In this report, the computational modelling of thin-walled steel sections is implemented by means of a spline finite strip analysis to determine the elastic buckling stresses of channel sections subject to pure shear. Lipped channels with an intermediate web stiffener are studied where the main variables are the dimensions of the stiffener in both depth and width directions. Results and comparisons of analyses are included in this report. University of Sydney Research Report R892, Sep 2008, by Pham, C.H. and Hancock, G.J.