Plumbing the Only Traditional Building System at Mountain Lodge

By Consulting Specifying Engineer Staff September 28, 2006

Reached only by strenuous hike, LeConte Lodge in Great Smoky Mountains National Park has no electricity but offers other comforts such as hot meals and beds with blankets and clean sheets. Because of 23-year-old storage tanks made with Vipel resin technology available today through AOC, guests also enjoy running water.

At outdoor faucets, guests can fill canteens or splash down after the hike up. Some water is propane-heated to provide washbasin bathing, and the readily available water is essential to food and beverage preparation in the Lodge’s dining hall. However, one of the most welcome amenities running water offers is the availability of flush toilets.

The Lodge water system uses three fiber-reinforced polymer (FRP) composite tanks.The horizontal, aboveground tanks were airlifted by helicopter to the mountaintop in 1983 when the Lodge upgraded its water system and increased capacity 50% by replacing a redwood storage tank.

Virtually maintenance-free

“The composite tanks have been very dependable ever since they were installed,” said Tim Line, General Manager/Owner of the Lodge.“On occasion we’ve wiped off a film that naturally builds on the exterior over time, but that’s about the extent of any tank maintenance we’ve had to do.”

One of the composite units is a 6-ft. diameter, 3,000-gal. holding tank. The other two are 8-ft. diameter, 7,600-gal. supply tanks installed adjacent to one another.

The smaller holding tank is near the mountain’s ever-reliable Basin Spring. Spring water naturally accumulates in three adjacent collector units that feed the holding tank. Gravity-powered water from the holding tank activates the hydraulic ram of a pump that transfers water uphill through piping to the supply tanks. “For every ten gallons of water used to move the ram, one gallon is pumped up to the supply tanks,” Line pointed out. “The other nine gallons end up as Roaring Fork River miles downstream.”

When it is sunny enough, the ram can be activated using solar power. In rare cases when holding tank water levels run low and sunlight is insufficient, a gasoline-powered pump is available for back-up.

To create enough head pressure for good water flow, the two supply tanks are at an elevation higher than lodge facilities. To meet Tennessee State requirements, the water is batch-chlorinated through manholes atop the storage tanks. The Lodge water supply has consistently passed monthly state inspections and quarterly Park Service inspections for water quality.

At the end of the Lodge’s March through November season, the tanks are emptied for the winter when temperatures can drop to -20° F. The tanks also withstand total annual snowfall accumulations that can exceed 60 in., annual rainfall totals that can exceed 70 in., and high winds and debris.

How the tanks were made

The tanks were made by the former Tank Division of Owens Corning who sold the division to Containment Solutions, Inc., in 1995. Tank end caps and cylindrical shells were manufactured using a resin and chopped fiberglass spray-up process. The resin was an isopolyester engineered for potable water use by the Owens Corning Resins & Coatings Division, which became a co-founding partner of AOC.

Each tank has two exterior ribs that allow the tank to be supported by setting the ribs

The ribse shell wall.

To resist ultraviolet degradation, a UV inhibitor was incorporated into the resin for the exterior layers of the tank and ribs. For additional UV protection,

“The proven performance of Vipel resin at LeConte Lodge is a testament to AOC’s corrosion resin technology,” stated Emilio Oramas, AOC Business Manager for the corrosion market.“Today’s Vipel resin technology can offer the same combination of excellent corrosion resistance, structural properties and potable water code recognition.”