QLine tech powers cars and fuels Wi-Fi

Jim Lynch
The Detroit News

Detroit — They’re visible in the grainy photos of Detroit’s past: metal arms stretching off the roofs of the city’s streetcars to connect with electrical lines running overhead.

Those arms, or pantographs, are an old-school technology, but one the city’s new breed of streetcars will utilize in a much more limited fashion. The cars built by Pennsylvania’s Brookville Equipment Co. operate “off wire” roughly 60 percent of the time over the 6.6-mile route around Woodward Avenue.

Each Liberty model comes with a battery tucked under each end of the car that stores an electrical charge from the wires. It makes Detroit’s newest public transportation option, which began public rides Friday, a mixture of old and new.

QLine street car going down Woodward Ave. in Detroit, Michigan on May 10, 2017.

“The On-board Energy Storage System (OESS) then acts as the primary power source when the pantograph is lowered and disconnected from the overhead wire,” wrote Adam Mohney, a Brookville spokesman in an emailed response to questions.

The lithium ion batteries can power everything from the streetcar’s movement to heating and air conditioning. Additional electrical charge is generated each time the streetcar is forced to slow or brake thanks to a combination of technologies.

“(The cars’) dynamic braking system uses a combination of electric braking provided by the traction motors, friction disc brakes, (electromagnetic) track brakes and sand application for adhesion,” Mohney wrote. “...The energy created while braking is captured and returned to the power grid or OESS.”

Battery charge can be monitored by the on-board operator as well as remote monitors to ensure there is sufficient power to keep the QLine streetcar in motion. When the streetcar comes to stop at one of the 12 stations on its north-south route, other technology kicks into gear.

A new trackless trolley debuts in Detroit in 1925. Streetcars with poles reaching up to electrical lines had been in service in the city since 1886.

Sensors and hydraulic equipment adjust the streetcar’s height to match up with station curbs precisely, making it easier for riders in wheelchairs or those with strollers or bikes to get on or off without trouble.

The stations themselves will help riders keep track of the train locations with monitors that post the estimated arrival times. Once on-board, riders are given a slick way to pass the time: each car provides free Wi-Fi access, with what might be surprising speeds.

While crews were digging up Woodward Avenue to put in the QLine tracks, they also laid fiber optic lines for local Internet company Rocket Fiber. The company, whose headquarters is located just off the streetcar route, debuted in November 2015 with the promise of delivering the fastest Internet speeds in Detroit.

Marc Hudson, the company’s co-founder and CEO, said QLine riders will enjoy speeds of 80 to 100 megabits per second while the cars are on the move, and somewhere between 100 and 200 megabits per second while in the stations. An average home Wi-Fi user typically gets speeds of 20 to 25 megabits per second.

A pair of lithium ion batteries at each end of the QLine cars allows for the storage of electricity captured from overhead wires as generated during breaking. They allow the QLine to top operate without being connected to overhead wires, or "off-wire," on 60 percent of their route.

“This service will be comparable to a very high-end residential product for most people,” Hudson said. “We had a unique challenge in how to put high-speed Wi-Fi on a moving streetcar. It’s something that presents a lot of problems with Wi-Fi technology.”

The underground fiber optic lines that run beneath the track connect to a radio transmitter at each station, mounted atop a poll. The signal is then relayed to a receiver atop each car while it is in motion.

Hudson said that setup should guarantee reliable service — even during times of peak usage. Downtown Detroit regularly draws massive crowds to its sporting events, concerts and festivals, but those numbers should no interfere with performance.

While riders may enjoy their Wi-Fi experience, the new streetcars do not provide charging options for cell phones.


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