We have lots of those tire tanks. Look much like what Yanuk posted. They are huge equipment tires used in the coal mines in WY. Ours have been cut before we get them. Never got one free, tho!
Don't know what floats, or quite how we do them, as I haven't been involved and didn't pay attention., but could ask if anyone wants more ideals.
We have pretty remote locations, running our own waterlines off the rural water supply lines, so have to make them pretty trouble free.....and they have been.
Someone locally makes concrete lids, with about three drink holes in them. I think we baffle them somehow and have had very little, mostly no, trouble with them freezing....even at -30% a few days this past winter.
No additional heating, either. Just water out of the Mo. river, piped many miles to us, coming 'the long way round' instead of direct to the nearest point of the river from us. Line goes south from Pierre area, west to Kadoka, and back north and east to us. We live about due west of the intake, I believe, or maybe a bit south of west. And at least 50 miles distant.
The rural water has been a true Godsend for us. We could not have maintained the cattle numbers we did during the 8 years of drought without the rural water. We had a bit of grass, but NO water in summer pastures. Got lots of dams filled, or at least partially so during 2.5" rain in Feb. while ground was frozen. Have enough ground moisture now, to get the grass going again, so mother nature, more accurately, God, is better to us this year than our government intends to be, it seems.
mrj