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T-Mobile USA Inc.'s antennas are mounted to this steel water tank with a magnet-based system that withstands winds of up to 150 mph. Photo: Metal & Cable Corp.

By David Klein

PRODUCT OVERVIEW

OWNER | City of Steubenville (Ohio) Water District
CHALLENGE | Meet specifications for mounting 12 cellular antennas
PRODUCT | Magnemount Side-Tank Mount (M-STM)
MANUFACTURER | Metal & Cable Corp. Inc.
CONTRACTOR | Speelman Electric Inc.

As the cell phone industry continues growing, the competition for space on top of water tanks is increasing. Towers nationwide are beginning to bristle as providers vie for optimal signal positioning amid the logjam.

That's what the nation's fourth-largest wireless provider — T-Mobile USA Inc. of Bellevue, Wash. — faced as it prepared to install 12 antennas on a 131-foot steel tank in Ohio. In addition to an unobtrusive solution, the City of Steubenville required the company to mount the antennas on the side rather than the top of the tower and limited installation to between mid-December 2010 and January 2011.

T-Mobile Construction Manager Keith McCombs and Jason Hughes, field coordinator for T-Mobile's installation contractor, Speelman Electric Inc. of Tallmadge, Ohio, immediately ruled out welding: too many potential U.S. EPA conflicts over the integrity of the tank's membrane seals. It was also too-consuming: They'd have to drain the tank. Epoxy mounting was out: how durable would the bond remain given Ohio's harsh winters? Capacitor discharge welding wouldn't work, either: too time-consuming because of the number required, plus Speelman would have to come back in the spring to touch up the powder paint around the studs.

Finally, T-Mobile contacted Metal & Cable Corp. Inc. of Twinsburg, Ohio, which had developed and introduced the Magnemount Side-Tank Mount (M-STM) six years earlier.

A series of permanent magnets combined with an independently suspended mounting system, the system provides a noninvasive mount that accommodates the varying curvatures of water towers, including the side sectors. Entirely magnetic, it requires no epoxy coating or welding that can compromise a tank's protective surface coatings and bladder seals.

Available in five modifiable designs, the solution satisfied all parties' needs. T-Mobile bought 12 antenna systems consisting of six base plates on the tank's four sectors holding three antennas each; and one 90-degree, 24-square-foot center mast/base plate.

Like all Magnemounts, assembly didn't require special tools or expertise. On the ground, each base plate is mounted to a horizontal shank that attaches to the vertical mast with U-bolts that are tightened to securely hold the final antenna pipe and assembly.

After hoisting the mast and horizontal shank up the tower with bearing and rope, installers pick a desired location and place the base plate. The magnets are loosened so they can automatically orient themselves to their maximum capacity. The lock-nuts on each need only one turn with a hand wrench to secure the mount in place.

The entire process usually takes less than an hour. T-Mobile's antennas were installed in one day. Factoring in Speelman's additional civil and electrical work — cell infrastructure, coax cable feeds, magnetic supports to the mounts, etc. — the project took two weeks.

“The most important reason for using the system is speed to market,” says McCombs.

Hughes was impressed by how easy the product was to install in cold weather. “It's low-maintenance and presents no corrosive rust issues,” he says.

The manufacturer hasn't received a report of service failures or return in the six years since introducing the side-mount solution. Magnets come with lifetime warranty and the complete system for five years. Both warranties offer 100% free replacement or refund that includes freight both ways.

—David Klein (david@metal-cable.com) is president of Metal & Cable Corp. Inc., Twinsburg, Ohio.