In this paper a low cost engine status monitoring system (Black Box) is described as a safety equipment to record all the data of railway engine WAP-7 with real date and time. A voice recorder is also used with this system for safety and investigation of accidents. There various types of sensors are used for measuring parameters of electric engine. In this system signal processing is done by microcontroller 89C52. This device having the 8 hours recording capability with real date ad time and operated at 5-12V with 3 ampere current ratings. Recorded data of memory can be retrieved by the HyperTerminal of PC.