Firefighting at Sea – Towards a Safe Ship Concept
The most important of all international maritime safety conventions is the International Convention for the Safety of Life at Sea (SOLAS). The first version was adopted at a conference in London in 1914. The catalyst for this conference was the sinking of the Titanic on her first voyage in April 1912, which cost the lives of more than 1,500 passengers. This was the beginning of the journey that put in place a regulatory framework to protect those who work and travel by sea.
Whilst the sinking of the Titanic was not fire-related, the convention introduced new international requirements dealing with, among other things, the provision of fire-resistant bulkheads, fire prevention devices and firefighting appliances on passenger ships. The convention came into force in July 1915, some three years after the loss of the Titanic.
In 1948, the convention expanded to include the maintenance of essential services in emergencies, structural fire protection - including the introduction of alternative methods of subdivision by means of structural fire protection - and the enclosure of main stairways. It was at this time that an International Safety Equipment Certificate was introduced for cargo ships over 500 gross tons.
It wasn’t until the introduction of the 1960 SOLAS Convention that many safety measures applying only to passenger ships were extended to cargo ships, including those dealing with emergency power, lighting and fire protection. Regulations dealing with construction and fire protection were also revised. Following the 1960 SOLAS conference, an agreement was reached to implement a unified international code dealing with the carriage of dangerous goods. The Maritime Dangerous Goods Code came into force five years later.
The SOLAS convention continues to develop. Chapter IX: Management for the Safe Operation of Ships, a new chapter to the convention, was added in May 1994, and the International Code for Fire Safety Systems (FSS) was adopted in December 2000.
It is clear that progress is often slow and change usually follows a disaster. It would be fair to say that a more risk-based approach has been adopted on land. A building’s performance and the principles of fire compartmentation, protection and response are considered at the design stage, with fire modelling used to evaluate and inform design approaches.
This brings me back to the title of this article, “Firefighting at Sea – Towards a Safe Ship Concept.” What does this mean? Whilst this is a concept that should apply to all vessels, the focus of this article is cargo ships. Cargo carrying capacity is increasing, as is the size of the vessel. Combined with smaller crew sizes, there is no doubt that the potential for more shipping disasters exists. Therefore, the intent of this article is to consider some of the key elements of a Safe Ship Concept. This includes:
- Regulatory framework
- Ship design
- Fire protection
- Safe carriage of cargo
- Crew competence
Regulatory Framework
Relevant regulation is set out in Chapter II-2 of the International Convention, SOLAS (Part A, Regulation 2), which sets out the (1) fire safety objectives and (2) applicable functional requirements . It is clear from this regulation that the principles of prevention, detection, compartmentation and life safety are all included. And so the question arises, is it the regulatory framework that is lacking or does the problem lie elsewhere? The regulatory framework must continue to evolve and be ready for the risks of tomorrow.
Ship Design
Fire safety objectives shall be achieved by ensuring compliance with prescriptive requirements. Given the concern now being expressed by insurers and others regarding the alarming number of containership fires, it would appear that these fire safety objectives are not being met. Therefore, the problem, at least in part, may lie with ship design.
In any emergency situation, especially a fire or explosion, the ship must continue to function. The heart (engine room) and the mind (command bridge) of the vessel must be protected to ensure continuous safe operation for as long as is foreseeably possible. Whilst the engine room is fairly well-protected with automatic fire detection and protection measures, the challenge is maintaining essential air supplies to sustain propulsion and power to vital equipment. Dangerous goods, declared or not, should not be stored in proximity to these two areas as they pose the greatest risk to the ship’s safety. The guidance, on risk based stowage, produced by CINS in 2019, provides good advice on this topic .
A ship’s hold can be compared to a high-bay warehouse with the added disadvantage of cargo stuffed in separate compartments (containers). As such, the early stages of a fire may not be detected due to the lack of buoyant fire gases. Once established, the fire can spread forward and aft with little in the way of structural containment to retard the flow of heat, flame and smoke.
Moreover, as ships grow in size, so does the stowage space. More rows and higher tiers equal more combustibles. Movement on deck takes longer, increasing deployment time and the physical effort required to attack a growing fire. Any delay in controlling the developing fire will expose an increased fuel load below and above deck.
Fire Protection
Passive Fire Protection. Passive fire protection measures are integral structural components designed to contain the spread of fire, heat and smoke, providing more time for a fire response and safe evacuation of occupants. At sea, the crew will not evacuate the ship, except in the most serious of circumstances. They are also the only fire brigade available to attend to the fire. Consequently, passive measures must be designed in a way that slows the spread of fire, heat and smoke, allowing for a timely deployment of firefighting resources.
Passive fire protection can include, among other things, structural bulkheads or automatic curtains that drop when alarms sound or heat is detected (examples of which can be seen in any modern shopping centre). Assessing the risk at the design stage should inform what passive measures are appropriate. Solutions must be practical and effective as well as proportionate in cost.
Active Fire Protection. Active fire protection measures require an action to detect, alert, stop or contain a fire. This action can be either automatic or manual. A common misconception is that active measures, such as sprinklers, are designed to extinguish a fire. Whilst sprinklers can often extinguish a small fire, they are actually a mechanism to slow fire spread and give time for an emergency response to be deployed.
Although most spaces have some degree of fire detection or protection, the major gap in this provision is on deck. The absence of active fire protection increases the risk of a fire growing beyond its incipient stages before either smoke or flame is discovered. Larger fires ultimately require greater resource requirements to bring the fire under control. The earlier a fire is detected the better.
The accommodation block and the command bridge are particularly vulnerable to external fire attack. A measure often adopted for buildings is the installation of external water drenchers to create a water curtain, which flows down the outside of the structure. Windows and doors may need additional protection to direct water over the opening.
The absence of any detection or protection on deck all too often results in a fire developing beyond incipient stages before it is discovered. Installing sensors, such as infra-red cameras, and remote-operated water monitors - in combination with water curtain or drenchers on lashing bridges - could provide separation between stacks, retard spread and provide remote means for attacking the fire whilst crew resources are put in place.
Fire detection in ships holds relies on technology designed in 1918 for open cargo holds. However, cargo is now carried in many containers, which are stacked in a hold similar in size and volume to a large warehouse. Fire in its incipient stages may produce smoke that has to vent from a container into a space where the ambient temperature is still relatively low and the smoke plume less buoyant.
The smoke must be drawn into the smoke detection system before travelling a considerable distance to the actual smoke detector which is often located within the CO2 room. The issue here is the considerable lag time between fire initiation and detection, during which fire growth continues.
The principal method of attacking a fire within a ships hold is the release of specified quantities of CO2. Holds are not hermetically sealed, and CO2 requires prompt release and frequent top up, according to manufacturer’s instructions. CO2 has limited cooling effect and boundary cooling needs to be employed.
Whilst CO2 is an effective extinguishing medium, alternative means should be explored, such as high-pressure water mist which has high latent heat capacity and can displace oxygen. Research may be needed to ascertain the capability of this method of fire control and the possible advantages compared to sprinklers, drenchers, or flooding.
Safe Carriage of Cargo
The biggest risk to crew and ship safety is the carriage of mis-declared cargo. Some shippers have already implemented measures that may, in time, make the carriage of cargo safer. However, these initiatives must be industry wide.
As the culprits who put safety at risk melt into the night, the industry should look at the benefits of trusted trader schemes with those not participating, subject to greater scrutiny. Additionally, since technology already offers the ability to track individual containers, it may be time to explore methods for integrating temperature monitoring into tracking or other devices to assist the early detection of fire.
Crew Competence
Seafarers are facing ever increasing challenges, too many to discuss in this article. The prospect of new propulsion methods and the risks associated with lithium-ion batteries, electrical vehicles, and undeclared dangerous goods bring new challenges to their working lives. It is clear that the training syllabus needs to change to prepare them for future risk.
Conclusion
Although much is being done to tackle the problem of fires on board cargo ships, there is still much to do. The industry now appears to be of one voice demanding change. Whilst I have offered some insight and possibly some solutions, others will have a contribution to make. However, I have no doubt that a safe ship concept encompassing a holistic approach is central to any long-term solution building upon the standards needed to meet challenges in the shipping world of today and tomorrow.