an incline elevator with a load carrying unit running on a u - shaped track . the load carrying unit is mounted on trucks engaging the track . below the trucks are swivelably mounted eccentric safety devices , with roller guides spring loaded against the interior walls of the channel , and eccentric brakes retracted during normal operation or extended during emergencies like a break in the elevator hoist cable . the eccentric brakes are retracted when both mechanically and electrically driven linkages are engaged . the brakes are retracted when tension is present in the hoist cable , and when electrical speed sensors sense an underspeed condition . the eccentric brakes deploy when either there is a hoist cable break , an overspeed condition , or an incline elevator power failure . the eccentric brakes are spring loaded to swing out , engaging the interior walls of the channel of the track , and jam in position stopping the load carrying unit .