In this blog post, we’ll revisit the causes of the Titanic disaster and examine the impact that tragedy had on the development of maritime safety technology.
Do you know about the incident in which thousands of people, who had set out on a dreamlike voyage aboard the Titanic—the world’s most beautiful luxury liner—lost their lives in a single moment? This tragedy became even more famous thanks to the movie *Titanic*, which was inspired by the event. The Titanic, launched in 1912, was a super-luxury passenger liner built with the finest technology and materials of its time, and was known to people then as the “ship of dreams.” For Europe’s wealthy elite and adventurers, America was a land of new opportunities, and the Titanic was not merely a mode of transportation but also a symbol of status and wealth. The thousands of passengers aboard the Titanic expected a comfortable journey, enjoying top-notch service and facilities as they crossed the Atlantic, but that dream was shattered in an instant.
As depicted in the movie, only 710 of the 3,327 people on board the Titanic survived. The reason for such a high death toll was that the Titanic lacked sufficient lifeboats—only one-third of the passengers could escape in them—and the ship’s watertight bulkhead system, designed to prevent water from entering, was inadequate, causing the ship to sink too quickly. If the Titanic had had more lifeboats, or if it had held out a little longer instead of sinking, more people could have survived, and the beautiful love story of the protagonists depicted in this tragedy might have been preserved.
So why did the Titanic, despite being a luxurious passenger liner equipped with the most advanced technology of the time, meet such a tragic end? First, because regulations at the time were lax, allowing the Titanic to sail even though it had far too few lifeboats. Second, the actual flooding during the incident was far more severe than the watertight bulkhead system had been designed to handle. Since early 20th-century maritime safety regulations did not strictly mandate the number of lifeboats based on passenger capacity, the crew and passengers—who had blind faith in the ship’s safety—were also ill-prepared for the shortage of lifeboats.
However, the sinking of the Titanic served as a catalyst for significant changes in maritime safety standards. Laws have since been amended to require that passenger ships be equipped with a sufficient number of lifeboats commensurate with their passenger capacity in order to operate. Furthermore, the design of watertight bulkhead systems and drainage systems has been significantly strengthened. However, no matter how robustly a watertight bulkhead system is designed, it cannot completely eliminate the risk of sinking. This is because humans cannot predict nature. No matter how sturdy a ship is designed, no one can know what severe natural phenomena it might encounter.
Therefore, engineers have developed this into a distinct field of engineering, aiming to prepare for risks through quantitative predictions using the utmost effort possible. This risk prediction technique is called FSA (Formal Safety Assessment). FSA is a technology that quantitatively calculates the risk level of an event using probability. Let’s take the Titanic disaster as an example. First, let’s call the probability that the Titanic will strike an iceberg and sustain damage to part of the ship P1. Next, let’s call the probability that the watertight bulkhead system will fail to stop the incoming water once the ship is damaged P2.
Using this method, we can also determine the probability that the incoming water will damage the ship’s electrical, propulsion, and engine systems. However, not all these probabilities have the same impact. For example, while the probability of the ship being damaged by an iceberg is very low, the impact of such damage on the ship’s sinking is very significant.
In this way, FSA helps establish practical priorities for problem-solving by analyzing potential risk factors in advance. Let’s call the severity of each event S and assign a severity rating to each. For example, if we assign a severity rating of S1 to a scenario with a probability of P1, we can calculate the overall severity of the event. In FSA methodology, this severity is called “risk” and is expressed by the following formula:
Risk = Pn × Sn
(where n is the number of cases, n = 1, 2, 3…)
Using FSA, we can quantitatively calculate the various dangerous scenarios leading up to the Titanic’s collision with an iceberg, the resulting damage to the ship, and its subsequent sinking, which claimed countless lives. By sorting the risks obtained in this way by magnitude, we can prioritize and design which parts of the system to reinforce. For example, while the probability of the ship being damaged by an iceberg, as in the case of the Titanic, is low, and even if the probability of damage to the watertight bulkhead system is low, the risk is extremely high if damage does occur; therefore, the risk is ranked among the highest values. Consequently, we can conclude that the watertight bulkhead system must be reinforced as a precaution.
If the FSA method had been used in the design of the Titanic, the ship would have been built more robustly. If the watertight bulkhead system had been stronger and delayed the sinking of the ship, many more people would have survived. However, since the FSA method is fundamentally based on probability, 100% accurate predictions are impossible. This is because probability is, by its very nature, a measure of uncertainty—just as it is impossible to predict whether a coin will land on heads or tails when tossed. Consequently, safety engineers around the world are still developing methods to reduce the inherent margin of error associated with probability in risk calculations, in order to improve the accuracy of FSA.
