## 3 Results
### Ship Factors Influencing Evacuation
#### 3.1.1 Impact of Heeling and Trimming Angles  
It was identified that heeling angles (Figure 2) substantially impact both the duration and effectiveness of evacuations. As the angle of heel increases, both the Total Evacuation Time (TET) (Total Evacuation Time (TET): This metric measures the period from when evacuation orders are issued until the final individual reaches the assembly stations. TET is comprised by two main components: response time and movement time. Response time is the interval between the initial emergency alert and the commencement of occupants' movements towards safety, while movement time covers the journey occupants undertake from their initial location to the assembly points, including both walking and queuing durations [14; 15]) and Mean Completion Time (MCT) (Mean Completion Time (MCT): This metric represents the average time it takes for an individual to complete a defined task or reach a goal. In evacuation research, MCT refers to the average time required for individuals or groups involved in the evacuation to reach the assembly stations. MCT is calculated by dividing the total evacuation time of all participants by the number of individuals in the evacuation population. This measure is crucial for evaluating evacuation practices and identifying potential bottlenecks, thereby aiding in the establishment of optimal safety measures [16]), also increase, indicating a prolonged evacuation process and reduced efficiency. In a simulation study conducted by [PERSON] et al. [17], it was observed that as heeling increases, so does the time required for complete evacuation, due to the added difficulty in maintaining balance and maneuvering through a moving environment. That study quantifies this with specific examples: at a 10\({}^{\circ}\) heeling angle, evacuation times rose by 15.2%, while at 20\({}^{\circ}\), times increased by a substantial 42.5%. At the extreme angle of 30\({}^{\circ}\), evacuation times surged by 142.9%, indicating that higher rolling angles lead to progressively larger disruptions in passenger movement. Consequently, this study showcases that heeling has an exponential effect on evacuation time. This implies that as rolling angles climb, even small increases in tilt cause disproportionate rises in evacuation time, a critical insight for safety protocol development.  
Figure 2: Figure indicating the heeling angles of a ship. Source: [[https://www.fao.org/4/i0625e/i062](https://www.fao.org/4/i0625e/i062)]([https://www.fao.org/4/i0625e/i062](https://www.fao.org/4/i0625e/i062)) 5e02a.pdf, accessed on: 12 December 2024.  
Further support for these findings comes from another simulation study by [PERSON] et al. [18], using the maritime EXODUS tool. This tool, which integrates prescribed evacuation analysis methods with real trial data on passenger behavior under various trim and list conditions, demonstrated that factors such as trimming (Figure 3) at the bow significantly lengthened evacuation durations. More specifically, at 15\({}^{\circ}\) heel, the time for complete evacuation increases significantly, impacting overall clearance times due to slower movement through corridors and stairways. However, this later study found no significant difference between left and right heeling, as the ship's layout is symmetric. Moreover, bow trimming caused evacuation times to rise by as much as 46.4% in scenarios with a 20\({}^{\circ}\) tilt, since numerous passengers were concentrated near the bow and had to move towards the stern. This forward tilt makes ascending stairs particularly difficult, as it slows walking speed in forward-facing areas due to increased gravitational resistance. Similarly, stern trimming also slows evacuation but to a lesser extent than bow trimming, with a 20\({}^{\circ}\) stem trim increasing evacuation time by 29.3%.