Vertical Lift Bridge?

[jali]

Clayton_e's question sparked a memory from childhood and I found a picture and I know the name, but what is the purpose of a vertical lift bridge?

farm2.static.flickr.com/1339/1406491165_c7fae343d8.jpg?v=0

[Harmonious Discord]

It's so something can go under the bridge that needs to get by.

Low clearance of water when bridge down.
Note the low clearance over the water in the Duluth harbor bridge. you don't have to deal with a weight swinging on the other end.
Dulth harbor aerial lift bridge.

[Dragon]

Rail was installed long ago. Cheaper to build a lift than to build usable ramps for rail. they can have near the grade of a auto bridge.
Rail crossings are usually on a regular schedule and not needed constantly like highways.

Mostly because it is cheaper and more efficient in those applications.

[jali]

Thank you.

We passed the vertical lift while driving on the Goethal's Bridge, and I was afraid that one day, my dad would choose the wrong ramp and we'd end up stuck in the middle of the river. Forever. I was about 6 years old, and I never asked my parents, since I thought staying quiet would keep us safe.

[Suburban Plankton]

It's just a 'drawbridge', but not in the traditional sense. We have one here in Sacramento, too

Tower Bridge

And just about half a mile upstream from that one, we have a bridge that rotates instead of lifting.

I Street Bridge