Who is the most dangerous type of ship? The question seems simple, yet the answer requires us to weigh probabilities and consequences in real conditions.
First of all, let’s say that all ships are potentially dangerous. There is no ship on which we can rest easy. Nevertheless, there are some types of ships that for various reasons are more dangerous than some others.
If we take into account all the parameters such as marine pollution, the flammability and toxicity of the cargo, the pressure of inspections, the complexity of operations, stability, but also the human factor, the most dangerous type of merchant ship is not a crude oil tanker, as one might perhaps expect.
The greatest operational risk today is identified in chemical tankers, and especially in parcel chemical tankers that carry multiple cargoes of different chemical composition simultaneously.
The reason is that here many factors of high danger and risk are combined. The cargo is not just flammable, but can simultaneously be toxic, corrosive, reactive with water, with air, with other chemicals or even with the tank material.
The handling of this cargo requires absolute precision and special treatment: temperatures, pressures, flash point, compatibility matrix. In most chemical tankers, there is no one standardized procedure that is simply repeated.
There, every voyage is different. Every cargo has its own characteristics, its own methodology for loading, heating, unloading and, mainly, its own cleaning procedure. A mistake is not forgiven, because it can lead either to an explosion, or a toxic leak, or an uncontrolled chemical reaction, thermal explosion, or gas formation.
On the other hand, the pressure of inspections is suffocating. OCIMF, CDI, SIRE 2.0, chemical producers, terminals, PSC, company audits, every arrival of the ship at the port is accompanied by a high workload, different documentation, different requirements. The continuous loading and unloading of many different cargoes also affects stability, where the management of free surfaces, bending moments and shearing forces is much more critical than in a crude carrier which may carry 1 or 2 different batches.
And to avoid misinterpretation. This type of problem is not encountered only by a chemical tanker but also by a crude oil tanker. However, we are examining the frequency and to what degree this happens.
At the level of environmental risk now, as is logical, crude oil tankers can potentially cause a much greater ecological disaster, due to the volume and nature of the cargo. If a mistake is made there, we are talking about an environmental crime with consequences that will exist for many decades.
But the probability of it happening is smaller compared to a chemical tanker, because crude tankers have much more standardized procedures and a smaller margin for human error. In chemical tankers, the complexity of the cargoes and the /unloadings increases the probability of something happening. And the combination of “high consequence risk + high probability of error” is what ultimately determines the greatest overall risk.
Most dangerous type of ship does not mean more accidents
If we look at it coldly from an operational perspective, chemical tankers are the most dangerous type of merchant ship.
If we look at it from the perspective of the consequences for the sea and ecosystems, then a disaster involving a VLCC crude oil tanker can cause incalculable damage.
So the answer depends on how we define risk: as probability or as magnitude of disaster. The real risk, however, appears where these two factors meet: Human error and the hazardous nature of the cargo.
The truth, however, is that in the era we are going through, we see very few accidents happening to tankers compared to, for example, container ships, for which we read almost daily about accidents, loss of human life, and pollution of the marine environment.
A ship being more dangerous than another does not necessarily mean that more accidents will happen to the less dangerous type of ship. This, furthermore, has to do with other factors such as the inspections that generally pressure the system, the crew’s training, the policies of each company, the age of the ship, and the maintenance it has undergone.
The major issue is to find the golden mean between paperwork and traditional seamanship so that accidents are reduced to a minimum. To make ships safer and more humane.
