Hot Axle Box Detector: a sleeper-mounted temperature detector, which warns a signal box of an overheated bearing as it counts the passing wheels. It indicates which axle is faulty and if one axle or wheel is hotter than the others on the train.
Hot Axle Box Detector: a sleeper-mounted temperature detector, which warns a signal box of an overheated bearing as it counts the passing wheels. It indicates which axle is faulty and if one axle or wheel is hotter than the others on the train.
