Once the bents are in place, it's time to bring on the beams. 

 

Over 90 feet long and about 60 tons, it takes a special truck to haul these behemoths to the job site.

 

 

 

You can steer from the rear (essential in tight quarters).

 

 

 

36" rims and a sun roof! What more could you want?

 

 

 

Roll it into position and hook up the shackles.

 

 

 

 

The Manitowoc 777 takes up the slack .....

 

 

 

..... and up it goes!

 

 

 

then swing it around ...... easy - -

 

 

and line it up ..... no sudden moves! Notice the welder on the left going about his work.

 

 

 

 

Ready

 

 

 

Line it up and watch your toes!

 

 

 

 

Give me some slack and unhook the shackles.

 

 

 

The beams rest on pad bearings and are welded to the top plate.

The beams need to flex under changing loads so they can't be rigidly attached to the bents or abutments. The rubber or neoprene pad permits this motion while supporting the vertical load. The slot in the top plate allows expansion and contraction of the beam.  

 

 

 

 

A place for every beam and every beam in its place.

The beams are prestressed concrete. Special high strength steel cables are held under very high tension while the concrete cures around them. The cables maintain the cured concrete in compression and results in a strong and durable beam. The ends of some of the cables are visible in a group near the top of the beam and in two groups left and right at the bottom. There is also some rebar exiting the ends of the beams at the bottom.

 

 

 

 

The Field of Beams!