If you can walk on the ice it will support a large ice shanty, it gets down to pounds per square inch. The problem may lie in the vehicle used to place the shanty on the ice. A snowmobile with place less pounds per square inch the a ATV due to the track of a snowmobile in relation to each single tire of a ATV. It's interesting that a discussion about pounds per square inch came up last winter with a Mennonite friend of mine as we stood by the pond that I had stocked fat head minnows in. It had about four inches of new clear hard ice on it, he asked me if I would walk on it and I stated that would be no problem, he then asked if I would drive my 2002 pickup on it and I stated "no way", he laughed and said he would be right back, he came from the barn with his "older than dirt" Cat D-4 and drove that sucker right out on the pond, turned around and drove it off. He then jumped down and gave me a quick course in math that I still don't fully understand, he attempted to show me that my feet placed more pounds per square inch on the ice than his old dozer. Couldn't argue with him as he had just drove a dozer on 4 inches of ice and all was dry. In summation: Howard is one of the most intelligent people that I have ever met and correct my English from time to time. To all, have a great hardwater season !!!!!