Takt time optimisation is critical for improving production efficiency in railway manufacturing, particularly within car body shell production lines. Unlike automotive production, railway manufacturing involves larger and more specialised components, extended assembly cycles, and lower production volumes, making takt time management more complex and susceptible to bottlenecks. This study adopts a quantitative case study approach to investigate bottlenecks and capacity management strategies in a South African railway manufacturing facility. Data were collected through time–motion studies, production logs, and structured questionnaires administered to graduate trainees, quality engineers, production managers, process engineers, and operators. The analysis identified welding delays, material handling inefficiencies, and unbalanced workstation loads as key bottlenecks that disrupt operational flow and extend takt time beyond optimal thresholds. Further statistical examination revealed that workforce skill variability, equipment downtime, and supply chain inconsistencies also contribute significantly to inefficiencies in takt time. To mitigate these challenges, the study evaluated capacity management interventions including line balancing, predictive maintenance scheduling, and lean workflow redesign. The findings indicate that the adoption of these strategies can reduce takt time, thereby enhancing throughput and resource utilisation. The study provides practical insights for optimising production processes and supports evidence-based decision-making in railway manufacturing operations.