Wireless battery-powered sensor Eurosens Degree BT suits well this application. It has special operation mode - "Excavator".
Sensor is compatible with a popular GPS trackers like Teltonika, Galileosky, Smart (Navtelecom), Neomatica.
You can attach the sensor on the manipulator, crane or loader arm and it will register the movement activity. In the sensor setting uou can set up the time delay between movements.