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Arnold AFB crane and rigging crew supports annual Elk River Dam maintenance

  • Published
  • By Bradley Hicks
  • AEDC Public Affairs

Members of the Arnold Air Force Base crane and rigging crew spend much of their winters on the lake.

Sure, it can get chilly; at times, uncomfortably frigid, but the crew’s annual wintertime stretch at Woods Reservoir is necessary to ensure components imperative to base operations remain in working order.

The crew recently supported a yearly preventative maintenance project at Elk River Dam. The dam impounds the approximately 4,000-acre Woods Reservoir, which serves as the source of water for Arnold AFB, headquarters of Arnold Engineering Development Complex. Water from Woods Reservoir is used at the base for cooling test cells, fire protection, sanitation and drinking.

Upkeep on the three large tainter gates, two sluice gates and the leaf gate of Elk River Dam must be completed annually. The curved tainter gates, also known as radial gates, control water flow from and provide storage within the dam. Sluice gates release water to help control water levels in Woods Reservoir, and the leaf gate helps control the water flowing from the reservoir to Elk River Dam.

The work must be performed during the winter months, as this is when the endangered gray bats that reside at the dam for most of the year migrate to caves to hibernate.

“This requires a lot of work to be accomplished in about a three-month period which also happens to be in the middle of the winter, which exposes the workers to some of the most extreme cold periods of the year,” said Jason Farris, Operations and Maintenance Superintendent Manager for the AEDC Test Operations and Sustainment contractor.

Crews received word that the last two bats had departed the dam in early December.

“All gates were inspected quickly, effectively and well before the end of the three-month work window,” said Tyler Swann, Air Force Utility Asset Owner and Dam Manager. “Preventative maintenance was executed while having a very late-start opportunity.”

Stoplogs must be installed in each of the three tainter gates to block off the water and allow the gate to be cycled while the trunnion pins, which are the points at which tainter gates pivot when opening and closing, and other mechanical equipment are lubricated and checked for proper operation. Each gate must be cycled fully open to fully closed several times.

The gates cannot be opened in this manner without the necessary precautions, as a single gate can release more than 25,000 cubic feet of water per second. The normal flood stage is 5,000 cubic feet per second, so operating the gates without the stoplogs installed would cause significant flooding downstream.

“Cycling the gate is part of ensuring reliability, so the routine of installing the stoplogs is critical to that process,” Farris said. “While the stoplogs are installed, it allows a chance for visual inspection of the gates and spillways so any problems can be caught early and repaired.”

Workers also inspect and maintain the hydraulic systems that operate the sluice gates and leaf gate. They also test and perform maintenance on the gate control systems.

Each year, after all the work is completed, the crew inspects and repairs the stoplogs to get them ready for use the following year.

The work provided by the crane and rigging crew at Elk River Dam supports one of a number of preventative maintenance projects overseen by Base Civil Engineering.

“We provided over 1,600 manhours to this effort with no accident,” Farris said. “This in itself was no accident. It was because of the crew’s focus on safety in each and every task daily.”