Pawl and ratchet can keep the crane safe from accidental drops. Different gear ratios can make the lifting faster or slower and stronger. Counter weights keep cranes from falling over when lifting a heavy load.
Webpages and pictures on http://www.marshall.edu/LEGO Web camera on http://legocamera.marshall.edu Teleoperate AppaLEGO CITY at http://lego.marshall.edu NASA site of Remote Sensing on http://SENSORSCITY.marshall.edu