Fraco goes to work on slanted, 220-foot dam

Fraco Products Ltd was recently called upon with American Hydro, a hydrodemolition company, to install mast climbers on a 220-foot-tall dam in San Diego, CA to raise the height of the dam.

The San Vicente Dam needed two and three inches of its dry side removed to create a bonding surface for 800,000 cubic yards of new roller-compacted concrete and conventional concrete, which will put the dam at a total of 337 feet high.

In order to complete these tasks, Fraco installed mast sections on the inclined concrete face of the San Vicente Dam, but not without slight complications.

"The first mast section plcement to the far left took four days [to install] as the dam is not quite flat as it was supposed to be; conditions changed as each 30-foot mast was flown into place," said Tim Riley, Fraco's Southern California representative.

"The second layout of mast took about two days with some fine tuning of the custom shims. We installed the third mast section in one day as we built the mast on the ground and copied the shim and space brackets to match the second install."

After the three rails were in place, American Hydro came in and started the concrete removal process. As each section was worked on, the mast sections were moved to another area of the dam. The process is expected to be completed by the end of April 2010, Fraco says.

The entire $568 million project is one-of-a-kind - the dam raise is the tallest in the US and the tallest of its type in the world. Work started in 2009 and is expected to finish up in 2012.