Abstract: An automatic or movable bridge is a special type of bridge that moves to allow passage (usually) for boats or large ships. In this project automatic bridge is fully automated by using PLC. Automatic bridge is operated in countries like United Kingdom, United States of America and Howrah Bridge in India. The main objective of this project is to allow passage to huge gigantic cargo ships on the canals or lagoons because for them bridge can't be build because of their shape and size. The idea is to automate the process of ship detection, opening or closing of a bridge, controlling the signals and road barriers. The purpose of the research is to replace the manual system which is currently used. The ABB PLC is used to mechanize the system. Sensors such as Proximity are used to provide input to the system. And motor such as servo and DC motor serves as an output. Ladder diagram as a programming language is used to control the whole system between the input and output. With the help of Ultrasonic sensor, Proximity sensor the arrival and leaving of the system is Monitored and bridge is operated accordingly.
Keywords: PLC, Drawbridge Modal, Proximity Sensor, Ladder Logic.