A master stream device that is permanently mounted on an engine and plumbed directly into the pump is a __________.

A master stream device that is permanently mounted on an engine and plumbed directly into the pump is known as a deck gun. This type of equipment is specifically designed for large-volume fire suppression and is typically mounted on the top or side of a fire apparatus. It allows firefighters to deliver a significant amount of water to a fire from a fixed position, enhancing the ability to combat large fires effectively.

Deck guns are advantageous in that they can be operated from within the fire apparatus, minimizing the need for manual handling of hoses in high-pressure situations. This setup is crucial for quickly establishing a substantial firefighting stream without requiring additional equipment or setup time that would come with other types of master stream devices.

In contrast, a monitor is a general term that refers to any fixed or portable device used to deliver a master stream, which may or may not be permanently mounted on an apparatus. A ladder pipe typically refers to a master stream device that is attached to a fire ladder, allowing operators to reach elevated areas. A portable master stream device is one that is not fixed or permanently mounted, providing versatility but requiring manual setup and operation.