madcap...i like the rope tensioning idea! i've never had a problem with just the one anchor and my sled moving around...it did cross my mind when intially incorporating this anchor tho. it has been proven (one foolish day out) to take about 50mph gusts...needless to say i didnt stand it for very long tho. I think this is a must for any shelter owner, seen to many shelters destroyed plus tackle when their sled takes off across the ice for miles!