Perhaps you need it as an authentic rescue dummy to practice hauling out of wells, basements, cliffs and caves?
While in the Fire Brigade we used a similar thing for realistically weighted rescue dummys. The one we had was filled with sand. Got a tad heavy when it got wet too!
Close enough , I want it for that , a few other purposes and to act as a realistic Wing Chun / Bob type striking dummy for Krav Maga practice.
http://graldinemay.girlshopes.com/bobpunchingdummy/