What is a critical step after noticing a blockage at the strainer?

When a blockage at the strainer is observed, the critical step involves addressing the blockage to ensure that water can continue to flow effectively. Cleaning the strainer or directing water at it allows for the removal of debris that could hinder the performance of the water supply system. This action not only maintains the efficiency of the pump but also ensures that the apparatus can operate reliably during firefighting operations.

By taking this step, personnel are actively working to restore optimal functioning of the equipment, which is essential in emergency situations where time and effective response are crucial. Cleaning or clearing the strainer will help prevent overheating of the pump, potential damage to the equipment, and reduced water flow to fight the fire.

The other options, while they might seem relevant, do not directly address the immediate issue of the blockage and would not be the best initial response. Notifying command, replacing the strainer, or stopping operations might be necessary steps depending on the situation, but they are reactive rather than proactive when it comes to ensuring the ongoing functionality of the pump system amid a blockage. Thus, focusing on cleaning the strainer or directing water at it is the most appropriate and effective action to take in this scenario.