Abstract: An effi cient electromagnetic energy harvester featured with mechanical motion rectifi er (MMR) is designed to recover energy from the vibration-like railroad track defl ections induced by passing trains. Trackside electrical infrastructures for safety and monitoring typically require a power supply of 10-100 Watts, such as warning signals, switches, and health monitoring systems, while typical existing vibration energy harvester technologies can only harvest sub-watts or milliwatts power. The proposed harvester is designed to power major track-side accessories and possibly make railroad independent from national grid. To achieve such a goal we implement the MMR, a patented motion conversion mechanism which transforms pulse-like bidirectional linear vibration into unidirectional rotational motion at a high effi ciency. The single-shaft MMR design further improved our previously developed motion mechanism, increased energy harvester effi ciency and expanded power harvesting potential. The proposed new design improved reliability, effi ciency, and provided steadier power output. Bench test of the harvester prototype illustrated the advantages of the MMR based harvester, including up to 71% mechanical effi ciency.