Unnecessary death of a tanker

The sheer enormity of the potential outcome of the tragedy of Banglar Shourav is overwhelming. Half the ship's complement could have been killed. Luckily, the explosion happened during lunch time, when most of the crew were inside their accommodations, so only a few remained in the danger zone.

Before going into further details on the Banglar Shourav incident, explosions and how they occur in tanker vessels should be addressed. Explosions are basically fires (an exothermic reaction of fuel, i.e. hydrocarbon with oxygen) taking place in a confined space. The reaction propagates so rapidly that a large amount of pressure accumulates, which eventually breaks the confinement, such as a container or cargo tank. This creates shockwaves, triggering successive layers of air surrounding the epicentre to rapidly expand. As a result of these shockwaves, steel structures are torn apart, heavy metal pieces are flung about like thin paper, and human bodies are shredded into unrecognisable heaps of flesh, bone, and blood.

Fire is always described using a triangular model, with each corner representing heat, fuel, and oxygen. A hydrocarbon compound is composed of the two elements carbon (C) and hydrogen (H). The simplest hydrocarbon is found in the form of methane (CH4), which has one atom of carbon and four atoms of hydrogen. As the molecule becomes longer and heavier, methane moves to a liquid state. In crude oil, the bulk of the hydrocarbon remains a liquid, although the lighter parts are vapourised and remain trapped in the ullage space of the cargo tank as gas.

Heavier, longer chains of liquid hydrocarbon are less susceptible to heat because their flash point, or the temperature at which they create enough vapour to ignite, is usually high. Heat causes the liquid fuel to ignite, since it vapourises and increases the temperature of the air-fuel mixture. After the initial ignition, a chain of exothermic reactions takes place, which release enough heat to ignite the remainder of the liquid fuel, and an explosion ensues.

Fires and explosions are usually controlled by any of the three following processes: (1) starvation: depriving fire of fuel, (2) smothering: depriving fire of a supply of oxygen, or (3) cooling: depriving fire of heat.

While extinguishing, cooling, and smothering are widespread practices, fire prevention is more important. That is why a small spill is mopped up quickly, flammable liquid is separated from a heat source, and other techniques are practiced in industries.

For any fire to occur, hydrocarbon vapour needs to be in an exact proportion to the air and this range is called "The Range of Flammability," which varies depending on the nature of the hydrocarbon. The upper limit of this range is called the Higher Explosive Limit, and the air to vapour ratio is 9:1. On the other hand, the lower limit of flammability, or the Lower Explosive Limit, is likewise defined as the ratio of air to vapour at 99:1. Most hydrocarbons will burn within these limits.

Cleaning the cargo tank is one of the most hazardous activities in which fires and explosions are high risks. While cleaning a tank, a lot of oil vapour is released as the high pressured jet of air comes into contact with the oil residues and sludge that stick to the walls of the cargo tank. Ignition is highly likely, as micro sparks are emitted at the area of impact, and the availability of air is difficult to cut off.

Due to this risk, operation manuals deal with tank cleaning in a most thorough manner. A thorough description of the process is included in the Tanker Operation Manual, as well as the pros and cons of various techniques and the nitty gritty of safety practices. Under the compulsory implementation of a ship's International Safety Management Code (ISM Code), this TANK CLEANING PROCEDURE is the first line of defence against fire and explosion disasters. It encompasses every aspect of this procedure-- the type of atmosphere the ship-staff must maintain, the do's and don'ts, checklists, work instructions, emergency preparedness and contingency plan, notices and notifications, etc.

It is astonishing to learn, via the investigation report,that three electric blowers, instead of water-powered blowers, were used for carrying out a gas-freeing operation onboard Banglar Shourav. On the deck of any tanker vessel, even the use of mobile phones is prohibited. Ordinary torch lights are prohibited, as well as shoes with nails, in case they produce sparks while rubbing the steel deck. Match boxes are searched and retained at the gangway. All electrical and electronic equipment used on deck are made INTRINSICALLY SAFE. This means any spark produced while using this equipment would be incapable of ignition.

An electric blower found on the deck of a tanker vessel is in direct violation of mandatory Tanker Safety Procedures. On Banglar Shourav, three electric blowers were used and were connected with ordinary cables and multi-plugs. This was simply suicidal.

It was revealed that the Second Officer was not aware of the safety procedures, and therefore unfit for the job. He even failed to report to the Master a small explosion prior to the one which killed three people. It was also said that the incompetent staff were hired unfairly, despite not meeting the required qualifications.

The responsibility of safety on board any ship, let alone a taker, is clearly defined through the implementation of ISM Code. The master of the vessel is given both the responsibility and authority to ensure the safety of staff, cargo, and ship, and he takes precedence over all other staff in discharging safety commands. Did the Master report the unacceptability of particular staff, or did he decline to accept them onboard on account of their incompetence? Did anyone assess the competency of the staff before delegating such a serious job as cleaning the tank? Did not anyone notice that open electric blowers were being used instead of water driven blowers? Who authorised their use? Was the level of hydrocarbon vapour measured in the tank? Was a checklist followed? Was there a permit to work? Did any senior staff supervise? This series of question is long; nonetheless, they need to be answered in order to prevent similar tragedies.

There is no question that the incompetence of the staff, as described in the investigation report, was the cause of this tragedy, but it is also clear evidence of a total failure of the Safety Management System, as well as everyone who was linked in the safety chain. Everyone onboard shares the responsibility of a disaster.

It is always easy to cite human error as the cause of disasters, but it is more difficult to identify and correct the underlying lacunae in the system. If this is not carried out, further explosions are probable, and they may not always occur during lunch time. Due to a few people's carelessness, three lives were lost, and a ten million dollar ship, which had generated significant revenue for the Bangladesh Shipping Corporation during its service,was destroyed.

Our grief is for the loss of such a prized tanker, and for the loss of three lives, including the young and promising Chief Officer, and the utter disrespect the ship's corpse received by way of looting and the stealing of its fixtures and interiors while it was waiting to be scrapped. By all means, Banglar Shourav deserved a more dignified departure.

Banglar Shourav was a valuable asset to this nation, and due to carelessness, it died an untimely death. Safety lessons can and should be easily learned, yet they continue to be learned the hard way. Until safety procedures and guidelines are followed, this sort of disaster will continue to plague industries for the years to come.