Not locating the hinge and latch points on a vertical support is asking for trouble.

this is funny, no columns or cables, but also no brains, look it up, CauCau Bridge in Chile

"Drawbridge" is the term that is escaping you. Several Impressionists had them as subjects. The Dutch still are big on modern strange (but attractive) versions, but I am not aware on any that fit what you are looking for. The "leaf' can be two sections and meet in the middle, or a single leaf and hinged on one side only.

Not sure what you mean by "mechanisms not supported by pillars" but I'm gonna use this as an excuse to mention the Gateshead Millennium Bridge (currently doing a structural analysis project on it).  

The bridge is supported on either side by steel cylinders which are anchored into pile caps.  The cylinders have "paddles" underneath which are pushed by hydraulic rams, rotating the entire bridge and creating space for ships to pass under.  The deck is suspended from an arch-shaped steel box girder.  What makes this bridge especially interesting is that, as it rotates, the load path changes completely.

Thanks everyone for your contributions.

What I mean by "mechanisms not supported by pillars" is the  pivot point/s  and locking point/s joining the 'swing' or 'draw' bridge of the main bridge on the artist's impression are not above the pillars built into the riverbed.  The actual section of movable bridge has to allow for masts as opposed to above-hull structure.

I hope this makes sense.  I had hoped the artist's impression might be online, but appears not to be.

You could check out swing bridges.  They don't raise, rather they turn on a central pivot. 

http://chicagoloopbridges.com/

Sounds like you are describing the typical Chicago River Bridge. The bridge is an arm projecting from a huge gear located below the street almost touching the water.

Hope this helps.

Peter N