Rods are loaded or charged into a Rod Mill using a mechanised charger.  The rod charger with extendable boom moves rods safely inside the trommel/trunnion before charging with a typical 30 seconds or less cycle time per rod.

How you charging a rod mill is best explained by the video below.

http://heathandsherwood64.com/products/mpe/grinding and http://www.mclellanindustries.com/rodcharger.html sells them.