What type of ventilation should be employed to halt the horizontal spreading of fire in a long, narrow building?

Trench ventilation is specifically designed for situations where there's a need to stop the horizontal spread of fire, particularly in long, narrow buildings. This technique involves cutting a trench in the roof to allow smoke and hot gases to escape, which helps to create a barrier that can limit the movement of the fire across the building's length. By effectively removing the heat and smoke, trench ventilation helps to control the fire's behavior, potentially allowing for safer operations for firefighters and limiting damage to the structure.

In contrast, natural ventilation focuses on using the building's openings to facilitate airflow, which may not be as effective in containing fire spread in a linear structure. Vertical ventilation is done by opening the roof to let hot gases escape and is typically used to clear smoke but may not directly address lateral fire movement within long spaces. Cross ventilation aims to create a flow of air through the building but might not be adequate for halting fire spread in a focused manner. Trench ventilation strategically targets the specific challenge of managing fire spread in the defined context of a long and narrow building layout.