Forces in a pole

How do you calculate the forces inside a pole?

We (some students) are having trouble with a assignment.

Link to pic will come momentarily.

http://img127.imageshack.us/img127/9080/poleshb0.png

The object of the assignment is to calculate the forces that travel down the 'poles' in this construction.

Looks pretty standard. Rigid unmoving structure, right? Then the sum of the forces on any junction and beam must be 0 (or it would move), and the total force on any beam end should be parallel to that beam (or it would rotate).
That should get a you a nice, boring set of equations to solve. (And note that the forces should turn out symmetric.)
E.g.
F1_y + R_y + F_S11y + F_S21y = 0

We know that, but we need to know how to calculate the forces in s1 and s2 etc...
 

The forces 'in' s1?
For any small segment of s1, the forces on it should be the same as the forces on s1's endpoints, unless there are properties in your model that you haven't described.

Poles are stupid, hence all the jokes about them