How to defend train tracks?

[Dunhill]

No matter what I do, aliens always seem to be able to damage them, and doing a roboport with its own dedicated repair pack storage to every defensive track unit seems a bit absurd. Is there something I can do to have them simply completely avoid tracks and towers? I haven't played with aliens on for years because of this.

[Fel]

Enemies don't attack train tracks, the only way for them to damage them is if they are attacking a train that's on it (usually because it rammed them) or something else that's very close.
This means that tracks are pretty safe as long as there is no nest directly next to them.

If you really want to protect them, the best way is the good old wall and defenses around a much bigger area than what your base and outposts cover, coupled with anihilating every nests within the walled area.
It's a pretty big project that requires a lot of resources and quite a bit of logistics (or power if you go for pure laser towers instead as defenses).
The biggest benefit is that if you make it quite a bit further than your pollution cloud (to account for how it will enlarge as well) you can prevent all attacks since you can be sure that no new nests will be made in range of your pollution (if you didn't miss any nest inside of course).

[Nonotorious]

Set up some artillery to clear nest near the tracks? My last map i had an artillery train and set up defensive stations to clear nests, a few dozen lasers and an artillery train is easy to set up and mobile.
My current map just has a wall around everything.

[Drizzt]

Originally posted by Smoke:

No matter what I do, aliens always seem to be able to damage them, and doing a roboport with its own dedicated repair pack storage to every defensive track unit seems a bit absurd. Is there something I can do to have them simply completely avoid tracks and towers? I haven't played with aliens on for years because of this.

sounds like you need a Strategy of some kind.... :-P

(for anyone else reading this, i recently made a thread about the genres of Factorio - and the OP and i had a disagreement about Factorio's place in the Strategy genre)

personally i almost always play with biters enabled, since to me they are the vital component that turns Factorio from being a relaxing, logistics and base building Simulator (which is nice, and i do occasionally play a few of those relaxing games), into a game that requires both short and long term strategic planning, as well as a little combat tactics thrown into the mix

i usually always surround my base with a belt fed turret wall perimeter (can load one side with ammo and the other with coal and use burner inserters - no need for electricity) - which gives me time to build - and i extend the perimeter periodically - usually wanting to get to a point where i have gone coast to coast on all sides

then i extend my radar coverage outside of the perimeter - surrounding the radar and power pylon with a few (usually 4) fully loaded turrets and a wall

and then i make outposts around distant resources patches which are connected to a rail system, with the entire resource patch and the train loading station surrounded by another belt fed turret perimeter - and i just keep a steel chest full of ammo and one full of coal and it'll keep it defended (although occasional visits to repair spitter damage may be needed - since the attacks will continue to increase in frequency, biter count and biter size)

as mentioned the biters won't attack the bare tracks - they are more likely to attack any power pylons they pass on their way to their destination

and their destination is always a pollution centre, and generally a straight line route - so as long as your pollution producing equipment is inside a turret perimeter you can keep them at bay

like i said in my other post, it's certainly more Tower Defence than Tactical Combat RTS - but that still counts as part of the Strategy genre in my book - especially with the added scouting missions, and missions to set up radar or mining outposts, or to clear biters

but yeah - much more fun and challenging with biters - but pretty zen and relaxing without them :-)

[knighttemplar1960]

Your issue may be that you have set up defense units around your tracks.

Spawners that are inside your pollution cloud use the pollution to produce bugs that then move to a rally point. Once enough have gathered they move in a wave to attack. They path to the largest and closest source of pollution. If a higher priority target comes into their perception radius they switch to it instead. Turrets and radars have a higher priority than the pollution source and if those come into their perceptual radius they will switch to attacking those. A player is an even higher priority target than military assets so if you come into range they will switch from attacking your turrets to attacking you.

If the bug's pathing to the highest priority target is blocked they make a few attempts to path around those objects and if they can't they will attack those objects to remove them from their path. That includes, among other things, walls, gates, pipes, trees, and rocks.

Bugs that are in attack mode will only attack things that have low priority after all higher priority targets in their perception radius are eliminated. Rails, belts and splitters, and power poles are very low priority targets and only power poles that block the bugs path will be attacked by them. Rails and belts don't block their path so when you place a power pole make sure that the area around it is clear enough that the bugs can path around the pole.

Outside your pollution cloud bugs will completely ignore your rails since they can't block their movement unless the bugs are damaged by something which in that case could only be a passing train.

The solution is as Fel stated, get rid of your defense outposts outside your pollution cloud so that the bugs aren't triggered by military equipment like radars and turrets. Clear spawners that are outside your pollution cloud but close to your rails so that passing trains can't damage them and trigger their attack mode. (A spidertron operated by remote control is ideal for this). Use artillery to clear out spanwers that appear near your rail road tracks outside the gates where your trains exit and enter your base. Doing those things should eliminate 99% of the problems you are having.

[Dunhill]

Originally posted by knighttemplar1960:

Your issue may be that you have set up defense units around your tracks.

Spawners that are inside your pollution cloud use the pollution to produce bugs that then move to a rally point. Once enough have gathered they move in a wave to attack. They path to the largest and closest source of pollution. If a higher priority target comes into their perception radius they switch to it instead. Turrets and radars have a higher priority than the pollution source and if those come into their perceptual radius they will switch to attacking those. A player is an even higher priority target than military assets so if you come into range they will switch from attacking your turrets to attacking you.

If the bug's pathing to the highest priority target is blocked they make a few attempts to path around those objects and if they can't they will attack those objects to remove them from their path. That includes, among other things, walls, gates, pipes, trees, and rocks.

Bugs that are in attack mode will only attack things that have low priority after all higher priority targets in their perception radius are eliminated. Rails, belts and splitters, and power poles are very low priority targets and only power poles that block the bugs path will be attacked by them. Rails and belts don't block their path so when you place a power pole make sure that the area around it is clear enough that the bugs can path around the pole.

Outside your pollution cloud bugs will completely ignore your rails since they can't block their movement unless the bugs are damaged by something which in that case could only be a passing train.

The solution is as Fel stated, get rid of your defense outposts outside your pollution cloud so that the bugs aren't triggered by military equipment like radars and turrets. Clear spawners that are outside your pollution cloud but close to your rails so that passing trains can't damage them and trigger their attack mode. (A spidertron operated by remote control is ideal for this). Use artillery to clear out spanwers that appear near your rail road tracks outside the gates where your trains exit and enter your base. Doing those things should eliminate 99% of the problems you are having.

Originally posted by Drizzt:

Originally posted by Smoke:

No matter what I do, aliens always seem to be able to damage them, and doing a roboport with its own dedicated repair pack storage to every defensive track unit seems a bit absurd. Is there something I can do to have them simply completely avoid tracks and towers? I haven't played with aliens on for years because of this.

sounds like you need a Strategy of some kind.... :-P

(for anyone else reading this, i recently made a thread about the genres of Factorio - and the OP and i had a disagreement about Factorio's place in the Strategy genre)

personally i almost always play with biters enabled, since to me they are the vital component that turns Factorio from being a relaxing, logistics and base building Simulator (which is nice, and i do occasionally play a few of those relaxing games), into a game that requires both short and long term strategic planning, as well as a little combat tactics thrown into the mix

i usually always surround my base with a belt fed turret wall perimeter (can load one side with ammo and the other with coal and use burner inserters - no need for electricity) - which gives me time to build - and i extend the perimeter periodically - usually wanting to get to a point where i have gone coast to coast on all sides

then i extend my radar coverage outside of the perimeter - surrounding the radar and power pylon with a few (usually 4) fully loaded turrets and a wall

and then i make outposts around distant resources patches which are connected to a rail system, with the entire resource patch and the train loading station surrounded by another belt fed turret perimeter - and i just keep a steel chest full of ammo and one full of coal and it'll keep it defended (although occasional visits to repair spitter damage may be needed - since the attacks will continue to increase in frequency, biter count and biter size)

as mentioned the biters won't attack the bare tracks - they are more likely to attack any power pylons they pass on their way to their destination

and their destination is always a pollution centre, and generally a straight line route - so as long as your pollution producing equipment is inside a turret perimeter you can keep them at bay

like i said in my other post, it's certainly more Tower Defence than Tactical Combat RTS - but that still counts as part of the Strategy genre in my book - especially with the added scouting missions, and missions to set up radar or mining outposts, or to clear biters

but yeah - much more fun and challenging with biters - but pretty zen and relaxing without them :-)

The issue is that killing aliens is very time consuming and I was really hoping there is a way of killing only the ones in my way, without having to push a line of defensive walls outwards, killing everything inside them. So far, other than this, aliens haven't really been an issue without an obvious and easy solution, but when I last got to this point, it just slowed the game down drastically, and it simply wasn't fun anymore. Since then, we got nukes and artilleries, so it likely isn't as tedious as it used to be, but I still want to avoid it as much as possible. And about the tower defense part; I enjoy it, but it's no longer tower defense, it's finding the fastest and cheapest way to expand, and it seems as avoiding the defense part is the way to do it.

About the tracks being attacked; as was mentioned, they only go after them once a train hits them, but they do go after them. It's been a while since I played with aliens, but I'm almost certain I started building tiny laser turret outposts around every other power pole because I had biters destroy some of them.

[knighttemplar1960]

Before version 1.0 biters would occasionally attack lone power poles and rails but since 1.0 came out I have not had a biter attack a non-pollution producing object outside the pollution cloud. I had one desert start where I didn't have much water in my starting pond and I put an off shore pump on the closest lake and ran underground pipes into the base from there. The only place the biters attacked the underground pipes was near the walls where my turrets were.

Killing aliens is only as time consuming as you want it to be. Like every thing else in the game there are ways to automate it. All you have to do is set up the supply chains.

I personally build "clearing outposts." I drive a train out laying rail from the engine as I go with my bots. When I get to a spot I want to clear out I drop a clearing base blue print. My bots build that and the oil and ammo on my supply train fill the turrets. The 2 stations turn on for supplies (general and artillery) and I drive the supply train back to the base while the automated system exterminates all the bugs and spawners in artillery range. 2 or 3 of these clear out and keep clear a huge swath. I can then wall in at my leisure the territory and resources cleared out and pick up the outposts and reuse the materials to make clearing outposts the next time I need to expand.

You can do something like that or if you don't like clearing out nests more than once you can use railsworld settings, set the bugs to peaceful, or turn the bugs off. Its a sandbox game. You can set it up how ever you want to play within the programs ability to do so and if that isn't satisfactory you can add mods.