Wicket Gate Repair Made Easier with a Climax Boring Machine.

“ Climax helped us figure out a way to mount the boring machine so it was able to fit all the units we were working on.” 
- George Foley, Hydroelectric Mechanic Supervisor II, U.S. Bureau of Reclamation.

Hoover Dam: a massive facility allowing for miniscule margins of error.

The U.S. Bureau of Reclamation is responsible for the operation and maintenance of Hoover Dam, whose 17 main turbines generate more than four billion kilowatt-hours of hydroelectric power for California, Arizona and Nevada. The Bureau performs repairs on one or two turbines during a scheduled outage each year.

A Climax boring machine has made the job of line-boring the bushings on each turbine’s 24 wicket gates a lot easier.

The maintenance team’s technique is to install the bushings too small, and then bore them out so they can get an aligned fit. Since only .015 to .018 inch (.381 to .457 mm) clearance exists top and bottom, aligning the holes for a precision fit is essential to proper gate performance, but it’s a tricky task. The concrete has settled since Hoover Dam was built in 1934, making it no longer possible to align a boring bar simply by centering it between the top and bottom holes.

Frustrated by a number of inadequate and awkward previous efforts to achieve precise bushing alignment, George Foley, Hydroelectric Mechanic Supervisor II, discovered a better solution in a tool that had been ordered for another project: the Climax BB6000 Boring Machine. “Climax helped us to figure out a way to mount the boring machine so it was able to fit all the units we were working on,” Foley says. 

A straight line at last

Using a plumb wire system to achieve proper vertical alignment, his crews were able to use the portable tool to line bore bushings and also size and align the new stainless steel plates between the wicket gates. “The three bushings have about 64 inches (1625.6 mm) from top to bottom,” Foley explains, “and we’re able to keep them plumb within two thousandths of an inch (.0508 mm) or less. That’s a pretty straight hole.”

Speed is also important. The crew is able to finish one set of bushings in two shifts, or about 20 hours total, with the machine running continually. Hydroelectric Mechanic Jim Patmore appreciates the easy set up. “Once you’ve lined it up in the proper position and locked it down,” he says, “you just need to dial out the size you want, and the bar is going to cut exactly where you want it.”