Which type of fire hose should never be used as an attack hose?

The correct choice is large diameter hose. Large diameter hoses are primarily designed for water supply and are used for drafting, supply, or moving large quantities of water from a hydrant to a pump. These hoses typically have larger diameters, which means they are not intended for the high-pressure delivery of water to fight fires directly.

Attack hoses, on the other hand, are specifically designed for firefighting applications, featuring a smaller diameter to facilitate higher pressures needed to effectively combat fires. Soft sleeve hoses are also not structured for attack, but they serve a different purpose, such as connecting a water source to a pump in a more flexible manner. Non-collapsible hoses are built to maintain their shape under pressure, but they too do not meet the tactical requirements of an attack hose. The use of a large diameter hose in an attack scenario could result in inefficient firefighting and potentially hinder the fire suppression efforts.