Perimeter defense, 5 designs

This blueprint book contains 5 gun turret perimeter defense designs, each with 5 modules.

For early game and small outposts, gun turrets are enough. For late game, flamethrower turrets are very effective at containing large attacks, which are intensified by artillery turrets.

Laser turrets are completely absent, because a gun turret with good ammo is far more deadly, the energy spent by an idle inserter is a tiny fraction of an idle laser turret, and the slightly larger range they would cover is still smaller than the flamethrowers sitting 3 meters behind.

The designs in the screenshot are 1 (smallest) and X (largest). Here's the full list:

• 1: yellow belts & inserters, sparse turrets & thin walls
• 2: red belts, yellow inserters, dense turrets & double walls
• F: same as 2, plus flamethrower turrets
• 3: same as 2, but with blue belts and blue inserters
• X: same as 3, plus flamethrower turrets, artillery turrets, and roboports

All designs are tileable, obviously. Tiles for 1 overlap in the turrets. Tiles for X overlap in the roboports. The other perimeters (2, F, 3) contain no tile overlap.

For each design, there's 5 modules:

• Basic module, which is a straight line.
  • For the designs without flamethrowers, you can hold down the mouse and walk and they'll all tile correctly if there are no obstacles. This is due to how lamps are positioned.
• g (gate) module, which contains gate walls and an opening in the turret line so you can drive a vehicle through.
• t (train) module, which contains train tracks (2 lanes with a gap of 4 meters).
  • Train modules never contain flamethrowers so your trains won't get damaged, nor artillery turrets, so enemies won't block your train's way.
• c (corner) module, to be used in the outer corners of your base.
• v (v-corner) module, to be used in the inner corners of your base.

In order to make sure you won't have trouble with train tracks, test with the t module first, or, when you place your first turret, make the turret is aligned with the rail grid.

All belts only go one way. I used to have a book that duplicated for each way, but it gets confusing to distinguish which side you've chosen while playing. You should insert ammo to them using a splitter and manually build belts along lake shores. An alternative is simply inverting the belts after the fact, which I still often do in early game if I have a single lake bordering my base.