Thursday, April 5, 2007

Tacoma Narrows Bridge Expansion Joint

Bridges move. You may not always feel it, but bridges move. There are many engineering reasons for this, but engineers factor into their designs the need for a bridge to move.

The new Tacoma Narrows Bridge, the youngest sister to Galloping Gertie, who notoriously moved bridge engineering into the 21st century, has an expansion joint that weighs 100 tons and measures 70-feet long by 15-feet wide. The expansion joint makes it easier for bridges to move.

While the part is meant to help the bridge move, the part isn't moving. It was held at the state border on its way from the manufacturing plant in Minnesota to its final home in Tacoma.

That all should change this week. The experts are working out an appropriate trailer configuration and the expansion joint - along with its support caravan should roll toward Tacoma very soon. So many people have contacted us about this part that we have made sure you can watch its progress online.