The Lewisville Lake Toll Bridge’s (LLTB) signature 360-foot tied steel arch continues to take shape with the addition of the arch’s corner knuckle pieces. Each knuckle is 28 feet long, 16 feet high, 4 feet wide and weighs 93,000 pounds. The pleasant weather during the first half of January allowed the crew to finish the placement of the three remaining knuckles.

 

Crews then began placing the tie beams that form the 360-foot base of the arch. Each tie beam is made of three pieces. Two pieces are 83 feet long and one is 105 feet long. The total weight of all three pieces combined is approximately 230 tons. The pieces are hoisted into place using a large crane mounted to a barge, which is moored in place. The boom towers over the crane approximately 125 feet into the air as it sets each piece in place. The steel pieces are connected with one-inch diameter bolts. Some connections use more than 1,000 bolts.

 

The heaviest individual piece is an arch rib weighing 95 tons. With such large steel pieces being lifted more than five stories above an open body of water, safety is of the utmost importance. Each day the crew exercises routine safety practices, including equipment and job site safety inspections. The steel beams are so heavy that winds of 5 to10 mph are not likely to cause the beams to shift while they are being placed. When wind speeds are gusting around 20 to 30 mph, however, the crew does not lift or set new pieces. Safety is a priority on the job site and when the wind speeds are too high to work on the arch, there is plenty of other work to be done on the other parts of the bridge, such as the concrete decking and construction of the toll gantry.

 

When complete, the arch structure will soar 118 feet above the lake surface and be illuminated and tied together 58 feet above bridge traffic. The massive arch structure currently taking shape will soon become an easily recognizable landmark in southern Denton County as it connects the communities of Lake Dallas and Little Elm. The LLTB is on schedule to open to traffic in the third quarter of this year and is part of a larger corridor north of Dallas that will link IH 35E in Lake Dallas to the Dallas North Tollway in Frisco.