What should be done when changing from an offensive to defensive mode regarding hand-lines?

When transitioning from an offensive to a defensive mode, continuing to flow water on exposures until master streams can be placed is crucial for several reasons. In defensive operations, the primary focus is on protecting lives and property from further risk, particularly when the situation escalates beyond control. By keeping water on exposures, firefighters can prevent the fire from spreading to adjacent structures or areas, which could exacerbate the situation and potentially cause additional damage or injuries.

This approach also provides a buffer during the transition phase, allowing crews to maintain some level of suppression while preparing to deploy more powerful master streams which are better suited for a defensive posture. Maintaining water flow during this critical time helps to manage the fire's intensity and create safer and more manageable conditions for both firefighters and those affected by the incident.

Additionally, while switching off hand-lines entirely or immediately relying on aerial apparatus may seem like viable options, they could leave structures vulnerable to fire spread, potentially allowing the situation to worsen while firefighters transition their strategy. Increasing flow rates without sufficient tactical planning can also lead to unintended consequences, including equipment overuse or burnout without effectively addressing the fire's primary threats. Therefore, the chosen strategy of continuing to flow water while reorganizing resources is tactically sound and aligned with fireground safety protocols.