Yes the bottom tanks are strutted to the decouplers as well as to the immediately surrounding tanks. They are also strutted to the upper piece that I'm launching. I'm lifting a huge payload - one of 2 attachments to my fuel station. It's the equivalent of 6 full orange fuel tanks. I tried locking the gimbals of all of the outermost tanks but that didn't work - however I only tried that once. Prior to this I haven't really messed with gimbals because I'm not that familiar with what they do and how they work. I'll try replacing the decouplers if nothing else works. Personally I believe those tanks are as strutted as they can be. I've only been playing for a few weeks, but I've got the grey tanks strutted to orange, orange strutted to surrounding tanks as well as to the decoupler itself and even the main body of the craft. I doubt G's are a problem because, as you pointed out, I'm still in the green and this beast is HEAVY. Frankly I'm not certain I'd get into orbit even I can prevent the orange tanks from splintering off, but I'm trying to exhaust my efforts before I start removing fuel. I'll take a look. I'm already set up with asparagus staging on this craft but maybe some plates and i-beams are what I need. Going to watch the vid now and see what I can take away from it. Thanks so much for all of the replies! I'll update when I have some results, good or bad.