The Dallas Streetcar debuted in April of 2015 and the current system runs on a 3.2 round-trip line. The streetcar is a hybrid, designed by Brookville Equipment Corp., the first of its kind in the United States. John Rhone, VP capital design and construction, Dallas Area Rapid Transit (DART) said that one of the most exciting parts of the project was working with Brookville and to see the streetcars technology develop.
Design innovation
Being a hybrid, the streetcar is designed with a battery, which allows for the streetcar to go off-wire in places.
“It was driven by the historic Houston Viaduct Bridge, really we were restricted from providing any sort of structure for the overhead catenary on that bridge,” said Rhone. “That really drove the decision for the off-wire technology. There are not currently any other areas that we operate that are off-wire.”
One question that often arises when considering a hybrid streetcar is the battery and its ability to adapt to different climates. Rhone says that the weather in Dallas can face extreme cold temperatures and hot temperatures in the summer, and operators have had no issues with the battery or the energy storage system.
“The OESS, is essentially two strings of redundant lithium-ion batteries that are integrated into the vehicle propulsion and auxiliary power systems and operate independently of the overhead contact system (OCS),” Adam Mohney, marketing specialist, Brookville explained. “It is an alternate power source for the vehicle, kind of like a mobile device or laptop which can use a battery to operate or a power outlet to both charge and operate simultaneously, but obviously on a much larger scale.”
The OESS charges while connected to the OSC on the spaces where the streetcar is able to have the overhead catenary. It also charges when plugged in at the vehicle maintenance facility.
“The system has sensors that monitor current power demands and state of charge and can be tracked through the VCU by the operator or remotely by transit agency staff. At the last station stop before the off-wire portion of the line, the pantograph is lowered in a matter of a few seconds, the vehicle switches to off-wire mode and begins drawing power from the OESS. At the first station stop with OCS connection after completing the off-wire run, the pantograph is raised and reconnected, switching to OCS power and recharging the OESS,” said Mohney.
Brookville’s technical team needed to account for variables when the streetcar switches from wire to off-wire. Mohney explains that they needed to take into account track grades, distance, traffic patterns and scenarios, passenger loads, propulsion, auxiliary power loads, and how the OESS will interface will all of the other vehicle systems.
Operator education
The streetcar operates out of DART’s light rail facility.
“We were actually able to accommodate the streetcar and the operation of it in our central rail operating facility, our yard for the light rail transit system,” said Rhone. “We are able to store the vehicle and maintain it in the yard and we can operate from the yard onto the main line of the transit system until we reach the portion of the system that is dedicated for the streetcar.”
Rhone said that the mechanics that were utilized in maintaining the streetcar are also light rail technicians.
“There was a series of training courses that they attended for preventative maintenance and directive maintenance associated with the streetcar. So they would understand what it would take to not only preform preventative maintenance; but when needed preform corrective maintenance, trouble shooting and diagnostic testing,” said Rhone.
The streetcars themselves are equipped with a train operators display (TOD). The TOD is integrated with the vehicle control system and it allows for the on-board streetcar operators to be alerted of how much remaining power there is. Rhone said that DART wanted to have the option to provide instant insights to operators as well as offer a real time remote monitoring system.
Dallas Streetcar in the process of expansion
The second phase that DART worked on was the Southern Extension, which opened on August 29. The Southern Extension is .75 miles and was the first extension to be added onto the existing streetcar. Rhone said that DART is also looking to construct the Northern Extension, which will be from DART’s Union Station to Dallas’s Omni Hotel.
“We’re hoping to continue to grow the streetcar system and we’re hoping to be the leading edge in innovation in the off-wire technology, and utilize the battery system,” said Rhone.
One such way that Rhone said that Dart hopes to integrate off-wire technology is where the streetcar loops around the Omni Hotel and back to the Union Station. Rhone explained that once they complete the Northern Extension, they plan to link the streetcar to DART’s historic trolley system.
The future of hybrids
Both Rhone and Mohney both expressed that as it was the first hybrid system in the United States it is a great feat for both DART and Brookville. Mohney said that Brookville is working on developing streetcars within other systems in the United States; including in Oklahoma City and Detroit.
“Many variables would need to be reconsidered for each unique alignment, as no two alignments and climates are the same, so Brookville has the opportunity to tweak and modify the system to best suit each city’s needs.”
That includes adjusting for each different climate. Mohney outlined that there are several benefits of an OESS system, including making streetcars a most flexible option for agencies.
“OESS can keep historic districts and landmark areas free of overhead wire while also providing rider access directly to these locations or it can help overcome pre-existing infrastructure challenges such as clearing an overpass or crossing a bridge, as in Dallas' case,” said Mohney. “It can also potentially save cities with on the cost of wayside systems by reducing the amount of poles, substations and wire needed along an alignment. We see it as a solution for reintroducing streetcars to American cities without the challenges associated with installing OCS along the entire route.”
