I did more work today on Ship Upgrades. A lot of it was getting the framework expanded more and adding supporting code. I did add a Shipyard module into the game and the first one was installed at Fort Jackson in the Marvin(1) system. It's a level 2.0 shipyard and currently a ship can upgrade to Class 2.0 there.
That's likely to be the only non-player made shipyard in the game when it starts, and any player will be able to upgrade a ship to 2.0 there without having to get authorized. It will be up to players to build colonies that are capable of supporting Shipyards bigger than 2.0, and I expect this will likely take a good bit of time to accomplish. Right now I've got the build time for a Shipyard module set to 1 week, so a 1.0 Level Shipyard will take one week to build along with a lot of materials. A 1.1 Level Shipyard will take 10% longer, and so on.
Also, Shipyards will likely only be able to build at colonies of a certain class. Right now I'm thinking Class 5 colonies, but I may lower that to Class 3 but have a restriction that it must be Class 4 or higher to upgrade the Shipyard beyond a certain level.
So it may be up to two years after the game starts before player-built ships larger than Class 2.0 appear in the game. I expect to hear a lot of howling about this, but oh well. I planned from the beginning for this game to have a very long timespan and require long term strategic planning. There will be possibilities of finding derelict ships that are larger than 2.0, but these will be fairly rare and require a good bit of exploration to find.