First class too expensive
Since the introduction of steam ships in the transport sector in the early 1800s, three classes had been used for passengers, including on railways. First class offered the finest and most expensive service, while third class was the simplest and cheapest.
Initially, all three classes were available on SJ and the largest railways. Over time, however, the difference in comfort between first and second class decreased, and demand for the more expensive class declined. First class disappeared almost entirely.
But after some pushback from the Swedish Parliament, SJ brought back first class on certain trains and routes. Not many people bought first class tickets, as lots of folks got them for free, like members of Parliament.
First class disappears, but not by name
In the 1950s, the International Union of Railways (UIC) agreed to remove first class from trains because there were too few passengers, even internationally. Removing third class was not an option, as that was where the revenue came from.
In Sweden, the reform was implemented in 1956 by removing the expensive first class and giving that name to second class. The most economical travel option was thus renamed second class.