Knox County once had the tallest tower anywhere in the world | Know Your Knox
Sixty years ago, Knox County was home to the tallest structure in the entire world.
The story of the WIMZ-FM tower, built by WBIR-TV in 1963, includes competition, miscalculations and a missed chance to make it into the most famous book of world records.
The tower still stands just off Rutledge Pike in Corryton at a staggering 1,752 feet tall, or 534 meters. That's about 300 feet taller than the tip of the Empire State Building and almost as tall as two Titanic ocean liners standing on end.
While four giant TV and radio masts look down on Knoxville from Sharp's Ridge north of downtown, the older and taller WIMZ tower sits 15 miles northeast of the city on the border of Grainger County near House Mountain.
It does not sit on a ridge and is not easily visible from Knoxville, but comes into striking view on Rutledge Pike. At least, it's striking if you know what you're looking at. To the uninformed eye, it appears like most other towers in the area, a giant needle held up by guy wires.
When the Knoxville News Sentinel publicized plans for the tower on March 19, 1963, WBIR's manager John P. Hart said the mast would enable 1.5 million people to receive the station, bringing them local favorites like Cas Walker and national network hits like "The Andy Griffith Show" and "The Twilight Zone." The tower also would provide TV to 50,000 Kentuckians for the very first time.
When WBIR finished the tower in August 1963, the Knoxville News Sentinel hailed it as a "cloud-piercer" that would improve coverage across several states. Less than one month after the tower began transmitting in October 1963, it was surpassed in height by the 2,063-foot KVLY-TV mast in North Dakota, which held the record for decades.
For multiple reasons, including a misjudgment about how the city would grow, WBIR sold the tower to the parent company of 103.5 Classic Rock WIMZ-FM in the late '70s and returned to Sharp's Ridge. The station built a 1,504-foot tower from which it still transmits.
Why was the 'cloud-piercer' tower built so tall?
In the days before cable and streaming, TV viewers relied on radio waves transmitted from towers and received by antenna. If a building or mountain stood between a home and the signal, viewers would get poor reception, or no reception at all.
Kevin Duplantis, director of engineering at Midwest Communications, the company that owns WIMZ, said towers "need to be high and look down to minimize the effects of the hills and ridges," especially for TV signals, which are generally harder to pick up than FM radio.
In the world of broadcast, height is measured in what's called height above average terrain, which shows how tall a mast stands above the surrounding area. If a tower is on a ridge, the height of the ridge is added to the height of the tower. That means the 1,752-foot WIMZ tower on relatively flat land has around the same height above average terrain as a 1,500-foot tower on Sharp's Ridge.
WBIR wanted tower on House Mountain, but WATE foiled plans
It is a clear structural advantage to build a transmitting tower on a ridge or mountain. When WBIR set out to build a tower in East Knox County, it set its sights on House Mountain, which rises about 1,020 feet above the surrounding terrain and is the highest point in the county.
The 1960s were a time of rapid growth and competition for TV stations, both nationally and in Knoxville. In the case of House Mountain, WATE-TV had a distinct advantage.
"We happen to own the top of House Mountain," said Bob Williams, a retired chief engineer at WATE, with a gleeful chuckle. "Therefore, we're not about to sell it to Channel 10."
Indeed, WATE still owns a small plot of land on top of the mountain, a station spokesperson told Knox News, though 500 of the mountain's 527 acres are state-owned land in the House Mountain State Natural Area.
Williams was hired at WATE in 1959, and spent more than 50 years with the station. He said the land on House Mountain was purchased by Stuart Adcock, who founded WROL-TV, Knoxville's first TV station, which would later become WATE. Adcock wanted to build an FM radio tower on the mountain, but it was never constructed. WATE did not purchase the land specifically to thwart WBIR's plans, but still kept its competitor off the peak.
So WBIR built a tower that rose 700 feet higher than House Mountain. But it wasn't all smooth sailing and soon, the station would leave their record-holder and return to Sharp's Ridge.
WBIR thought Knoxville would expand east, but it went west
WBIR encountered some problems early on with its shiny new tower.
By December 1963, enough Knoxville customers had complained of bad reception that the Knoxville News Sentinel published a story advising residents to adjust their antennas to the northeast to pick up a better signal.
At the time, the station's general manager John Hart said 82% of customers were getting better reception and another 15% were receiving a signal for the first time.
But all the antenna bending in the world couldn't make up for the station's broader miscalculation. Williams said stations assumed in the early 1960s that Knoxville would expand into the eastern part of the county. The opposite happened. Throughout the 1960s and '70s, the city marched westward. West Town Mall opened in 1972 and the town of Farragut was incorporated in 1980.
That meant more TV and radio customers were moving farther away from the tower in Corryton, which had long since lost its claim to global fame. By 1979, the station's general manager Neal Branch said WBIR would leave the tower and return to Sharp's Ridge to improve coverage to the city and surrounding areas.
The station completed a new 1,504-foot tower, the original colossal mast on Sharp's Ridge, in 1980. It stands next to WBIR's first tower, which is being dismantled. The station did not respond to requests for comment.
WIMZ tower did not appear in Guinness Book of World Records
Even though it broke the world record, the WIMZ tower did not break into the most famous records book.
The 1964 Guinness Book of World Records listed the 1,749-foot WRBL-WTVM tower near Columbus, Georgia, completed in May 1962, as the tallest structure in the world. The WIMZ tower, just three feet taller, broke the record a little over a year later, but not soon enough to make the book.
The 1964 book mentioned a contract for an upcoming tower unlike anything the world had seen.
In the rural plains of North Dakota in a tiny town called Blanchard, KTHI-TV built a 2,063-foot tower in only 30 days, between Oct. 2 and Nov. 1, 1963, according to the 1965 Guinness Book of World Records. That tower, now operated by KVLY-TV, was the tallest structure in the world from 1963 to 1974, and again from 1991 to 2008.
Between its construction in 1974 and catastrophic collapse in 1991, the Warsaw radio mast in Poland was the tallest structure in the world at 2,120 feet.
In 2008, the Burj Khalifa, still the tallest structure in the world at 2,717 feet, surpassed the KVLY-TV mast. The North Dakota mast remained the tallest structure in the Western Hemisphere until a portion of its antenna was removed in 2019. It now stands at 1,987 feet. The 2,060-foot nearby KRDK-TV mast in Galesburg, North Dakota, took its place.
The WIMZ tower is taller than all but seven buildings in the world, which by definition must have a roof and walls. It is narrowly eclipsed by One World Trade Center in New York City, the tallest building in the Western Hemisphere, whose antenna reaches a patriotic height of 1,776 feet.
How tall are Knoxville's TV and radio towers?
The WIMZ tower is the tallest tower in Knox County, but that doesn't mean it stands the tallest. That's because the massive three-pronged WVLT-TV tower, which rises over the confluence of I-275 and I-640, reaches a taller height from atop Sharp's Ridge. A stunning 4k aerial video posted to Facebook shows the view from the top of the tower.
The WBIR and WATE towers are a similar height and stand side by side on a central portion of the ridge.
Here's how Knox County's tallest towers stack up, ranked by their height above average terrain, which combines tower height with elevation above surrounding areas. All data on tower height was sourced from FCCInfo.com, a service of engineering consultancy firm Cavell, Mertz and Associates that tracks data on TV and radio towers.
1. The WVLT-TV tower is 1,809 feet above average terrain, while the tower itself is 1,534 feet tall. It sits on a portion of Sharp's Ridge that is 275 feet tall. It stands taller above downtown Knoxville than One World Trade Center in New York City.
2. The WBIR-TV tower is 1,791 feet above average terrain, while the tower itself is 1,504 feet. It sits on a portion of Sharp's Ridge that is 287 feet tall.
3. The WIMZ-FM tower is 1,752 feet tall. It sits on relatively flat land in East Knox County, and was briefly the world's tallest structure in 1963.
4. The WATE-TV tower is 1,736 feet above average terrain, while the tower itself is 1,446 feet. It sits on a portion of Sharp's Ridge that is 290 feet tall.
5. The WJXB-FM tower is 1,329 feet above average terrain, while the tower itself is 1,089 feet. It sits on a portion of Sharp's Ridge that is 240 feet tall. It has red and white stripes, like a spindly candy cane. The local office of Midwest Communications, which owns WIMZ-FM, sits at its base.
Know Your Knox answers your burning questions about life in Knoxville. Want your question answered? Email knowyourknox@knoxnews.com.
Daniel Dassow is a reporting intern focusing on trending and business news. Phone 423-637-0878. Email daniel.dassow@knoxnews.com.
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This article originally appeared on Knoxville News Sentinel: Knox County was once home to world's tallest tower
