71-931 "Vityaz" () is a Russian three-unit six-axle 100% low-floor tram car created by LLC "PK Transportnye Sistemy" (transl. "Transportation Systems", PK TS) and manufactured in cooperation by PK TS and Transmashholding at the facilities of the Tver Carriage Works. Currently exists in two versions: the basic model Vityaz and 71-931M Vityaz-M modification with modified front and rear mask, different interior and Russian-designed traction motors. In operation in St. Petersburg, Krasnodar and Moscow's Bauman, Oktyabrskoye and Rusakov depots.
71-931 "Vityaz" () is a Russian three-unit six-axle 100% low-floor tram car created by LLC "PK Transportnye Sistemy" (transl. "Transportation Systems", PK TS) and manufactured in cooperation by PK TS and Transmashholding at the facilities of the Tver Carriage Works. Currently exists in two versions: the basic model Vityaz and 71-931M Vityaz-M modification with modified front and rear mask, different interior and Russian-designed traction motors. In operation in St. Petersburg, Krasnodar and Moscow's Bauman, Oktyabrskoye and Rusakov depots.
== Design == The car is based on three rotating 2-axle bogies which design was patented by PK TS. The main design feature of said bogies is that the traction motors are located below the floor (compact enough for allowing low floor level) so wider gangways are allowed despite the bogie being rotational. The traction drive is asynchronous, Vityaz model uses Czech-designed traction motors which were replaced with Russian-designed in Vityaz-M model. Each axle is powered by one 72 kW motor with a total output of 432 kW.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).