We report a fiber optic vibration sensor developed from a Fiber Bragg Grating (FBG) sensor. Three FBG vibration sensors are constructed and subjected to drop test, vibration test and mock train-railway positioning test. All the Bragg wavelengths of the sensors, as well as the Fast Fourier Transform (FFT) graphs are recorded by a computer via an FBG interrogator. Two commercial FBG vibration sensors are also tested for comparison. The results show that the fabricated sensors are robust, pick up low frequency vibrations, and detect a mini train position on a railway simulation.