The main challenge of the project was constructing the two bridges on a 45 degree skew, 120 ft. (36.6 m) in the air over a tributary of the Big Bear Lake Reservoir.
Wright Brothers Construction Co., Inc. of Charleston, Tennessee was awarded a $15.8 million contract to build a set of north and southbound bridges 1,110 ft. (338.3 m) long for a by-pass running from U.S. Highway 43 to Highway 179, in the northwestern corner of Alabama.
The main challenge of the project was constructing the two bridges on a 45 degree skew, 120 ft. (36.6 m) in the air over a tributary of the Big Bear Lake Reservoir in Phil Campbell, Alabama.
With just 50 ft. (15.2 m) of right-of-way on either side of the new road, crews had to determine a method for access, storage and delivery of multiple bridge beams. The two bridges are composed of fifteen 135 feet (41.1 m) long, 72 in (1.8 m) bulb-tee girders; seven spans for northbound and eight spans for southbound lanes. The fifteen beams, each weighing 60-tons (54.4 mt) were placed on concrete reinforced piers.
As operator Chance Kelley puts it, the two 200-ton (181.44 mt) lattice crawler cranes responsible for the lifts, a Link-Belt 248 HSL and 248 H5, were ideal candidates.
“They're solid, and the most important thing you can have in a machine is control over the load. When you are working on a skew, you have to be more cautious, we do not have the ground space needed to make placing on a skew easy; you can only go out into the creek so far. The later beams became more critical to place since I couldn't go further south into the creek. When I have to swing the girder out over the pier cap, the girder itself is close to my boom – even as I swing it away from the boom. At the same time, I'm approaching the cap that I'm swinging toward for beam placement,” said Kelley.
For Kelley and the rest of his crew on the ground and 120 ft. (36.6 m) above him at the final resting spot for each of the beams, communication is crucial.
“I have two things in this case that I have to constantly watch for, the cap and the beam. That's when I rely on my flagger, construction manager Chris Brown. He knows exactly how much or how far to keep my boom off of the cap until ready to set it in place,” added Kelley.
The seven most critical girders were placed over the course of two days – four girders the first day and the remaining three the following day. Girders of this size are not allowed to travel over Alabama highways during daylight hours, so they were transported 115 miles (185 km), from Phil Campbell in Pelham, Alabama at 2 a.m. EST and arrive at the jobsite by dawn.
Once there, the two Link-Belt Cranes, in tandem, travelled with about 30 tons (27.2 mt) of girder each from pick-up to where the beams are placed more than 114 ft. (34.7 m) above the pier footers.
A temporary bridge was constructed for the 248 HSL in order for it to cross the creek. The south side of the embankment was stepped back, allowing just enough room for the 248 HSL with its tight 16 ft. 10.76 in (5.15 m) tail swing to travel 150 ft. (45.7 m) from the temporary bridge where the beams are transported, to the large 18 ft. (5.4 m) wide by 8 ft. (2.4 m) deep columned pier.
Link-Belt Construction Equipment Company, with headquarters in Lexington, Kentucky, USA, is a leader in the design and manufacture of telescopic boom and lattice boom cranes for the construction industry worldwide.
For more information, visit www.linkbelt.com.
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