Clarence Street Bridge
The Clarence Street Bridge (also known as Bridge 21 ) is a lift bridge in Port Colborne , Ontario .
The bridge was built between 1927 and 1929 when the Welland Canal was being built and to this day it is an important link between East and West Port Colborne. The structure uses simple electric motors and counterweights to raise the deck 36.5 meters above passing ships. Raising and lowering the bridge takes about 90 seconds. This bridge is one of only four remaining road bridges with a vertical elevator over the Welland Canal.