...I think I reasoned this out at some point in the past, but it didn't make to my AU project 'Unique Technology' chapter for some reason. I'll try to find the original notebook, but my kids think daddy's books are there to play with and rip up for confetti, so I can't promise anything.
If I remember right, it used either the center or side torso to mount another arm, basically. I had calculated IS weight for a single arm (Leg from a quad of the same tonnage?), and used Arm crits (Shoulder and upper arm, or Shoulder, upper arm, and lower arm). Firing arc was the rear arc but longer arms with more crits could use roughly the same arc as L/R. Given the impossibility of it all, it was energy weapon only. The 'tail' didn't give any benefit to moving in water as it was already absurd.
