![](https://sdi.wpsitekeep.com/wp-content/uploads/2016/11/19_pearl_ridge_monorail_aiea_hawaii_1.jpg)
Pearl Ridge
The Pearl Ridge Monorail in Hawaii has had a long and successful service life, but having been built on 1970s technology, the system needed upgrades to meet today’s new technology and standards. SDI completed upgrades to the train’s on-board and wayside controls, propulsion/braking system, door drive system and installed a new emergency recover system, improving the system’s passenger safety and reliability.