Conditions of the Tripod Limiting Equilibrium on a Horizontal Plane with Friction

The problem of limiting equilibrium of a heavy rigid body resting with three points on a horizontal plane with Coulomb friction (tripod) is considered. The body can be brought out of the state of limiting equilibrium by the shift torque of a couple of active forces lying in the support plane, i. e., by the torque whose value does not disturb the equilibrium of the body but, when the torque takes a greater value, equilibrium is broken. The maximum value of the torque of friction forces in the supports, counteracting the shift torque, is found.