How many external fill connections must an MWS apparatus have?

An MWS (Mobile Water Supply) apparatus must have at least one external fill connection to ensure that it can be refilled from a municipal or alternative water source. This capability is crucial for maintaining an adequate water supply during firefighting operations, especially in areas where water sources are limited. Having at least one external fill connection allows for efficient refilling without having to rely solely on internal water tanks, enabling quicker response times and sustained operations. Without this minimum requirement, the effectiveness of the MWS would be significantly compromised in providing continuous water supply in emergency situations.