Regarding Astro Train Stations

[Thinking42Man]

So... I got tired of having the trains come through my systems, and decided to destroy the station. I put down 15 laser turrets and 15 mrl turrets, but to my dismay, they were still at 70%+ hp after a good forty five minutes of letting the turrets shoot them. There must be either a way to destroy them efficiently that I'm not aware of, or there is something wrong. I will appreciate any insight.

[deMangler]

Dunno if it's the best way, but I generally use bombers to destroy them.
dM

[jordot42]

     Another way is to have 1500 ships firing at it at once. Takes no more than about 30 seconds that way.

[Doddler]

I've more or less given up destroying train stations.  Unless you're in some corner of the galaxy where you can reasonably destroy every station the trains might want to go to, then no matter what you do trains will still end up flying across your systems.  To make it worse, if you do somehow manage to remove train presence from your own systems, you increase it in AI systems because the number of trains in use doesn't actually change.  All you've really done is drastically increase the odds that the next time you go to attack an AI system it will be filled with one to five (oh good god it's scary) of the dreaded boost trains.  Leaving train stations around and living with the trains makes it less likely that the trains will bunch up in bad places.

[x4000]

I tend to get my back into a nice corner and destroy them to keep them out of my space. On 80 planet maps, this tends to make a very nice difference with no ill effects of bunching for me.

To the original question, mist big structures of odd types are considered "heavy defense," something which bombers, tanks, and certain starships are excellent against (see the startship descriptions, I forget which ones specifically at the moment). With a goodly number of bombers, these things go down extremely quickly.