Anim8or Community

I have a cylinder mesh that's roughly 300 meters long and 100 wide, it's a closed single wall.  The ends are covered in a lathed mesh.  What I'd like to do is make a double walled tank by copying the mesh, reducing it by 95% and importing it into the larger tank.  The tricky part to me is making three 10 meter wide cylinders for hatches and connecting them to the tanks so they stay hollow.     I'm working on some pods for a Star Trek Ptolemy class tug. 

  Thanks!

         ChristopherT