Issue link: https://geospatial.trimble.com/en/resources/i/1415420
august 2019 csengineermag.com 61 Every New Yorker knows the frustration of subway delays caused by signal failures. The MTA's train signal system is out- dated—it's the same fixed-block signal system that was origi- nally used when the subway system opened in 1904, and it's prone to signal failures that cost New Yorkers time and money every day. In a fixed-block system, if a block of track is occupied by an en- tire train or a single car, the entire block is signaled as unavail- able to every other train operator. But, when a signal switcher fails mechanically, the track is signaled as unavailable to train operators even when there is no train, leading to extra track congestion and delays as operators must use other lines until the mechanical issue is located and corrected. One common cause for signal failures is voltage sag. The MTA has three times as many trains running as the system was designed to optimally handle, drawing more power through lines and signal systems. When the power supply drops, the power draw increases, and unless the supply rises to stabilize the current, signal switchers can malfunction and close blocks of track. As part of the governor's initiative to rehabilitate the subways, contracts went out to install voltage sag cor- rectors at all of the signal switchers, a relatively simple but time-consuming operation due to the immense scale of the NYC subway system. E-J Electric Installation Co., one of New York's largest electrical contracting companies and a regular contractor for the MTA, won the work to install sag correctors across 96 stations. Those stations encompassed all of Brook- lyn, as well as parts of Manhattan, the Bronx and Queens. Inglima's task was to survey signal switchers, take pictures and document measurements, then create blueprints for the installation of the sag correctors. Traditionally, a job like this would require at least two days for each blueprint, but the team decided to try Bluebeam Revu, a PDF based platform for editing, marking up and sharing blueprints, on a Microsoft Surface tablet to see if they could save any time. The experiment worked. "We did 96 stations in 96 working days," Inglima said proudly. "I was able to use [Revu's] signa- ture tools that day, and everything got signed and sent out for production immediately. There was no turnover time, there was no going back to the office. I figure we saved ourselves another 96 days." There was a learning curve, Inglima mentioned, but he was pleased to discover deeper and more intuitive functionality in Revu than he had known before this project. "Once I was kind of comfortable doing a couple things, I'd ask, 'I wonder if there's any way to do that?' And boom, there it was." Even when the technology exists, someone has to be the first to try it out beyond the lab and discover the practical appli- cations. Inglima noted that "The older guys have been doing it with a pen, paper, rulers and colored pencils for years and years. And I show up with my tablet, and I'm in and out… it took me eight hours for the first one, but once you get it, 15-20 stations in, I'm done in five hours." There are still many challenges ahead for the NYC subways, but at least for Inglima and E-J Electric Co., they're taking ad- vantage of the cost-saving solutions that modern technology offers and making the daily commute of millions of New York- ers that much faster. E-J Electric surveys 96 stations in 96 days By Rob Dunn