There are many solutions, including a much simpler ones like cars that can move on both standard and wide gauges https://en.wikipedia.org/wiki/SUW_2000 https://

There are many solutions, including a much simpler ones like cars that can move on both standard and wide gauges https://en.wikipedia.org/wiki/SUW_2000 https://en.wikipedia.org/wiki/SUW_2000 Or automatic unloading of this kind: https://www.youtube.com/watch?v=ZzG-pizgqUQ https://www.youtube.com/watch?v=ZzG-pizgqUQ Imagine this but with grain instead of sand and over a Vistula river where ships going to Gdańsk are waiting. But the main problem is too few trains. Sea transport is so efficient compared to rail, that combined Polish and Ukrainian cargo trains are far too few in number to move all that grain in time. You'd have to buy order of magnitude more trains.