Seeing this is really helping me to appreciate what I could do to change the Constitution's design to make it more realistic and perhaps even a better looking ship. I really believe Shape should follow function and this might be an interesting part of the ship that could be altered to better suit it's needs.
I always felt the base of that neck need alot more girth in width for the loads it was carrying.
I kept thinking about having the supports run singly into the secondary hull structure; but, instead ended up deciding for a solid base that the structure would weld to. I felt like that would act as a stiffener at the hull connections.
But, I also went with a 12 inch beam instead of the apparrent 6 or 8 inch beams suggested by the everhart drawings. I did this before consulting Everhart essentially because I felt that any smaller would simply not be sufficient for the stresses you mentioned.
I also did a full beam instead of I-beams. I figured these columns should be more like the support columns at the base of a building - hollow core and thick walls. But I also imagine that a lot is going to rest in the nature of the materials used. These are going to be alloys that like a samurai blade allow for a mix of rigidity and flexibility.
This seems an under-appreciated idea from my point of view.. that the materials make a difference. That said, one need only look at the effect that things like titanium and carbon fibre has had on the building of all sort of things.
These materials have allowed us to make things like dragster frames that both require less of the material, provide a lighter weight frame and a more rigid and strong frame at the same time. Carbon fibre extends that even further. So next gen materials should extend this concept even further.
That said, much has to be assumed of the materials as there is no deliniation made of what the realworld tolerances of those materials might be. The buildup I have put forward for the dorsal section, were it for a stationary structure, would be pretty massive overkill. I like what Drexler did with his cutaway; but, FJ did'n't allow space to do that here. And to be honest, I'm not really certain I like the amount of space or construction dedicated to the connection at the primary hull. I'll do what I can to make the available structure do the job intended; but, I don't imagine that will look less like magic and more realistic in the end. It's annoying; but, there's only so much that license will allow one to get away with sometimes.