The concept of mass production, where different items are made exactly the same, using uniform parts which can be interchanged, prepares humankind for the Industrial revolution which will change the world as we know it. The full scope of implementation of this concept has to wait until such time as technology develops, but in the Renaissance some things can already be mass produced. The invention of the Printing press allows mass production of standardized texts, and the utilization of uniform planks allows mass production of ships. A new structure is invented in Harbor districts to implement this - the Shipyard.