The Toronto Transit Commission (TTC) operates bus, subway, streetcar, and paratransit services in Toronto and York Region in Canada. More than 1.5 million passengers use the system during regular workdays.
With more than 460 Mio passengers in 2019 it is the most utilized system in Canada and considering the whole of North America it is ranked third right behind New York and Mexico City.
The subway in Toronto was opened in 1954 and is the oldest subway system in Canada. The whole subway network consists of 4 lines (two more lines are currently in construction phase) with a total length of 80 km. Toronto has a special gauge of 1495mm (4 ft 10 7/8 in, also called Toronto Gauge) on the three oldest subway lines and on their streetcar/tramway network.
Rhomberg Sersa North America has a successful working relationship with TTC since 2014. This working relationship started with rail grinding services on the streetcar lines as well as on the Scarborough Rapid Transit line (elevated track). In 2018 Rhomberg Sersa was awarded a multi-year contract for rail milling services for the TTC subway lines. Rail milling can be characterized as a dry cutting process, where material is cut out of the rail surface in the form of chips. Contrary to the abrasive process of rail grinding, rail milling only puts minimal amounts of energy into the rail surface causing only a minor temperature increase. Any unwanted material transformation at the rail surface can be completely prevented. The process by- products – the milling chips – are efficiently picked up by a vacuum system and are stored on-board the machine for later recycling. Furthermore, no dust and no sparks are produced by this dry cutting process, reducing potential fire danger to a minimum. The milling process itself only requires minimal operator intervention, thereby reducing the potential for operating errors to a minimum. Rail milling shows clear advantages with respect to adjustable metal removal rates, high precision transversal and longitudinal target profiles as well as superior surface quality.
To provide milling services for TTC (and the rest of North America), Rhomberg Sersa formed a joint venture with the international milling service provider LINMAG (a sister company of the milling machine OEM LINSINGER). The JV ordered in early 2018 a milling machine type SF02T-FS LB from LINSINGER. This milling machine is equipped with the latest diesel-electric milling technology and can flexibly remove between 0.3 mm and 1.5 mm of rail material per machine pass. Especially in a tunnel environment the spark and dust free rail milling process offers significant advantages. Furthermore, the machine is equipped with state-of-the-art measurement technology to determine transversal profile, metal removal, longitudinal profile and damage condition of the rail. The SF02T-FS LB is capable of treating mainline track as well as switches and crossings as it is equipped with a switch treatment kit. No dedicated switch milling machine is required. The SF02T-FS LB was designed to fit into most tunnel clearances in North America. Although targeting transit systems this machine has enough work capacity (chip bunker, fuel tank) to also allow for work extended shifts on North American Class 1 freight networks.
First successful shifts were delivered at TTC in late 2018 / early 2019 with a leased LINSINGER milling machine as the ordered SF02 was still in production. In January 2021 the SF02T-FS LB was delivered to Toronto and has commenced working beginning of February 2021. In this milling campaign at TTC Rhomberg Sersa North America is targeting areas with high damage (Rolling Contact Fatigue, Corrugation), high welds and severely worn rails. With milling, it is possible to restore even severely damaged rails and thereby prevent premature rail exchange. Furthermore, the resultant high quality rail surface finish will reduce noise and improve passenger riding comfort.
It is expected that the milling machine will work in Toronto until June 2021 before it will continue to other Canadian and US customers.
