Explore the practical, functional, flexible world of manufactured outdoor buildings.
When you need a transmitter building that requires minimal site preparation and provides a lifetime of service and protection with maximum security, durability, quick delivery and set up, then a prefabricated shelter may be your best investment. A shelter can be designed to a customer''s specifications for a turnkey installation. The unit will be shipped fully assembled, ready to go, with only utility and ground connections required assuming there has been advance preparation of an acceptable foundation with ample large vehicle site access. A prefabricated shelter can include lighting, electrical wiring and receptacles, heaters, air conditioning and ventilation, standby electrical power generators with automatic transfer panels, cable ladders, and other systems such as fire suppression, master grounding, and high-tech security. I have three prefabricated buildings in our five-station network ranging in size from 10'' x 12'' to 24'' x 30''. Each one is quite suitable.
Depending on the manufacturer, some buildings come as a complete unit ready to set in place while others can be delivered in sections and quickly assembled at locations having narrow or otherwise limited access. A minimal crew can typically assemble a sectionalized structure in less than a day. Fully constructed buildings are most often constructed of fiberglass aggregate exteriors that sit on a metal skid system requiring a prepared concrete foundation. Pre-cast concrete buildings are usually delivered as wall, roof, and floor sections that are easily and quickly assembled on site. Buildings of that type frequently require a level foundation of sand or gravel on a pre-approved site. Many building manufacturers offer a wide variety of exterior finish types and colors to match or otherwise blend the structure''s appearance with the surrounding environment and existing structures. The most common exterior finish is aggregate stone, but I have seen designs that also offer brick, cedar and other finishes.
Once delivered on-site, the building is hoisted into position on the foundation slab.
In addition to their nice appearance, many building types can also be bullet resistant (specify UL 752 – Level 4 bullet resistant). Prefabricated shelters greatly minimize or eliminate the potential for rust, warping, corrosion and burning with typical fire ratings of 1.5 to 2 hours. For coastal area operations, these types of shelters are constructed to be water and air tight, and to withstand extended periods of humidity, rain, and hurricane force winds. Some manufacturers also provide seismic rated units for use in earthquake prone areas.
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There is no such thing as a one-size-fits-all cookie-cutter design. Your building criteria should be based on purpose, function, equipment placement and required customization. All leading prefabricated shelter companies have an in-house staff that will work with the customer to ascertain their needs and design a building that best meets those requirements – both now and far into the future. Many companies also offer a high-level of integration assistance where needed by a customer who may otherwise have limited staff or other qualified external services available. In some cases, new broadcast equipment can be delivered directly to a structure manufacturer who will place the equipment within the building including electrical and HVAC systems connectivity. The building is assembled and completely wired to the customer''s exact specifications within a well-controlled environment at the manufacturer''s facility. When the building arrives on site, the station can be placed on the air quickly with minimal effort. That methodology is highly desirable for organizations seeking a turnkey installation.
Once set in place, the building is secured to the foundation pad.
When planning a building, it is important to coordinate requirements with well-qualified designers, architects, engineers, technicians, contractors, and, of course, the station''s owner. Build a team who will guarantee the best possible end result. Closely integrate the local design team with the prefabrication-building vendor''s team of in-house experts.
What to look for
Determine the design criteria of the building by calculating several parameters up front. Consider equipment sizes and placements, weights, BTU outputs, ventilation, cooling and heating requirements, and electrical power needs. Specify what RF cables will be entering and exiting the building and where. Note required cable ladders and the need for a cable entry port. Work with the building''s design team to create a master ground system within the building (halo type or other as determined) and be sure the building''s master ground system is properly connected to the tower ground system. Include EMI and RFI shielding if required. Specify an electrical surge suppressor unit for the building that will protect the entire internal electrical distribution system. When a standby electrical power generator is to be placed, specify the placement of its automatic transfer switch (ATS) within the building. Many building manufacturers can provide a structure that will include a separate room for housing the generator within projects that have a sufficient budget for such. Be sure to include the necessary surge suppression systems for all incoming and outgoing RF lines, communications and data lines, etc. For customers located in heavy snow and ice climates, roof weight bearing load should become a design criteria along with roof protection from falling ice formed on adjacently located towers. Also include protection over externally located emergency standby power generators and other critical equipment located in a similar manner.
To further protect the new facility, specify a highly functional and reliable security system that will monitor and/or detect the following parameters: intrusion, high and low temperature, humidity, air conditioning compressor lockout, smoke, fire, tower intrusion, building external entry port ground system tampering (copper theft is an issue), moisture and power failure.
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Prefab shelters can be ordered with coax entry panels already installed.
Other considerations for a prefabricated shelter project are site location and access, soil condition, and building foundation preparation requirements and limitations including a hazardous materials EPA study if required, state and local building and zoning codes, laws, rules, regulations, ownership rights, access road right of way legal clearance and utility availabilities. Can a large truck and a crane, if needed, drive into the building location? Can the owners of those vehicles obtain the necessary wide-load permits for driving on the roads leading up to the site? What about other items such as creature comforts (bathroom facilities or toilet rental), potential noise issues and the possible need for noise abatement, neighborhood light pollution from your outdoor security lighting system, drainage (is the site in a flood zone?), landscape needs and maintenance, access road maintenance including snow removal, security fencing including a gate at the access road entry point, and legal agreements with co-tenants, if any.
List the acquisition of the correct size, type, and number of fire extinguishers for the building and a well-equipped first aid center including an emergency eye wash station. Also include within the project''s budget all the necessary exterior and interior signs such as no trespassing, danger high voltage, emergency contact information, tower registration number and all required RF level notification signs.
HVAC can be built into the shelter.
Green solutions that include intelligent energy management make prefabricated structures even more attractive in today''s environmentally conscious society. Total project cost for a prefabricated shelter in most cases will be much less than comparable site-built construction. Many units are available with GSA code registration and are approved by the building department of most states therefore minimizing the time required to obtain approvals from local building and zoning departments.
Prefabricated shelters are highly practical, functional, and offer a flexible, long term, cost effective solution to many building requirements.
Thermo Bond Buildings
Bartlebaugh is director of broadcast engineering for the WKSU Stations, Kent State University, Kent, OH.