What effect does aiming slightly above horizontal have on the thermal column during a fire?

Aiming slightly above horizontal during firefighting operations is effective because it improves the cooling of the thermal column. When firefighters direct water at an angle that is just above horizontal, they allow the water to travel through the hotter gases rising from the fire. This practice helps to penetrate the thermal column more effectively, facilitating the absorption of heat energy from the smoke and gases.

As the water interacts with the superheated air and smoke, it absorbs heat, leading to a more significant cooling effect in the fire atmosphere. This also helps to reduce the risk of heat-related injuries for firefighters and can disrupt the thermal layering of smoke and gases, promoting better visibility and safer conditions for both firefighters and civilians.

In contrast, approaching the thermal column from a more horizontal position might not provide the same level of penetration, potentially leading to less effective cooling and prolonging the duration of the fire and its hazardous effects.