Train is too vulnerable versus green alien(Big problem!)

[Gnarflord]

Well, I see three solutions to your problem.
1. Play in peaceful-mode
If you are annoyed by the combat aspect of the game you can just turn it off. While you still need alien artifacts for research only the biters you attack will be angry. The rest will ignore you as long as they have no contact with the angry biters. And those won't be able to tell anyone about your murder if they're dead.
2. Heavy defense line
Build a fully automated defensive line (like I did. See this post of me viewtopic.php?f=5&t=32819&start=20). It will cost a lot to set it up in the first place, but half the fun of the game is to figure out how to build things efficient and fast. I've enjoyed it, but of course your playing style could differ from mine.
3. Use mods
There's a mod called GunTrains which allows you to load the engine with your preferred type of ammo (shotgun, machinegun or poison capsules). It will automatically attack biters in reach. You could even setup some defense trains which would patrol on your tracks and kill biterbases. Link: viewtopic.php?f=94&t=17099

[SirLANsalot]

umm you guys have...some bug problems there in those pics....just wow, and I know in vanilla the tank cannot handle those bases. A Heavy Tanks mod brings a nice super heavy tank with a cannon that will one shot a base, but be warned, it has a long reload time and can have only ONE round per a stack (so your limited to what the trunk can hold). Its secondary gun is a nice autocannon tho.

I really really really hope .14 comes soon for steam, there are a lot of mods I would like to use to get the equipment slots on trains so they (and the wagons) can defend themselves.

[steinio]

You can activate 0.14 on Steam in the game settings and subscribing to the beta channel.

Greetings steinio