The current paper implementates a simple fully non-linear Kirchhoff-lovel shell penalty based finite element. The 6 nodes and 21 DoF triangular element developed in this work has a quadratic displacement field associated to it and the C1 continuity required by Kirchhoff-Love Hyphotesis is approximated by an internal penalty. The biggest novelty in this article is the simultaneous use of penalty and a Rodrigues incremental Rotation parameter (scalar DOF) between neighboring elements further explained in the text. The nonlinear finite element model developed in this article is compared to analytical results, commercial finite element code and another FEM model developed in bibliography. Simulations have demonstrated consistency when comparing results to other models and it is deemed that reliable mesh generation together with a powerfull triangular finite element is a good option for trustworthy thin shell simulations.