Which pumper has the largest capacity during a relay operation?

In a relay operation, the source pumper plays a critical role as it is responsible for drawing water from a static water source, such as a pond, river, or reservoir. This pumper needs to have the largest capacity to ensure a sufficient and continuous supply of water for the entire operation. By having the capability to transfer more water over longer distances, the source pumper can support the on-scene pumper effectively during emergencies, especially in situations where water needs to be transported to a location far from the water source.

The other pumpers involved in the operation have different roles. The on-scene pumper is tasked with delivering water directly to the fire scene but depends on the source pumper to maintain an adequate water supply. The backup pumper usually serves as a secondary unit in case of equipment failure and does not typically need the highest capacity for primary water delivery, while the pumper with the most water may not specifically refer to its functional role or capacity related to the relay strategy during an operation. Thus, the source pumper's role and capabilities are essential to ensuring the success of a relay operation.