A setting that allows you to change the maximum size of a station.
The station spread is the maximum distance between two station tiles in the same station. There is a limit to how spread a station is allowed to be. If the station already covers this amount of tiles in a certain direction, you cannot add any other part to the station in this direction. With this patch you can change the maximum station size to anything between 4 and 64 tiles, the maximum value being the same as the longest train you can have. Be careful if you are not using the Yet Another Pathfinder pathfinding though: The game will slow down and then become unstable when you set this to a value higher than the default of 12.
The default station spread is 12. You can change this value through the configure patches -> stations window or use the following syntax in Openttd.cfg:
[patches] station_spread = 12