The specific answer to this question may vary due to several factors, such as:

– The size of the HESCO barrier
– The capacity and efficiency of the front-end loader
– The type and availability of fill material
– The experience and skill of the operator

Typically, a skilled operator using appropriate equipment might need anywhere from a few minutes to several tens of minutes to fill a standard-sized HESCO barrier unit. However, completing an entire defensive structure could take hours or even days, depending on the required length and height of the barrier.