Radio World asked several contributors to attend various sessions at the NAB2003 convention this spring. Here, Jeff Johnson summarizes presentations at “Facilities Management for Radio and Television,” chaired by Troy Pennington of Cumulus Broadcasting, Mobile, Ala., and presented by a range of industry professionals concerned with the safe, efficient and legal management of broadcast property. It was part of the Broadcast Engineering Conference.
“New Standards for Broadcast Structures ANSI/TIA/EIA-222-G” – Discussing the next revision of structural standards for steel antenna towers and antenna supporting structures were David Brinker, PE, Rohn Industries Inc.; John Wahba, Ph.D., PE, Radian Communication Services; and Mark Malouf, PE, Malouf Engineering International.
(click thumbnail)The NSP RF protective suit provides protection in fields up to 1,000 percent of the FCC’s MPE exposure limits. It is shown without the hood in this image from Richard Strickland’s presentation.
The most comprehensive change to the standard since its first publication in 1949 will take place with the release of TIA/EIA-222-G later this year. It incorporates a performance-based approach called “limit states design” to ensure that structures are safe under extreme loading conditions. By comparison, the old standard, which uses a “serviceability limit states” approach, checks only that the structure is capable of the service under normal conditions, according to a white paper published with the presentation.
“The changes are being made not because of structure failures, but to be compatible with contemporary building codes,” said Brinker.
Three structure categories will be introduced according to reliability requirements. Category I structures present a low hazard to human life and are used for optional or non-critical services. Category II structures represent a substantial hazard to human life and are used for services that may be provided by other means. Category III structures are used for essential facilities and represent substantial hazard to human life upon failure.
More sophisticated modern understanding of wind loads, ice loads, seismic loads and foundation parameters generally will allow more capacity on existing structures under the new standard, although not in every case. Wind loads will take into account the immediate environment of a structure, such as urban or hilly, flat open or hurricane shoreline. A three-second gust wind speed is the basis of the new criteria replacing fastest-mile. Ice loads will be escalated with height, and seismic loads will be by geographic area. All three loadings will be determined by specific local county criteria from wind, ice, and seismic maps.
222-G eliminates the term “normal soil.” It is replaced by “presumptive” soil parameters for sandy and clay soils. Presumptive parameters are not allowed for Category III structures. In addition to hot dip galvanizing, cathodic control or concrete encasement will be required for guy anchors in corrosive soil.
It was stated that existing towers do not need structural review unless a change is made. Removing a load from a tower also constitutes a change, and no towers will remain “grandfathered.”
“Designing for the Unexpected” – George W. Crowe, former head of radio engineering at the BBC and later of the internal property (real estate) team there, asked “What have we learned in 80 years; are we still making the same mistakes? And are we really taking notice of the lessons learned?”
Crowe answered by stating, “Do not design to prescription” and “justify the cost of the unexpected in early planning.” It is important to design resilient facilities adaptable to changes in technology, programming and organization. Work with architects from the beginning to expect change and flexibility in usage throughout the life of a structure. An example given was locating primary services along defined zones to eliminate the necessity of relocating them later.
Resiliency also is important in backup facilities and disaster recovery plans. An “N+1” approach, meaning a greater number of smaller units and more of them than necessary, should be planned. Be prepared to use alternate studios, revised interconnectivity and backup power. Review and be certain to test procedures to be implemented when the unexpected occurs.
“Telecommunications Towers and Equipment: Legal Duties of Owners, Engineers, and Contractors” – “What do you do when you receive that chilling call that your tower is on the ground?” asked attorney Vincent F. O’Flaherty of Niewald, Waldeck and Brown.
Referring to “tall towers” as those exceeding 1,000 feet, O’Flaherty handles litigation resulting from the unexpected event of a tower collapse.
“Tower loss occurs more often than you think. It may occur due to weather related causes, such as ice loading, human error of those working on towers or simply age,” said O’Flaherty. “However, too many of the reasons for tower failures and how they fall are hidden in lawsuits and insurance claims and are not publicly available.”
The legal terms “cause” and “origin” will be used by the involved parties to determine why a tower fell. It is critical, as broadcasters, to get your own team – insurers, engineers, attorneys – on site as quickly as possible, he said. Secure the site immediately. Many parties, including government agencies, contractors and tenants, will be involved. Cooperate with these fully, but concentrate on your own investigation.
The next area of concern is the immediate return to air and the rebuild process.
“Any delay – financial, or engineering – may result in long-term legal ramifications if income has been lost,” said O’Flaherty. “Insurance and business interruption programs should be specifically designed for your tower.”
Consider replacement costs under new regulations, extensiveness and adequacy of coverage, liability for workers on towers, adequacy of tenant’s and contractor’s insurance, and the possibility of damage to neighboring property.
“Collapse of a 2,000-foot tower is a major news event,” said O’Flaherty. It will attract attention. Damage control and investigation are under your control if you are the first on the scene, contact your insurer immediately and secure evidence that will be necessary later. Make certain nothing leaves the site. Photograph and document the damage within a two- to three-day window.
“Initial damage control is very critical to your defense in the matter,” said O’Flaherty.
“RF Hazard Control Equipment” – With the FCC ramping up enforcement of RF safety regulations and using large fines to encourage enforcement, Richard R. Strickland of RF Safety Solutions LLC gave a timely presentation.
With responsibilities and liabilities being dictated by regulations, Strickland said that hazard control equipment is part of the solution. Regardless of the licensee’s transmission location – whether owned, rented, or shared – it is the licensee’s responsibility to employees, visitors and contractors for RF safety. FCC regulations must be followed to protect all three of these, and OSHA regulations must be followed for employees.
“If operating under an RF safety program, you actually have fewer restrictions,” said Strickland. “Without a program, you do not have a controlled environment.”
RF hazard control equipment often is a component of such a program. The human body is most susceptible to RF exposure at VHF frequencies. “Note that the average ungrounded adult male makes a great Channel 6 antenna and a possibly shorter female an FM antenna,” said Strickland.
Discussing workers on site, Strickland emphasized that they must be “fully aware” and be able to “exercise administrative and engineering controls” of their exposure to RF fields. Access shall be limited only to such workers. Administrative controls are time averaging, RF personal monitoring and RF protective clothing.
An example of an engineering control is a purely mechanical protection device, such as an interlock. “Fully aware” workers have received both written and verbal information and training in RF exposure control.
Strickland, discussing RF personal monitoring devices, stressed the importance of a “shaped” frequency response, being more sensitive in the VHF range, to alert accurately relative to the stricter standards in that range. The monitor, looking like a portable radio, which in a sense it is, should be worn outside any garment, on the torso, facing forward. The most sensitive parts of a body are the eyes, and for males the testes. Be certain the device is loud enough or bright enough to be noticed in the event of an alert.
Protective suits must be worn properly. Particular attention must be paid to electrical contact between the socks worn and the suit, or no protection will be afforded. Hoods should be worn above 800 MHz to protect the eyes. Consider suit protection to be no better than 10 dB. Wear the monitor outside the suit for the sensor to work properly.
“Success Factors in the Planning of, Design, Construction and Integration of a High-Technology Digital Facility” was presented in part by Edward Hobson, editorial vice president and fellow of SMPTE. Hobson is responsible for technology issues related to new media systems and their application. Also presenting was John Aalto, senior vice president of National TeleConsultants Inc., Engineering and Consultants Group, responsible for client A+E and strategic planning.
When designing such a facility, consider three areas of strategic importance: business issues, workflow and technology, they stated.
“What is your key business? Creating content, delivering content, delivering eyeballs, transmitting content, or a combination?” asked Hobson. “Maintain focus on your core business in planning a new facility.”
Perform a survey of present and near-horizon technologies and long-term changes. For example, videotape-based technology requires different workflow implementation than server-based technology.
Do not mimic workflow topologies suitable for one technology in another. For example, video servers allow for one version of an item to appear in one place only: the server. Plan to ingest, edit, review, air and archive material without creating multiple copies. The item remains on the server at all times and eliminates non-value-added work and multiple versions that may be confused.
Your newly designed facility should be considered a “container” to support your product’s creation.
“Vital to successfully implementing large media technology projects requires experience, planning, superior project management and execution,” Aalto said. The space planning and architectural support phase of a media technology facility requires more-detailed and future-focused needs planning. A “technical core” must be planned in addition to the building core. A planning goal should be stacking of technical rooms on each floor with one wall common that could be a raceway and accommodate changes that will occur.
Space planning should begin by focusing on a “wish list,” then trimming judiciously to meet a budget. An example given was taking a couple of feet off of a large studio, which would probably not be missed, rather than eliminating small craft studios.
Tape storage may require more space than servers. However, will tape be around in 10 years? Transition to server technology will save space, but will increase cooling load.
“Design of media technology should take place as late as possible in the timeline to take advantage of the latest technology,” said Aalto. “Open systems technology from different manufacturers allows for making changes, expansions and additions without being tethered to the constrictions of a single manufacturer.”
In summation, Aalto outlined three success factors for projects: design from the general to the specific; structure and document the process; and obtain approval by principal people at key points throughout the process.
