This document summarizes a survey on using cluster-based data aggregation techniques in wireless sensor networks for railway track monitoring. It discusses how WSNs can be used to automatically monitor tracks and reduce human inspection needs. It reviews different data aggregation approaches that combine data to reduce redundancy and transmission costs. In particular, it examines the Low Energy Adaptive Clustering Hierarchy (LEACH) protocol, which forms clusters to perform in-network data processing and transmit aggregated data to sinks. Using this clustering approach can achieve high accuracy, reduce energy consumption, and prolong the lifetime of WSNs for railway track condition monitoring.