The train needs to be in constant motion, which happens due to its perpetual engine (as seen on the blueprints in the opening sequence) called the "Eternal Engine". If the train were to stop for more than thirteen minutes, everyone would freeze to death.
Based on the 1982 French graphic novel Le Transperceneige, later retitled Snowpiercer, written by Jacques Lob and illustrated by Jean-Marc Rochette.
Was renewed for a second season a year before the first season even aired, as the show was originally set to air in 2019, but was delayed to 2020 due to its move from TNT to TBS, a move that was later reversed.
The original pilot, directed by Scott Derrickson and written by Josh Friedman, was never released and only a few shots from it were used in the series. Thirteen of the actors in the original pilot continued on into the series, but several were recast as different characters.
The train consists of 1001 cars with a total length of 10 miles (16 km). Assuming the majority of the cars are the same length (as indicated by the exterior shots of the train), most cars are around 15 metres long, which seems very short compared the standard length of around 25 metres in the US (as of 2020). However the 10 miles might just be an estimate by the tail passengers, and in the real world the general rule is that the faster the train, the shorter the cars.