rudder trunk

I need answers of the following questions:

1)What's the necessity of rudder trunk?
2)What type of shape it is?
3)How it is attached with hull and rudder stock?
4)Is it possible to use Jumping clamp as alternative of rudder trunk?
5) Which book/article/standard contains a clear view/idea about rudder trunk?

In my case the distance between rudder main coupling and lower bearing is 344mm.

 

As a senior Naval Architect the structural part should not be a problem. A typical design is a what looks like a centerboard trunk but that rotates to steer. The blade can be raised and lowered for water depth or to balance the CLR