Published: TV Technology magazine Issue: May 22, 1997 Lots of Orders for DTV Towers, But Not Enough Crews Written by - Joe Fedele Now that DTV appears to be a reality, many broadcasters are moving beyond the speculative stages and seriously analyzing its inception. The first step in implementing any digital TV service begins at the antenna and tower, but industry studies are showing that it could take longer than the required five years because there simply aren't enough qualified crews to actually get the job done. Last month network broadcasters agreed to provide DTV coverage to 43 percent of all households within the next two years. While this might seem to many as an awe-inspiring commitment, the primary objective is to have only one full-powered TV signal in several of the major markets and not 43 percent of all TV stations up and running. This important distinction simplifies the process of meeting broadcasters' short-term commitment in the first and second years of the plan. The coverage model for the first two years of the transition plan is not expected to be a problem, as many of the larger network-owned VHF stations have stepped up to the plate and offered to build DTV stations. But many broadcasters face the very real possibility of having to upgrade, or even replace, their existing towers in order to provide DTV service. This may very well prove to be a more formidable task than it appears on the surface. Yet, the biggest problem most broadcasters will likely face is the availability of tower erection crews specialized in building "tall towers" (a structure that exceeds roughly 1,000 feet in height). Some in the industry have estimated that although tower companies can install about four towers per month, meeting the FCC mandate to get all commercial stations on air by the year 2003 would necessitate installing at least one DTV antenna every two days. There are two basic types of towers, self-supported and guyed. Self-supported tower heights are restricted to about 700 feet in height while guyed structures reach upwards of 2,000 feet or better. Working on tall towers is a more specialized trade when compared to short towers. Tower installers differentiate between tall and short towers in a number of ways and are quick to point out when they have the manpower and equipment necessary to work on tall towers. Art Allison, senior engineer for the NAB, studied the availability of tower crews and found only nine companies and 21 crews available nationwide that were both qualified and equipped to work on towers exceeding 1,000 feet in height. But of those, only about eight crews actually specialize in work on towers exceeding 1,200 feet. The availability of crews capable of working on short towers (less than 1,000 feet) broadened to about 40. This availability of tall tower crews becomes a critical factor in DTV implementation because approximately 40 percent of the 1,551 full-powered TV stations in the country utilize towers exceeding 1,000 feet in height to support their antennas. While 43 percent of stations use towers ranging from 300 to 1,000 feet. The NAB estimates that there are a total of about 1,400 towers currently in use today. The connection between tall towers and the availability of qualified work crews becomes a problem in the third and fourth years of the proposed DTV plan. "Seventy-percent of all tall towers will require either strengthening or replacement," Allison said. And, there are some in the industry, he admits, that estimate this figure to be as high as 90 percent. Because the lion's share of all TV stations fall into the thrid and fourth years of the transition period, some in the industry fear that many broadcasters will not be able to meet their goal of providing DTV service in their anticipated time frame. Broadcasters with the foresight to begin this implementation now may very well outpace their competition in meeting their goals. To further complicate the matter, there are only four major tower manufacturers currently in the business of installing tall towers, Doty Moore Tower Services (Cedar Hill, Texas), Klein Towers (Columbia, S.C.), LeBlanc & Royal Telecom (Oakville, Ontario Canada) and Stainless, Inc. (North Wales, Pa. ). There is some speculation in the industry, however, that some of the small tower fabricators may introduce new lines of tall towers if demand makes this cost effective for them. Tom Vaughan, a broadcast engineering consultant and the former owner of Micro Communications Inc , points out the fact that stations have to move quickly. "It takes about six months to manufacture some tall towers and another four months to install them," he said. "If you do the math and take into account the number of available tower crews, the time to fabricate the tower, and then factor in the install time, you appear to have a problem (in meeting some of the timelines)." The potential mad rush to implementation bodes well for tower manufacturers, who stand to profit considerably. Since a digital television standard was adopted by the FCC at the end of last year, Peter A. Starke, vice president of sales for Stainless, has seen a marked increase in the number of broadcasters that are actively investigating tower improvements or replacements. "Normally Stainless performs about 50 structural analysis per year on towers," he relates. "As of the end of March, we have already done about 30." While some towers may need to be replaced, others require only an upgrading of the tower guys, diagonal members, bolts and support steel, in order to withstand the extra load imposed by yet another TV antenna. From a technical standpoint this may be accomplished. But then you may have problems with insurance companies that are unwilling to provide coverage for a tower that has been modified. Another problem that may arise is that many of the towers in use today were built at a time when less stringent engineering standards were in place. Again, insurance companies may be reluctant to work with you if your tower was not fabricated to meet the newer RS222E EIA standards. Insurance companies are reluctant to cover towers that have had their supporting members reinforced because this generally includes welding additional steel to the existing tower legs. "The process of welding is not like gluing two pieces of metal together," Vaughan said. "What you're doing when you melt the metal is actually crystallizing it and changing [its] original dynamic capabilities." Another limiting factor in tower reinforcement is the ability of the tower base plate to carry the added load. This, and the ability of the surrounding soil's ability to support the added weight, often makes tower reinforcement impractical. Broadcasters should expect to pay between $700,000 and $1.1 million dollars for a typical 1,000 foot tower, while 2,000 footers range from $2.4 million to as high as $4 million. Self- supported towers reaching about 700 feet in height will run about $1.75 million. This wide range in pricing will depend on such things as the maximum capacity of the tower and the wind loading requirements. Broadcasters wishing to lease out tower space to communications companies, or for microwave transmissions, will pay a premium for the privilege. Towers located in coastal regions (such as Florida) will need to withstand hurricane force winds. To make matters worse, broadcasters must also compete for the availability of towers and technical resources with other industries such as PCS, Wireless Cable and other growing telecommunications companies. The general consensus at the NAB convention was that a smooth implementation was possible, but not until considerable resources were committed to DTV. With the allotment table now set, that money (and technology) will have to be found. It's money small-market stations may not have.