Abstract: A mechanical propulsion system characterized by a housing, a number of power racks rigidly disposed within the housing, a load carriage coupled to the power racks for forward or reverse rotary thrust motion with recoil action, and means for driving the load carriage rearwardly during acceleration as the power carriage moves forwardly with the housing. Once the power carriage and a load carriage are in equilibrium, excess thrust is transferred to the housing and power carriage racks.