Which technique is used for foam application that involves directing foam at an angle to the fire surface?

The bank-shot technique involves directing foam at an angle to the fire surface, allowing it to spread out over the fire more effectively. This method takes advantage of the surface tension and movement of the foam, helping it to create a barrier over the fuel, thus suppressing the fire more efficiently. By applying the foam at an angle, it is more likely to cover the fuel surface thoroughly and helps in preventing re-ignition.

The other techniques mentioned do not emphasize the angled application. The drop-down technique typically involves letting the foam fall directly onto the fire, the roll-on technique is focused on rolling the foam onto the surface with less attention to the angle of application, and layering technique deals with applying foam in layers rather than directing it at an angle. Understanding these various techniques enhances the effectiveness of fire suppression efforts during firefighting operations.