A team of students and faculty from the mechanical and materials engineering department at the University of Nebraska-Lincoln has come up with a way to prevent many of the accidents that occur when motor vehicles miss rural railroad crossings, as Ben Coxworth writes for Gizmag. It is easy for drivers to miss such crossings because there is often only a sign to warn motorists about them, Coxworth writes. That’s usually because there has been no easy way to provide electricity in such locations, he adds.
The lack of electricity has also prevented railroads from having track health monitoring sensors that could reduce the occurrence of train/motor vehicle crashes, according to an abstract of the team’s article, “Power Harvesting Systems Design for Railroad Safety.” The article appears in the Journal of Rail and Rapid Transit.
Although solar panels could provide some of the necessary energy, the team believes that it would not provide enough consistent power to provide the warning light systems and track monitoring sensors, the article says. To solve the problem, they created several systems to harness power from the rails, Coxworth writes. He adds:
One system incorporates an inductive coil that’s attached to the rail, located above a permanent magnet with a radial magnetic field that’s mounted on the ground. As the rail flexes vertically under the weight of a passing train, the coil repeatedly moves up and down through the magnetic field, generating an electrical current.
Another system the team writes about consists of a strip of piezoelectric material that is mounted on the rail’s underside, Coxworth writes. This material produces an electric charge as the rail flexes when subjected to technical strain during use, Coxworth writes. However, tests found that, although the two above-mentioned systems could provide adequate current to run wireless sensors such as the ones used in the track health monitoring systems, they could not provide enough energy to power warning lights, Coxworth writes.
The team thus created another system, Coxworth writes, “in which the vertical flexion of the rail moves an attached ratcheting mechanism that turns a planetary gearbox … which subsequently drives a generator mounted on the ties.” In addition, the engineers developed a hydraulic system “in which the vertical deflection of the rail drives a hydraulic cylinder that’s wired to a motor,” Coxworth writes. These two additional systems do provide enough extra power much of the time, but that power is not consistent in cold weather, when the low temperatures stiffen the rails, preventing them from flexing as they would need to in order to provide enough power, Coxworth writes.
The team then came up with a fifth system, Coxworth writes. He explains how it works:
In its case, a spring-loaded cam mechanism that’s mounted on the rail is pushed forward by each train wheel, and then springs back to its starting position once that wheel has passed. That oscillating motion drives a generator, in turn producing enough electricity to power warning lights.
The team of engineers writes that every year there are thousands of car accidents involving trains and other vehicles at unprotected railroad crossings, causing hundreds of fatalities and injuries.
In Colorado, there have been 219 accidents at freight rail and light rail crossings since 2010, resulting in 14 fatalities and 50 injuries, as the Colorado Department of Regulatory Agencies Public Utilities Commission (PUC) writes. This year, a train collided at a crossing with an SUV in Valhalla, N.Y., killing six people and injuring at least 12; and an Amtrak passenger train collided at a crossing with an oversized load in Halifax, N.C., with 55 people injured as a result.
Until the systems created by the above-mentioned team are available for use, groups and organizations can get help from Operation Lifesaver, “a non-profit organization providing public education programs in all 50 states to prevent collisions, injuries and fatalities on and around railroad tracks and highway rail grade crossings,” as the PUC press release says. To request a free presentation from Colorado Operation Lifesaver, call 303-739-3677; e-mail [email protected]; or visit the organization’s “Request a Safety Presentation” page.