Railway Empire 2

Easily done in a few minutes work;

• Select a new Game.
• Start a custom game in the year 1910.
• Create two stations and connect them together.
• Create a new rail line between those two stations. Choose your locomotive and select a train to your liking.
• Raise the number of trains to 7 (or more) and confirm the rail.

Now, go to the engine shed. Select a different train and choose the "replace engines" in the top right corner. Make sure you've selected all the trains and it will state 7 trains found; replaced them for X amount of coins and replace them with the chosen train.

Select the tick and the achievement unlocks shortly after!