The Trois-Rivières & Shawinigan Street Railway was a radial running from Trois-Rivières up into the Laurentides, via Shawinigan & Grand-Mère. It fell into the LT&L’s orbit in 1907, soon after electrifying – at 1200 VDC – from Trois-Rivières to Grand-Mère, and operated as an independent railway until 1960 when the LT&L officially merged it into the system.
It was chartered in 1899 to run a line between Trois-Rivières, Shawnigan, and up the west side of Rivière-Saint-Maurice to Saint-Roch-de-Mékinac, where it intended to cross the river and proceed northeast up Rivière to Saint-Joseph-de-Mékanic, but after building two bridges across the river at Saint-Roch-de-Mékinac and Grand-Piles, it had run out of money and couldn’t even afford to electrify north of Grand-Mère (The electrification was only finished after the LT&L purchase when the TRS could access the LT&L’s credit line.)
Initially, the TRS used trolley poles, but in 1928 switched to pantographs so they could use Shawinigan Falls Terminal Railway trackage to move some of their freight operations off city streets.
Post WW2, when passenger traffic started to dry up, the TR&S started cultivating freight traffic instead. In 1950, they purchased the Shawinigan Falls Terminal Railway from the power company that had previously owned it, then in 1954 took over terminal operations in Grand-Mère from the CPR and CNR.
In 1958, the TRS abandoned most of their passenger operations – leaving only a mixed train running from Trois-Rivières to Saint-Roch-de-Mékinac – and dieselised their freight operations.
The LT&L considered pulling down the wires and using a diesel to operate the mixed train, but (a) the city of Shawinigan objected to operating diesels on city streets and (b) the LT&L was starting to discuss a merger with the PV&T, which strongly encouraged leaving the wires up just in case a post-merger LT&L electrified their north shore main line.
In 1996 (post-merger) the LT&L finally started electrifying their north shore mainline between Ottawa, Montréal, and Québec, and part of that project was to rebuild the TRS’s overhead at 3000VDC and replace the class DL2 locomotives it had been using with PV&T motors.
As part of this conversion, the TRS finally abandoned their street running trackage between Shawinigan Falls and Grand-Mère in favor of trackage rights on the CPR’s Subivision St. Maurice Valley, electrifying that section as part of the agreement.
The TRS suffered, as did Canadian railways in general, from the hollowing out of industry in the late 1980s, and by 1996 there was no longer any freight traffic between Shawinigan-Sud and Trois-Rivières, and the formerly comfortable lumber traffic north of Grand-Mère was down to a single lumber mill at the end of the line.
The TRS’s branch across the Rivière-Saint-Maurice at Grandes-Piles, which only survived because Grandes-Piles was the terminal for log drives, was abandoned when those log drives were discontinued in 1996. The bridge was transferred to the town of Grandes-Piles, which operated it as a single-lane highway bridge until 2016 when an ice jam finally took it down.
But to counteract this collapse in traffic, the CPR was in the throes of selling off all of their rail lines east of Montréal, so the TRS bid on (and won) the entirety of Subdivision St. Maurice Valley so they could get access to a couple of industrial parks north of Trois-Rivières.
Thanks to this purchase, there is still quite a bit of freight traffic between Trois-Rivières and Shawinigan, but north of that there is just a single sawmill at Saint-Roch-de-Mékinac.
The mixed train was officially discontinued in 1999, but it is still possible to arrange excursions – either as a a special tourist train or a coach attached to a freight – between the endpoints of the line.
Several of the TR&S’s passenger & combine motors survived into the 2020s as MOW cars for the LT&L. The illustrated one – built by Ottawa Car is 1930 – was restored in 1989 (and again in 2020 after sitting outside for a decade!) and is currently used for fan trips on ORRC rails (there are only a couple of Parsons Vale properties that use trolley poles instead of pantographs, and the ORRC system is by far the largest of them)