Railroads rely on lightning protection equipment to protect increasingly sensitive wayside electronics

— by Angela Cotey, Associate Editor

Railroad officials know all too well the havoc that Mother Nature can wreak on their systems. Floods, hurricanes, blizzards and tornadoes cause damage to rail infrastructure that is costly and time consuming to repair.

Lightning strikes can do a number on wayside assets, too. And these days, railroads are using more microprocessor-based equipment that’s more sensitive to lightning strikes — and more expensive to replace.

“The old relay systems could take a pretty good hit without any big issues,” says Tom Ulrich, president and chief executive officer of Arthur N. Ulrich Co.

Not so for today’s microprocessor-based equipment, which isn’t nearly as surge resistant. That’s why some rail suppliers are taking steps to make their wayside equipment more robust so it’s better able to sustain a hit. Meanwhile, companies that offer lightning protection equipment have taken steps to create systems that are as sophisticated as the equipment they’re defending. Because once lightning strikes, the difference between a poorly protected and well-protected system can mean the difference between trains continuing to operate or being stopped due to equipment failure.

“Wayside equipment has become more mission-critical to railroads as they employ more electronic equipment,” says Rob Eberly, worldwide manager for transit for lightning protection equipment supplier ERICO International Corp. “And, railroads are looking for more electronically sustainable locations in relationship to classification yards, bridges, communication sites and, now, positive train control.”

To address railroads’ lightning protection needs, ERICO offers a range of products, including air terminals or strike termination devices that can be placed on the roof of a facility to serve as lightning attachment points; a variety of down conductors that divert lightning energy into the ground; and various grounding equipment that disperses the energy into the ground so it bypasses the equipment that is being protected, says Andy Weisel, director of sales for ERICO’s railway products.

Those components — specifically, the ERITECH^® DYNASPHERE Air Terminal, ERITECH^® ERICORE Downconductor and ERITECH^® Interceptor — make up the System 3000, which can be used for applications such as communication towers, television stations, oil/gas platforms and high-rise buildings. Railroads often use the System 3000 to protect classification yards, says Eberly.

“Switch machines, retarders and other assets all need to be protected from lightning, so they put in function-specific towers to create this umbrella of protection over a given area,” he says. “You can’t cover the entire yard, but you want to cover those critical assets as they sit there on the ground from a direct strike.”

The System 3000 is installed at several railroad bridges in North America, as well.

“Bridge operations have gone to remote control, so the degree of automation has increased and therefore the susceptibility for damages has increased, as well,” says Eberly.

ERICO can tailor its lightning protection solutions to meet the needs of a specific railroad or location, based on cost and the damage risk they’re willing to endure, says Weisel, adding that while no lightning protection system is 100 percent effective, ERICO offers options that are 97 percent, 91 percent and 84 percent effective.

“We also have several sites that were problematic on several railroads in North America — wayside locations that routinely suffered lightning damage — and we adapted the System 3000 for those facilities as well as a control point,” says Eberly. “We do that in places especially where there is shared freight and passenger traffic. You don’t want downtime with the sheer frequency of trains in areas like that.”

ERICO recently introduced Electronic Track Signal Protection, a surge-protection device for signal circuits. It’s available in a 50- and 170-volt version.

But ERICO officials stress that lightning protection equipment works best when the various components work together.

“You need to look at these things as a total facility. You can spend a lot of money on surge protection, but if it’s not grounded properly, it won’t work,” says Weisel.

The implications of PTC

Protection Technology Group tries to take a comprehensive approach to lightning protection, as well. The company has several brands, including PolyPhaser and Transtector, that enable it to “protect everything from the top of the pole to the inside of a signal house,” says Jason Mies, the company’s national transportation manager. And under its RO Associates brand, the firm will send a crew out to conduct ground audits and site surveys to ensure railroads are implementing proper grounding and bonding concepts.

Although Protection Technology Group has been serving the rail industry for years, its primary customers are telecommunications companies. But now that railroads are implementing PTC and transitioning from radio communications to wireless, the firm’s railroad revenue has doubled, says Mies. He expects the business growth to continue.

“Right now, the big concern is the new 220 MHz radio, and that radio for PTC has to be up and running at all times,” he says. “If that radio goes down for any period of time, they have to stop the train. For that reason, railroads are looking for the best form of lightning protection to put on the radios.”

Traditionally, railroads have used gas tube coaxial connect RF protectors to guard radios from damaging surges. But those gas tubes degrade over time and still allow a lot of transient energy through to the equipment, says Mies.

“These old protectors were doing the job, but that’s when radios were only being used for communications; they weren’t needed for safety, no one’s life was on the line and a train load wasn’t dependent on a radio being up and running,” he says. “If a radio got damaged, it wasn’t a major catastrophe.”

For railroads that need more reliable lightning protection for radios and other equipment using coaxial cable to transfer information, Protection Technology Group’s Polyphaser brand offers a coaxial RF protector that features “filter” technology. The filter unit reacts more quickly and reduces energy throughput compared with gas tubes, and doesn’t degrade over time, says Mies.

Protection Technology Group’s Transtector brand offers lightning protection for data lines using Category 5 or twisted pair cables. Typically, railroads have used surge protection technology relying on one primary component, such as spark gaps, gas tubes or metal oxide varistors (MOVs). However, with more sophisticated electronic equipment being installed for PTC applications, railroads will need more advanced surge protection technology, Mies says.

That’s why Transtector now offers what Mies calls a “hybrid” design featuring MOV and silicon avalanche diode (SAD) technology that “will let next to nothing through as far as surges and transients go, and it doesn’t have to be monitored or maintained.”

“There’s no perfect technology — every single type of surge suppression technology has some kind of a weakness to it,” says Mies. “So we take what we know about the negative aspects of MOV technology and the positive aspects of SAD and put them together so we can get the best of both worlds.”

Built-in protection

While some firms provide railroads with all-encompassing lightning protection services, other suppliers are tailoring their product designs so equipment can better tolerate a lightning strike.

In 2004, RailComm introduced RADiANT^™, or radio integrated antenna, data radios. The product packages a radio and RF antenna together, helping to address RF antenna cables’ susceptibility to moisture and signal degradation, says RailComm Chief Technology Officer Andy Kunzmann.

“The good news is that we packaged all of that energy into a very robust, sealed enclosure and solved water intrusion problems,” he says. “The bad news is that we put the sensitive electronics way up in the air, so we’re on the golf course holding the umbrella up.”

That’s why RailComm in 2007 introduced a redesigned version of the RADiANT that features built-in power and serial data transient protection. The radio now includes a transient protection board that helps channel the lower-voltage transients that might get through typical lightning protectors and still damage radio components.

RailComm has applied the same concept to its integrated automation controller, a field controller product platform designed to control switch machines, remote heaters, blue flags and other field equipment. The company plans to soon introduce the technology on its universal switch machine controller software to replace original equipment manufacturers’ switch machine controller products that have failed.

“It’s all in direct response to what we’ve learned over the years,” says Kunzmann. “Where we see failures occur, we look to improve upon the product and incorporate this protection.”

LaMarche Manufacturing Co., which is represented by Arthur N. Ulrich, also is working to protect its battery chargers and power supplies from lightning strikes.

“The railroads themselves will use standard surge protection that handles heavy surge currents from lightning, but because the equipment can now react so much faster — and because devices are more susceptible [due to the] close spacing between them — we need to protect equipment at a couple of different levels,” says Tom Ulrich.

Through in-house testing, the company identifies weak spots in product designs where surges can cause equipment failure, then tweaks the designs as needed.

“Damage can be caused by the way your grounds are routed in your equipment, by the spacing of components on the boards and the way the traces are laid out on the circuit boards,” says Ulrich. “We try to design those with lightning and surge protection in mind, and we’ve also added some components in the way of MOVs and silicon diodes that will conduct when they see higher-than-normal voltage and safely route the surge to a ground path.”

During the past two years, Arthur N. Ulrich has teamed up with Alset Corp. to test a device that could disconnect power to a bungalow if a storm was approaching. An antenna-type device placed on site would monitor changing atmospheric conditions while a wire running into the ground would measure ground potential rise, which occurs when large currents flow into the earth. Once a storm was detected within five miles of the location, the device would cut power and the bungalow would operate off a battery system until the storm passed.

“It was a very unique approach that had very good success, but it isn’t the cheapest of approaches, so railroads at this point don’t want to spend the money to add it,” says Ulrich, adding that the product could be resurrected if railroads found a need to implement the additional protection at critical sites.

In the meantime, suppliers are trying to make sure they have adequate lightning protection products at the ready. And, if recent history is any indication, they will continue to update and modify products as railroads’ lightning protection needs mount and electronic systems become more sophisticated.