Braddock dam almost travel-ready
Pittsburghers will be able to see by mid-July half of a dam being floated up the Ohio and Monongahela rivers.
The portion of the dam, which weighs 10,700 tons and is under construction in Leetsdale, will be taken to Braddock, where it will be installed as part of a $705 million lock and dam improvement project. The other part, which will weigh 8,600 tons, will be floated up the rivers later in the summer.
The journey from Leetsdale to Braddock will be slow. The dam will not travel faster than 5 mph at any point during the 26-mile trip, said Dick Dowling, public affairs representative for the Army Corps of Engineers, which is in charge of the project.
The dam will be fitted with necessary hardware in Duquesne before it is taken to Braddock. The dam will be floated in place above its final resting site, then slowly set down onto a foundation.
Workers plan to begin flooding the base of the dam on June 27. It will take about two weeks before the dam is buoyant enough to float up river.
The larger of the two dam segments will be 330 feet long and 100 feet wide. The other segment will be 265 feet long.
Once the dam is launched, it will leave a gaping hole in the Leetsdale Industrial park, where it is being built. That hole will be filled by more than 100,000 cubic yards of concrete rubble from Three Rivers Stadium, which was transported to the site earlier this year.
Because of the size of the dam project, the Army Corps of Engineers placed Web cameras at four locations: the Braddock Dam construction site, the archaeological area at Leetsdale, the Leetsdale construction site and a distant view of Locks and Dam 2 along the Monongahela River in Braddock.
People interested in the project’s progress can log on to the Web site www.lrp.usace.army.mil/webcam/essroc.htm for more information and Webcam photos updated regularly.
The Braddock Dam will cost $107 million and is part of a project that also includes new locks in Charleroi and the removal of locks and a dam in Elizabeth, said Tiffany Huff, public affairs representative for the corps.
The construction and transportation method is a first on any inland river, Dowling said.
‘It is similar to the type of construction that is used in North Sea oil platforms. That technology has been around for a few years, but to construct and install a dam in a flowing river has never been done,’ Dowling said. ‘We’re learning a lot – such things as site preparation, computing the weights and balance points for an 11,000-ton concrete block that has to float. That’s a tremendous challenge.’
Huff said future uses for the technology could include construction of bridge piers, docks, wharfs and especially river locks. This technique shaved more than a year off the construction period and could save between $5 million and $15 million, Huff said.
Mark Berton can be reached via E-mail at email@example.com .