The Tragedy of the Titanic: Why Did a State-of-the-Art Cruise Ship Sink, and Are Current Safety Regulations Enough?

The tragedy of the Titanic was caused by a lack of lifeboats and weaknesses in the watertight bulkhead system, and modern safety engineers are trying to predict and prepare for these risks through FSA techniques.

 

Do you know the story of the Titanic, the most beautiful luxury cruise ship in the world, where thousands of people on a dream trip lost their lives in a split second? The movie Titanic, based on this event, made it even more famous. As the movie shows, of the 3,327 people on board the Titanic, only 710 survived. The reason for such a high number of victims was the ship’s lack of lifeboats, which allowed only one-third of the passengers to escape, and the ship’s weak watertight bulkhead system that prevented water from entering the ship itself, which caused the ship to sink so quickly. If there had been more lifeboats on the Titanic, or if the ship had held on a little longer instead of sinking, more people would have survived, and the beautiful love between the main characters would have been preserved.
So why did the Titanic, an ultra-luxury passenger liner with the most advanced technology of its time, collapse in such a futile manner? First, because the regulations of the time were lax, allowing the Titanic to operate with too few lifeboats, and second, because the flooding in the actual event was too severe for the watertight bulkhead system to have been designed for. But what about now? The law has been changed to require that the number of lifeboats must match the number of passengers on a passenger ship in order for it to function as a passenger vessel. But no matter how robust a watertight bulkhead system is designed, it can never completely eliminate the risk of sinking. That’s because humans can’t predict nature – no matter how robust a ship is designed, no one knows what strong natural forces it will encounter.
That’s why engineers have developed a branch of engineering that attempts to prepare for it by making quantitative predictions of risk to the best of human ability. This risk prediction technique is called a Formal Safety Assessment (FSA). FSA is a technique that quantitatively calculates the risk of an event using probabilities. Let’s take the Titanic as an example. The probability of the Titanic hitting an iceberg and damaging a part of the ship is P1. The probability of the water bulkhead system failing to keep water out when the ship is damaged and water comes in is P2. In the same way, we can determine the probability of the water coming in and damaging the ship’s electrical, power, and engine systems. However, not all of these probabilities have the same impact. For example, the probability of the ship hitting an iceberg and damaging the ship is very low, but the impact of the damage from the iceberg on the ship’s sinking is very high.
When a ship is damaged and water comes in, even if the probability of that water reaching the engines and other organs is the same, the engine that moves the ship and the device that simply purifies the water used in the toilet are of different importance. If the purification equipment floods, it doesn’t have an immediate impact on people’s safety, but if the engine floods, the safety of passengers is immediately jeopardized. It’s the same way that a broken air conditioner in a car doesn’t threaten the driver’s life, but a broken brake can lead to a major accident. So we call each event S and assign it a degree of risk. For example, if we assign S1 to the risk of an event with probability P1, we can calculate the risk of the total event. In the FSA technique, this risk is called “risk” and is expressed as follows

Risk = Pn x Sn
(where n is the number of cases, n=1,2,3…)

With FSA, we can quantitatively calculate the number of risky events that could have occurred before the Titanic hit an iceberg, damaged the ship, and sank, claiming countless lives. By sorting these risks in order of magnitude, we can prioritize which systems to design to be robust. For example, on a ship like the Titanic, the probability of hitting an iceberg and damaging the ship is low, but even though the probability of damaging the watertight bulkhead system is low, the risk of damaging it is very high, so the risk will have a higher value, and you can conclude that the watertight bulkhead system should be strengthened just in case.
If FSA had been used in the design of the Titanic, the ship would have been stronger, and many people would have survived if the watertight bulkhead system had been stronger, slowing the ship’s sinking. However, FSA is inherently a probabilistic technique, and it is impossible to make 100% accurate predictions. This is because probability is basically the number of uncertainties in a coin that makes it impossible to predict whether it will come up heads or tails when flipped. Therefore, safety engineers around the world are still developing ways to reduce the error that probability inevitably introduces into each risk calculation in order to improve the accuracy of FSA.