Judging from the description of your game you simply have too many spaceports.
Spaceports are your ship construction yards, so when you build a spaceport the AI will stock a large supply of strategic resources there for building new ships. Your freighters will transport these requested resources to the spaceport.
But when you have 80 spaceports and only 94 mining stations then your freighters will have dire trouble supplying those resources.
Ideally you should have around one spaceport for every 3-4 colonies. And you should have at least 5 times as many mining stations as spaceports. You should locate spaceports at strategically critical colonies throughout your territory.
So in your case I would reduce your number of spaceports to 20-25. And I would build a few more mining stations for the resources in highest demand - ideally building them near the areas where they are needed the most.
The other single most important thing to do to ensure efficient transportation of resources is to keep your transport routes safe from enemy ships, pirates and space creatures (to/from mining stations, spaceports and colonies).
Hope this helps,
Elliot, judging from what you posted here, it seems that there is a very good argument for designing star bases to gain the recreation and medical bonuses at colonies, and not have as many star ports. A cheap star base with no construction yard, some weapons, and the bonus components seems to be the more ideal way to go. Am I on the right track with this thinking?
I've put some further thought into these options looking at a current game which I plan to test more fully.
Consider late game 2140 (200+ colonies about 50 at maximum population)
The maintenance cost of each Spaceport or Base is about $2k. Weaponry and Shields have been reduced by quite a lot from mid-game as the Pirates are quiet.
The happiness benefits at the colonies are significant, usually around +30, which means I'm able to raise taxes by at least 20% of those colonies.
I would only need a colony revenue of $10k to justify the maintenance cost of the Port when considering this factor alone. Like many I tax only at colonies that have reached maximum population.
Now looking at those colonies at maximum population, all of them provide revenue greater than $10k, except for one planet at 57% quality. Many are far far greater than $10k of course. There are some colonies that are still growing that won't provide this revenue later in the game, but these are exceptions e.g. low quality planets with special ruins e.g. Fortress of Torak.
Consider a new colony
I've picked a new colony at random, quality 67%, all population policy set to assimilate, and tested the options while monitoring resources and freighter movements.
As Elliott has said, the choice to build a Spaceport will result in many more strategic resources being stockpiled at the colony, causing the problems well described in this thread. A Spaceport also deflects freighters from other activities of higher importance e.g. it looked like more luxuries got to the colony earlier and it also seemed like more of the resource outputs of the colony were being transported for sale.
Now a Spaceport or Base still provides happiness benefits that improve the population growth rate. It looks like this is a couple of percent only although it compounds. That said, if you choose Assimilation this will be the dominant factor in growth.
Back to the hard bit, Spaceport Income. Without a Spaceport, looks like freighters will ship resources provided at the colony to a world with a Spaceport, and those resources are then sold. However, with a Spaceport, freighters can go direct to each planet to buy and sell resources i.e. it should mean faster space post income. However, so long as the nearest Spaceports is close, the difference should be minimal.
Early on, Bases provide defence and some colony development support, minimising resource shortages elsewhere and inefficient use of freighters, which spaceports can cause. As the colony development support is small (particularly if you don't mind Assimilating) it also appears quite valid to defend colonies with ships only. Personally though I would use a mix Bases of Ships. Bases will still help on newly conquered planets to prevent revolts.
Later on, there is value in having either a Base at all well developed reasonable quality colonies that are being taxed, since the happiness benefits allow tax rates to be increased, which can be quite lucrative.
With Spaceports I'll now follow Elliott's advice as the developer i.e. Spaceports only at every 3-4 colonies ... but also ensuring travel times for internal empire freight stays small. Where there is a Spaceport; however, there is no real need for a Base.
Again commentary is welcome.
< Message edited by Icemania -- 8/7/2013 4:44:48 AM >