Fire Scenario Development for South African Hospitals
Hospital fires continue to present a serious threat to life safety, particularly in developing countries such as South Africa (SA), where outdated infrastructure, limited maintenance, and unreliable fire protection systems compromise effective fire safety management. Hospitals are uniquely vulnerable environments in which evacuation is complex, delayed, or, in many cases, impractical for the health of occupants. The day-to-day function of a hospital is complex, requiring the combined operation of many services, including surgical and medical services, kitchens, laundries, chemical laboratories, and janitorial services, to name a few. The result is an occupancy with a large variety of combustible and toxic materials, plentiful ignition sources, and complex evacuation mechanisms due to the vulnerable patients. The safety of hospital occupants, therefore, depends heavily on the integrity of compartmentation, the functionality of fire protection systems, and the preparedness of staff to effectively implement defend-in-place procedures. Despite these risks, limited research has examined how operational practices and system reliability influence tenability conditions in SA hospitals, where prescriptive fire-safety standards may not account for the complexity of hospitals and are often poorly enforced. This study investigated the development and spread of heat, smoke, and combustion products in a representative SA hospital ward using the Consolidated Fire and Smoke Transport (CFAST) two-zone model. The objective was to evaluate how typical SA operational and emergency procedures, and system functionality influence environmental conditions affecting vulnerable occupants. Following a performance-based design (PBD) methodology, three “representative” design fire scenarios were developed to represent credible fire hazards identified through stakeholder engagement and literature review: (1) a fire which blocks a major escape route, (2) a threatening fire which occurs in an unoccupied room, and (3) a fire which occurs in a patient sleeping room. Each scenario was simulated under varying procedural (compartmentation – closing doors and windows) and system (functional or non-functional detection and linked ceiling ventilation) conditions to provide a comparative understanding of their influence on tenability outcomes. The results showed that functional ceiling ventilation had the most significant impact on tenability conditions, particularly in patient rooms. Functional ceiling ventilation proved particularly effective in reducing smoke accumulation and limiting the spread of toxic gases, while non-functional systems led to extensive smoke spread and tenability loss across the ward. Compartmentation played a significant role in reducing the early spread of heat and smoke, but in some cases, door leakage resulted in delayed tenability exceedances in the patient rooms. Effective compartmentation, however, significantly worsened corridor conditions by concentrating heat and smoke within the corridor, demonstrating a clear trade-off between room and corridor protection, an essential consideration for the defend-in-place evacuation strategies adopted in hospitals. The combination of functional systems and effective compartmentation procedures proved critical to maintain tenable conditions in the patient rooms across all design scenarios. These findings underscore the importance of protection system testing and maintenance, as well as adequate staff training, in hospital occupancies. Furthermore, this study demonstrated the strengths and challenges associated with adopting a PBD framework to assess the state of fire safety in these buildings. While the PBD process can provide thorough fire safety assessments that account for specific contextual building challenges, it requires a high level of skill and regulatory compliance, making it less suitable for the SA context in its current state.
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