigation if so authorized by the administration.

Watertight doors must be used safely and properly to avoid endangering passengers and crew who are passing through the doors or operating them. However, casualty statistics indicate that this is not always the case. Root cause investigations after incidents involving power-operated watertight doors have revealed that it has been common practice on board ships not to open watertight doors fully before passing through. Door safety systems have also been found not to be in full working order during inspections, and some doors were not properly maintained or tested. Most accidents involving people occur when the doors are in bridge-controlled “doors closed” mode.

“Managing watertight doors as a safety barrier sounds like an easy, everyday task. However, it is indeed a highly complex operation involving technical systems, people and processes,” Trond Arne Schistad, Head of Statutory at DNV GL, explains.

A watertight door comprises several technical systems (structural, electrical, hydraulic, control) with many possible failure modes, and the doors are constantly subject to wear and tear. In addition, efficient barrier management depends on procedures describing correct operation during voyages and in emergency situations as well as correct and efficient maintenance. Finally, the human element needs to be addressed as well: crew and officers, their awareness of the risks involved and their knowledge and motivation to operate the system correctly during normal operation and in cases of an emergency.

In support of their customers’ efforts to eliminate safety risks related to watertight doors, experts at DNV GL and Gard, a leading Norway-based marine insurance company, have compiled a package of training materials to raise awareness of the correct use of power-operated watertight doors. “We have produced a video and a presentation that identify the key risks and technical and operational issues involved in using power-operated watertight doors, and provide some practical steps the maritime industry can take to address them,” Schistad summarizes the main content of the training material.

The key: being prepared

The material provides shipping customers with specific recommendations relevant to daily operation. These include tips on what a crew should be aware of, outline the actions the ship and shore-side management should take, and consider contributions from other industry stakeholders, such as manufacturers, class societies and flag administrations, to the reduction of risks related to the operation of watertight doors.

“A key element of the campaign is to develop a proactive doorclosing culture. This means being prepared for possible external events such as a collision or grounding or bad weather,” Jarle Fosen, Loss Prevention Executive at Gard, describes the ambitions of the project team. “We want to increase the confidence of the crew in watertight doors as a barrier in case of flooding, and create a better understanding of how watertight doors are designed and how they should be operated and maintained,” he explains.

Fosen continues: “We also found that it is essential to create awareness of the occupational risk of incorrect use of watertight doors, and to reflect on the potential conflicts this may create.” The project team has also been working with the industry on assessing work orders in planned maintenance systems related to watertight doors. An example of a work order and case study information are part of the awareness campaign package.

Excellent training material

The training material has been sent out to customers and tested successfully, as Captain Zissis Koskinas, Fleet Captain of Celebrity Cruises, reports: “This is excellent training material on this extremely important subject and therefore Celebrity Cruises has instructed our crews to use that material for training, although we already had material of our own. This initiative is essential and much needed for the ships’ watertight integrity and safety as well as for the safety of the crew operating those doors in order to prevent fatalities.”

After all, incorrect operation of watertight doors could put the safety of a vessel’s crew and passengers at risk, threaten the environment, and cause lasting damage to a company’s reputation. Schistad and Fosen recommend using the watertight doors awareness material in safety training as well as during safety meetings and officer conferences. Customers can contact DNV GL and Gard directly for further support.