joining hulls

I am considering the construction of a large catamaran.

In principle I would like to make a single matrix for each of the two hulls using foam sandwich.
Then Id like to join the two hulls in a way that does not requiere extending the two hulls but rather use sever beams. On top of the beams I would lay the deck and superstructure.

Is this possible or is it structuraly unsound?

thx, the catnut

 

It can be done, and has been done, but for a "large catamaran" you will want an engineer or NA. There are huge forces and strange twisting moments in unexpected directions, when you look at what goes on in the crossbeams of a cat. Careful design (with BIG safety factors) of the cross bracing is needed to ensure the boat doesn't simply snap in half.