Bridge Cranes are industrial equipments that to be used widely in many industrial fields and therefore, there are many researchs about control methods to control them. This paper offers a mathematical model of a simple bridge crane (two-dimensional form of the model that has been linearized) and the design results of a discrete Kalman state observer status for the 2-D crane. The state of the system, which is often overlooked, will contribute to improving the quality control system without additional hardware equipments, as well as the cost of equipments. The simulation results on MA TLAB - Simulink to verify the correctness of the algorithm that has been designed.