The Effect of Transmission Lines on Railroads

This item is excerpted from an article at T&D World. Read the full article here:

In the electric industry, many workers are familiar with induced voltages and their potential impact on electrical work. Typically, crews are informed about other nearby power sources in the morning job brief, prior to the start of construction. Something not often discussed is that the same concept of voltage being present on supposedly dead conductors also affects railroad signaling, operation and safety.

In the modern era, railroads are moving to much more complicated signaling while still using the rails as the fundamental medium for communications. They have moved away from DC systems and now favor alternating-current (AC) frequencies to transfer their signals. This, in coordination with expansive relays and signaling devices, makes the signals much more susceptible to power line interference, which also is AC. Making the issue even more significant is the frequencies used often approach power line frequencies (60 Hz in the United States) and their harmonics, which makes it much easier for interference to occur.

Because of recent changes in railroad signaling technology, all railroads are becoming more and more susceptible to interference. If not appropriately mitigated, this interference could cause railroads to shut down and even damage their signaling equipment. In many cases, the interference also can make it difficult for the utility to obtain line outages. As the utility continues to use land next to railroads, induction studies should be completed more and more frequently to ensure the two systems can operate in harmony.”

BONUS: Here’s a video of a line being strung across an active railroad track:

Fort Collins couple builds Train Alert system to help reduce traffic backups

Read the full article here: Excerpted below.

A camera mounted on the side of their house and a homemade computer program are the nuts and bolts behind the service, called Train Alert, which launched its first version Dec. 8.

Train Alert automatically sends out tweets and web alerts to subscribers with estimated times an oncoming train will arrive at major street crossings in Loveland and Fort Collins.

All elements of the Train Alert system are homemade and low-cost, the couple said. Keeping the cost low was “a fun challenge,” Kathy Haselmaier said.

Jim Haselmaier, who has some background in engineering and software development, used open-source image analysis software and a program he wrote himself in the programming language Python to create the train monitor. The image analysis “routines,” which he obtained from an online library called Open CV, do “some basic but astonishingly cool tasks,” Haselmaier said.