1. The problem statement, all variables and given/known data A framework of pin jointed members has to be designed to support a plug introduced into the reservoir wall to prevent leakage and further progression of a crack along the wall. The plug is cylindrical, has a diameter of 0.35 m and is supported by a single pin joint. The frame is anchored to the ground using a pin joint and a roller joint. Firstly, design the simplest framework to hold the plug in place. The problem is to be presented and solved as a system of equations using MathCAD. 2. Relevant equations It is deriving the equations on the joints and beams that I am having trouble with. 3. The attempt at a solution So far I have a diagram of the frame work: and have worked out the force that is being excerted on the plug: But I'm having trouble comming up with the 6 equations involving (F1, F2, F3, H2, V2 and V3). Now I think all of the equations will be equal to 0, apart from the sum of the vertical forces in joint 1 which will be equal to 9808 N, and the sum of the horizontal components in joint 1 which will be equal to 5663 N. Apart from that I'm at a loss and don't really understand how to get the equations. Any help would be greatley appreciated.