The cable shovel is a critical component of production in the Athabasca oil sands. Random occurrence of shales, dolomites and limestones in this formation causes random high digging resistance which result in high maintenance costs. This paper contributes to the development of an intelligent navigation technology by developing a geometric simulation methodology for determining the resistive force on the shovel dipper due to the loaded material during excavation. The spatial dynamics of the shovel are modeled using ordinary differential equations and solved using a single step, explicit Runge-Kutta numerical algorithm. Simulation results show that depth of cut increases with an increase in crowd arm extension speed and a decrease in hoist rope retraction speed and that the rate of digging and mechanical loading is proportional to the crowd arm extension and/or hoist rope retraction speed. Using these results, engineers can parameterize the shovel excavation scheme for optimum performance.