I have a few ideas that might work for you:
1) Easiest one, check if this command is still working. In the Kindle Menu’s Search bar, search for “~ds” without quotes. If it works, your Kindle will not go into screensaver until you reboot it.
2) Your firmware is <5.13.3, so good news you can get JB! Look for KindleBreak in the Kindle Developer’s Corner.
With this, you can install KOReader, which has Keep Alive Plugin, which will make sure to keep Kindle up.
3) Alternatively, with JB there are other ways to make this happen, like making your own screensaver of the train schedules and putting Kindle to sleep — arguably the best solution for your battery as well
Or just something manual with a script. But first please try the methods 1 and 2.