Strauss Heel Trunnion Bridge

2010

Strauss Heel Trunnion Bridge

 
 

This are pictures of the blue bridge in Victoria B.C., and the Cherry St. Bridge in Toronto Ontario. 

The Johnson Street Bridge was opened in 1924, designed by Joseph Strauss (of Golden Gate bridge fame). This Bascule bridge has two separate parts, a train bridge , and a roadway bridge (also used for bicycles) - the only one like this ever made! As you can see, there is a heavy counterweight on one side, which makes the lifting of the bridge easier, so less energy is needed. The 780 ton counterweight is placed so that as the bridge lifts, the weight of the span (road) moves closer to the fulcrum (the span weighs 350 tons), and gets lighter, the counterweight also moves closer to the fulcrum and the weight relative to the road stays balanced - nice!

For more information about the bridge and the current controversy surrounding it check out this site: http://johnsonstreetbridge.org/

The Cherry Street Bridge was built in 1931 and is located in the harbour of Toronto, spanning a long ship channel. The counterweights are split on this bridge and are at each side, with a total weight of 750 tons. Refurbished in 2007, the paint is already peeling off and rust setting in (in 2010), so get out there and have a look before it rusts out! Not all Bascule bridges have decayed so badly, the Strauss Heel Bascule bridge in Ashtabula Ohio , and the Mystic Bridge in Connecticut are examples of bridges that have been taken care of.

Check out the Youtube videos of these types of bridges, there are lots!