Very well said Huntindog . What I have noticed after reading the rv forums , race car forums and some fishing forums ,is that those who have experienced numerous failures on tires on trailers and switched to the LT tire share their experiences to possibly help the next guy avoid what you described in your post .
As far as the Hercules tires , thats what my 10K rated rv came with when I bought it used . They had plenty of tread and 5 years old, but I went the 16 in and LT route on the RV . BUT I put those tires on a tow behind diesel compressor that weighs 1800 lbs , I run local 40 mph roads , no highway and only in the fall to winterize irrigation systems . BOTH tires threw the treads off . They still held air for some dumb reason , I had to leave the compressor in a parking lot and get my car trailer to retrieve it . If they are making them better , good. But once burned twice careful .