Not really a surprise, but when Calgary was looking for new LRV's to add capacity for future extensions, they chose Siemens. The SD-160 is a variation of the SD-100. The SD-160 has doors for high loading platforms, whereas the SD-100 is configured for street level loading. The cars were built by Siemens Transportation Systems (STS), and are powered by AC traction motors like U2 AC cars #2101-2102. The SD-160 was supposed to be able to run with the original U2 cars, but it took a lot of work to get that to happen. Initially, the SD160 fleet only ran with other SD160's. Later this included the U2 AC cars until their retirement from revenue service. For a period of time however, due to car shortages there were consists with SD160's on the ends and a U2 in the middle, with the train running in a degraded mode to match the U2's performance. This lasted for a relatively short period of time. 2201-2020-2202 were run as a train during the inaugural run on the SD-160 on July 3, 2001. In the summer of 2002, sightings of the U2 AC powered cars running as slave cars between 2 SD160's were quite common. The reverse, an SD-160 running as a slave between the 2 U2 AC's, happened just as often. Changes made to the cars over time included the installation of low profile resistor boxes (the grey rectangular boxes). Starting in 2009, the cars had work performed, including repainting into the red livery. They also attained A/C, sealed windows, and roof skirting similar to the 2010+ restlyed SD-160's. Starting in 2015 these cars, and as well as the Series 6 and 7 SD160's were sent out to Siemens for rebuilding at their Sacramento plant. Upon their return, they were not capable of running with the unrebuilt SD160's, although they can run with the Series 8 SD160's.
