Spring Hollow Reservoir Intake Tower - Salem, Va.
State of Virginia
Ibberson was awarded the contract to provide slipform equipment and labor services for the intake tower. General contractor PCL originally scheduled 8 to 10 weeks to construct the 220‑ft. intake tower for this reservoir project, using the conventional “gang” jump-form building method. However, the company’s strategy changed when they experienced unforeseen project delays. Ibberson was called in because of its slipform expertise, and the intake tower was completed on schedule.
Ibberson’s crew mobilized and assembled forms to create a 3-in.-thick wall with a 6-in. setback at 152 ft. For nine days, the crew poured concrete 24 hours a day. Within six weeks from arriving on site, forms were stripped and the intake tower was completed.
The intake tower extends the full height of the dam and contains a series of vertically-arranged slough gates that allow water to be tapped off at different levels. Ibberson’s design allowed the placement of the 4,000- to 6,000-lb. gates through 24-ft. by 14-ft. openings constructed in the upper deck, without having to shut down the slipform operation.