Lightning safety is a critical issue on college and university campuses. Lightning—which may be becoming more frequent due to climate change1—can ignite fires, damage structures, and injure occupants. Powerful lightning surges, measured in tens of thousands of amperes and millions of volts, could fry electronic devices and systems that are essential to a school’s operations, academic resources, and research programs. Recent lightning incidents at academic institutions have caused fires and damage. Such incidents have occurred at Albion College, Baldwin Wallace University, Brown University, Gettysburg College, Hood College, and Stanford University. A lightning strike at Mount Holyoke College in July 2021 started a fire that closed a housing unit, displacing 140 students for at least a year while repairs were made. Strikes elsewhere have caused uncounted incidents of damage to equipment and electrical devices. Boston College is one example of an academic institution that takes lightning safety seriously. It recognizes that safety precautions are required for its multiple campuses in and around Boston, Massachusetts. According to Frank Martins, project coordination manager for Boston College’s Facilities Services, “We install lightning protection systems on all our buildings that shelter people or equipment.” The college’s commitment to protecting its assets is part of a stringent risk management strategy, which is prudent, Martins said, because the college is self-insured. 40 • IIBEC Interface July 2022 A CASE STUDY: Lightning Protection at Boston College Figure 1. Campuses need strong policies and procedures to ensure that lightning protection is considered whenever anything is to be installed on a building exterior. In this example, the lightning protection system will be extended to the top of this security camera mast. All Photos: Smokestack Lightning Inc. By Jennifer Morgan and Michael Chusid Boston College’s decision to prioritize protecting its infrastructure from lightning originated over 30 years ago when a campus-wide evaluation revealed that the college’s information technology (IT) equipment was vulnerable to lightning. The evaluation identified other areas at high risk, such as facilities housing hazardous materials (for example, laboratories), irreplaceable cultural assets (museums and libraries), venues that are difficult to evacuate (dormitories and places of assembly), and emergency and health services (campus police and infirmaries). More recently, the Boston College Eagles football team has had postseason bowl games canceled or postponed due to thunderstorms. A commitment to human safety is at the heart of the school’s current lightning protection program. Martins explained, “Today, it’s a matter of life safety. We have about 15,000 students on campus, and I don’t want anybody losing their lives. You can always put equipment back, but you can’t put people back. So that’s number one.” Martins, who began his career as an electrician and has taken advanced training in lightning protection, reviews engineering drawings and specifications for anything that is built, renovated, or installed at the college. He says, “Lightning protection is always at the forefront of my concerns.” At Boston College, design and construction contracts for new buildings and major remodeling projects are written to require that lightning protection systems are installed in accordance with national standards and certified by independent third-party agencies. Vigilance is also required for smaller projects. When one of the college buildings was connected to cable TV, Martins recalled, the vendor did not install a surge protective device on the cable entering the building. “A lightning strike outside the building entered the structure through the new cable. Once inside, the surge daisy-chained to a few other buildings. We lost a lot of equipment.” Boston College has since implemented strong policies so that “nothing goes into a building until we verify that it is protected.” (See Fig. 1.) SELECTING AND MAINTAINING A LIGHTNING PROTECTION SYSTEM Lightning is a powerful electric discharge between the atmosphere and earth. In addition to surge protection, a lightning protection system creates multiple paths that can safely conduct lightning from air terminals (informally called “lightning rods”) at the top of a structure through low-resistance conductors to grounding electrodes at the base. A lightning protection system also interconnects metallic structural elements and building systems, creating equal electrical potential throughout the structure in the event of a lightning strike. The history of lightning protection systems can be traced to Benjamin Franklin, whose research on electricity led to his invention of an early lightning protection system.2 Franklin’s techniques have been refined through two centuries of ongoing science. Today, lightning protection systems are effective and July 2022 IIBEC Interface • 41 Figure 2. The dark patina on these copper and bronze lightning protection components is the result of decades of exposure. Over time, the construction adhesive used to secure the air terminal base has deteriorated. Repairing this issue is simple if it is caught before further damage is done. Figure 4. Devlin Hall at Boston College. In the foreground of this photo, a conventional air terminal (lightning rod) is recognizable on top of a rooftop air-handling unit. The metal cross on top of Devlin Hall serves the same strike-termination purpose as an air terminal, acting as a place where lightning can attach to the structure and safely travel to ground through the lightning conductor cables secured to the face of the steeple. Maintaining the full range of lightning protection equipment, from simple air terminals to ornate strike termination devices, requires the knowledge and skills of a certified lightning protection specialist. Figure 3. A lift was required to inspect the lightning protection equipment on St. John’s Seminary at Boston College’s Brighton, Mass., campus. 42 • IIBEC Interface July 2022 FIVE TIPS FOR MAINTAINING LIGHTNING PROTECTION SYSTEMS • Train facilities personnel to identify and report wear and tear: Lightning protection equipment is made of heavy-duty, durable materials that can remain serviceable for the life of a building. However, weather and mistreatment can take a toll, especially on adhesives, fasteners, and joints. Facility maintenance personnel should be trained to spot damage such as the dislodged and poorly fastened conductor shown in Fig. 5 and report it so it can be promptly repaired. • Protect rooftop lightning protection equipment: Air terminals and conductor cables are frequently required on top of rooftop mechanical units that rise above lightning-protected zones. The lightning protection equipment can be damaged during maintenance of the mechanical units if it is not handled carefully (Fig. 6). • Ensure correct bends in lightning protection conductors: Bends in lightning protection conductors must have a radius equal to or greater than 8 in. (200 mm) to reduce the potential for lightning to arc from the conductor into other building components. Figure 7 shows a bend problem. • Prevent at-grade problems: Figure 8 shows a down conductor cable that is kinked and frayed, probably due to rough treatment during groundskeeping. To prevent this type of damage and deter theft, cables near ground level can be enclosed in a protective conduit. In new construction, down conductors are typically installed in the building interior to provide even Figure 5. In this photo, the fasteners that should connect the cable to the air terminal bracket and hold the cable to the coping are no longer in place. Figure 6. When the hood was removed from this exhaust equipment, the lightning protection system’s conductor cable became frayed and the air terminal was misplaced. greater protection and better appearance. • Include lightning system experts on reroofing project teams: Figure 9 illustrates haphazard treatment of lightning protection cables by roofing contractors during reroofing. To prevent this type of problem, Boston College requires roofing contractors to subcontract with the college’s preferred lightning protection firm. The lightning protection specialist carefully removes components, marks the locations of throughroof penetrations that might otherwise be concealed by the new roof, and then installs new or reconditioned lightning protection components to meet national standards. Figure 9. During reroofing projects, there is a risk for damage to cables and other components of lightning protection systems. Collaboration with contractors with lightning protection systems expertise can help minimize this risk. Figure 8. Example of a kinked and frayed down conductor cable. The damage may have occurred during groundskeeping. Note that the clamp connecting the cable to the ground rod is not of sufficient size to safely conduct a powerful surge of lightning; a lightning protection professional will be able to identify and remedy such defects. Figure 7. Copper bar used to create a common point to interconnect the structure’s several grounding systems. While the bends in the small-diameter cables and wires are acceptable, the bend in the large, braided conductor cable was either installed incorrectly or damaged when additional services were attached to the bar. affordable, and nationally recognized standards for them include the National Fire Protection Association’s ANSI-accredited standard, NFPA 780, Standard for Installation of Lightning Protection Systems.3 Around 2005, Boston College tried a nonstandard approach to lightning protection known as “early streamer emission” systems (among other names) on several buildings. The promoters of these systems relied on a discredited standard to claim their proprietary equipment would protect large areas against lightning strikes and reduce construction costs.4 However, Martins said, “When we found out that they don’t do what they’re supposed to, we took out them out and put in standard lightning protection systems.” The components of the college’s current lightning protection system are fabricated from high-grade copper, bronze, and aluminum that can last the life of a building. Yet, Martins cautioned, weather and mistreatment can take a toll on these systems (see Fig. 2). To ensure optimum performance of its lightning protection systems, Boston College has engaged a contractor to annually survey the systems on its more than 160 buildings and make necessary repairs. Bill Simpson, the contractor’s president, said the lightning protection projects at Boston College are challenging because “each of their buildings is unique, and most have gone through many generations of remodeling.” (See Fig. 3 and 4.) After surveying the buildings, he and Martins establish priorities for repairs and upgrades that, yearby- year, are bringing the school’s buildings up to standards. Martins said the service contract is awarded based on competitive bidding and is very affordable. Doing maintenance and repairs on an ongoing basis “saves us a lot in the long run,” he said. “Having safety programs in place is protection against lots of headaches.” REFERENCES 1. Chao-Fong, L. 2022. “‘Drastic’ Rise in High Arctic Lightning Has Scientists Worried.” The Guardian. January 7, 2022. https://www.theguardian .com/environment/2022/jan/07/ l i g ht n i n g – h i g h – a r c t i c – r i s e – scientists-worried. 2. The Franklin Institute. n.d. “Benjamin Franklin’s Inventions.” https://www.fi.edu/benjamin-franklin/ inventions. 3. National Fire Protection Association (NFPA). 2023. Standard for Installation of Lightning Protection Systems. NFPA 780. Quincy, MA: NFPA. 4. Uman, M. A., and V.A. Rakov. 2002. “A Critical Review of Nonconventional Approaches to Lightning Protection.” Bulletin of the American Meteorological Society 83(12): 1809–1820. https://doi.org/10.1175/BAMS-83-12- 1809. Please address reader comments to chamaker@ iibec.org, including “Letter to Editor” in the subject line, or IIBEC, IIBEC Interface Journal, 434 Fayetteville St., Suite 2400, Raleigh, NC.27601. July 2022 IIBEC Interface • 43 Michael Chusid was an architect and a fellow of the Construction Specifications Institute. Sadly, Chusid passed away in May of 2022, prior to publication of this article. His contributions to the betterment of building design and construction over many years were significant, and he will be greatly missed. Michael Chusid Jennifer Morgan is co-owner of East Coast Lightning Equipment Inc. and education coordinator of the Lightning Safety Alliance. Jennifer Morgan S P E C I A L I N T E R E S T FBC Funds Building Design Study The Florida Building Commission (FBC), in conjunction with the University of Florida and Cornell University, has studied the impact of wind and wind-driven rain. Titled “Development of Wind-Driven Rain Climatology and Coincidental Wind Speed Return Period Maps for Florida and Surrounding Coastal Areas,” the research project is scheduled to conclude ahead of a final report due last month. “For decades, rainfall amounts have been recorded at hourly intervals,” wrote Kathy Krafka Harkema, APR, on the Fenestration & Glazing Industry Alliance blog. “The hourly data provides a snapshot in time. Conditions can vary significantly in storms over the course of an hour. “Peak wind speeds have been clocked for years as well, but little data have been compiled to analyze the one-two punch and true impact of wind and rain together in real-life weather conditions, like hurricanes, tropical storms or thunderstorms. “As part of the study, more precise one-minute wind/precipitation data has been obtained for 243 weather stations in Florida and other coastal areas and in nearby states in the Southeastern U.S. Researchers are comparing one-minute data with hourly data from the same sites to compare and contrast differences.” Source: fgiaonline.org Photo by Blake Connally on Unsplash
