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[celem]

So like the title says I've been playing about with some pillbox designs and thought i'd share what I've found.

Im playing the FD mod so I get a lot of seiges, I use repeating menacing spikes since I get a lot of trapavoid critters but I also wanted my marksdwarves involved from relative safety.

This is what I've come up with so far:

Spoiler (click to show/hide)

z-0

FFFFFFF
Fa      F
F FFF  F
F       iF
FFFFFFF

F-Fortification
a-Armour Stand
i- up/down stair

The important element here is the armour stand.  It defines a barracks that covers the entire structure and has marksdwarf squads assigned.  The purpose of this is to keep your squad in position all of the time without needing to set up some form of rotation/patrol through schedules. 

The other beauty of this is that your dwarves dont even have to stop training to engage the enemy. (To judge by their job display they dont actually stop training. 
I am conducting some TheRapist science to try and determine if they are actually learning from the lesson and engagement simultaneously.)

The shape of the pillbox is cruicial.  Marksdwarves below ?accomplished? can only fire through a fortification that is adjacent to them.
The layout shown above ensures that all members of the squad are always adjacent to a side of the pillbox and thus have that firing arc.
Note that new marksdwarves therefore can only fire from the side they stand on, by using fortifications instead of walls for the interior tile-blockers
however your better marksdwarves can shoot from anywhere to anywhere.

About 15 tiles away from this is a similar model that is slightly longer and contains archery targets rather than an armour stand, assigned to the same squads. 
This gives wide coverage for both ambush spotting and spontaneous engagement, while allowing the squads to behave as normal.
Between the two pillboxes on the z below are the ammo piles.

Its interesting to note that though I always have a viable path between the interior and exterior of the pillbox marksdwarves that run out of ammo have never attempted to path to melee.
Do we know where the limit is on this?  In my case theyd have to go down 2 z's, maybe 30 along the x axis then up 2 and path another 60-100 through a trap corridor...but they never do.

So this was my first try but it does have a few limitations.

Spoiler (click to show/hide)

1)
The up/down stair leads up to a fortified roof.  This was nice for when some of my marksdwarves didnt have targets as setting
a station order on the roof caused any not firing to troop up there where they got new lines of sight.

With my FD mod however I suffer from flying mounts a lot.

2)
Elite ranged units will annihilate your marksdwarves through the fortifications,
especially so in seige situations where your snipers got lots of closer targets and the elites can sit untouched and drill your boys
(since they stopped advancing the moment they got range their melee moves up and covers them...bad situation)

3)
Reloading of marksdwarves is entirely unsatisfactory.

Thanks to Psieye's thread on reloading http://www.bay12forums.com/smf/index.php?topic=85688.0 I got some ideas for improvements to my second generation of pillbox designs
The general point I took from that thread is that marksdwarves wont reload if they have Line Of Sight to an enemy.

[celem]

Version 0.2

So I wanted to improve this design and try to remove as many weaknesses as possible.

First up I happened to read http://www.bay12forums.com/smf/index.php?topic=79133.0 by Girlinhat and loved the idea.
I built 8 of these animal watchtowers scattered around the pillboxes at approximately maximum X-Bow range.  The results have been very pleasing with 80-90% of ambushes decloaking at max range from the pillbox,
this results in them usually breaking and/or dying before the trap corridors which simplifies my seige cleanups massively.
Along the same vein of animal watchpower I also assigned animal training to my marksdwarves and had them create some hunting dogs that idle in their barracks while they train.
Net result...nothing has ever since reached the gate in stealth and most stuff becomes visible the moment it enters my map

So with detection out of the way lets look at the weaknesses I identified in the first design.
1) the roof.  This was an easy fix as I elected to lose the ability to move non-firing dwarves to the roof in favor of protection vs fliers.
Usual fix, scaffolding stairs outside and cap the holes,  NB: Remember that fliers can path diagonaly on the vertical axis, you need to build a floor directly over fortifications to make them secure.

2) The enemy elite ranged units were bugging me.  My tactic was always to scope the invaders when they spawned and should they include elite ranged units i'd send my marksdwarves to the magma forges on a station order
(the only time I ever issue an order to them with the military controls)
This was not satisfactory as they are standing around being useless then.

3) In big seiges my marksdwarves are usually out of bolts after the first 3-4 squads have passed them (FD often gives you 10-12 enemy squads on the map at a time)
Because they still have LOS to the hostiles they dont reload but stand and glower at them instead.  This is dumb.
So, how do we fix problems 2 and 3?

Introducing v0.2:

z-0
          bbbbbbbbb
          bbbbbbbbb
        bbFFFFFFFbb
        bbFa       Fbb
        bbF FFF   Fbb
        bbF       dFbb
        bbFFFFFFFbb
         bbbbbbbbb
         bbbbbbbbb

F-Fortification
a-Armour Stand
d- down stair
b-bridge

Hopefully you can see whats going on here.  I replaced the up/down stair with down and capped the roof.
Next I built 4 raising bridges in a square around the pillbox, each raises inwards towards the fortified wall it touches.
The net result is that when you hook all 4 to a lever you can activate/deactivate your pillbox remotely.

If you pull the lever, the bridges raise and LOS (if present) is broken.  Marksdwarves inside are invulnerable (only entrance from below).
I use this lever for when elite ranged enemies arrive, as they approach the pillboxes I just pull the lever and the snipers get protected.
Since they lose their targets they fall back on orders, i dont issue any so they follow the schedule, which is set to always train where they already are.
Result of this is that my marksdwarves only ever move to eat/drink/sleep or to move back and forth between the barracks/range pillboxes (via ammo piles)

The other advantage to these bridges is a little hidden and somewhat less reliable though I've been experiencing good results.
If your marksdwarves are engaged when you seal their pillbox and have already expended their ammunition then breaking their LOS to target tends to cause them to asses their ammo and immediately reload.
With the design above the reload is all of 5-10 steps there and back.  Once they start to return from reloading you pull the lever again and fun resumes.

Marksdwarves that reload when you pull a lever.  Fun right?

Ideas, comments, criticisms? Im still evolving these designs

Weaknesses that remain:
Dragonfire (and hellfire imps in FD) can destroy raised bridges, even those that are magma safe
There is still technically this path from inside to outside, I hope they never get it into their heads to try and move to melee

Picture

Spoiler (click to show/hide)

Ok so theres still an up stair, this is a different fort to the one I developed it on and here I kept the fortified gallery above and capped that to prevent fliers, best of both worlds.

[celem]

I decided to sacrifice one of the shorter firing walls on my range and build an arrow return.


FFFFFFWWW
      AF    . W
FFF   F    . W
      AF    . W
FFFFFFWWW

This is the right hand side of the range pillbox which faces a river.
The A's are the targets, I built a retaining wall (with roof not shown) and channeled a trench shown by period's '.'
Arrows that miss the target fall through the channel, there is an ammo pile beneath, just unforbid and they're quantum piled for you.

[Pan]

Good stuff, my good man. Good stuff indeed. Will be incorporating some of this in me next fortress. Actually, why wait?

[Triaxx2]

I use a modified Dwarf Box approach for a multi-level shooter tower.

Code: [Select]

FFFFFFFFFFFF
F                F
F      AAA       F
F    AWWWA  F
F    AWXD     F
F    AWWWA  F
F      AAA       F
F                F
FFFFFFFFFFFF
The center is all wall with a door, while the outside is all Fortifications. Archery targets on the insides, so that they can simply shoot inwards then turn around and pincushion anything approaching from the outside. Since the inside wall is solid, they can change levels without suddenly getting distracted by enemies. And it's possible to reach the top level, which is solid walled during sieges. The top contains a dining room and food storage, so the inner walls are important for haulers to keep moving food and booze around.

[Fredd]

Use the move order, order them to move to same area they are standing. Move order makes dwarves reequip fast. So if they are out of arrows, should go get some. But once on the spot, and fire off all the bolts, may have to cancel move order, then repeat above

[Crazy Cow]

My pillbox designs are very, very simple. I use squads of 3-5 dorfs in each of my squads, and by pillboxes usually look like this:

Code: [Select]

FFFFF
F>..F
F.W.F
F...F
FFFFF

Naturally, constructed walls form the roof. I build them into walls if I can, removing sides and, therefore, vulnerability. However, the addition of an armor stand is a simple and brilliant idea. Thank you, and I will install it immediately.

EDIT:
I just read the whole thing through, having skimmed it the first time. You have put a lot of thought into maximizing the efficiency of fortifications.

[GhostDwemer]

Ah, celem, have you tested the behavior of arrow returns in .25? I had a range set up just as you describe, storage piles and all, and after the first time I unforbid all those bolts, I quickly forbid them again and floored over the channels. Every idle dwarf in my fortress poured into that arrow return channel, picked up a single bolt, and took it to a different ammo storage pile.

[celem]

Thats unusual.  The first design was implemented in .21  I've transfered it across to my .25 fort now.  I'll see if I can find out whats going on with the quantum return.


EDIT:

Ok, I've got it working somewhat in my .25 fort.  It seems it hasnt been working as I thought:

The reason my dwarves are'nt dragging the reclaimed bolts all over the fort is that the stockpile they land on is the only ammo pile with space.  It isnt set to take from the pile by my forges...I just let produced bolts overflow to the pillbox piles.  When I unforbid the bolts I thought they just sat there, this is becuase I have few idlers.  In fact they are slowly being added to the bins in the pile beneath them before being claimed by snipers.

Restricting yourself in ammo piles to get this trick to work somewhat isnt such a problem as it might be...after all the point of these pillbox designs was to make your marksdwarves more efficient, why not get the meta-layout in order too?

My pillboxes ring my fort, only 2 are fulltime barracks and one is a range.  The other 4 contain animals most of the time.  Each also still contains armour stand and repositioning marksdwarves is as simple as moving the squad from one armour stand to another (you then need to flip their alert off and on again to interrupt current training tasks).  These defenses form a ring with fort and range in the centre, all are connected by a spoked wheel pattern of tunnels on z-1, at the hub of which is the bolt return, ammo pile and melee barracks.  This lets you get melee into a pillbox should it ever be needed, and should the enemy enter one their path then leads to melee barracks.  Each pillbox has a 1-tile ammo pile directly beneath it set to fill from the main one at the hub, this way they always have close ammo and the archery range bolts wont get dragged back to these.

Stuff all gets kinda complex the more you try to optimize, but most of the things im describing in this thread can easily be implemented with varying success individually.

[khearn]

I don't think you can have multiple stockpiles all pulling from one. You can have one pulling from many, or a chain where #5 pulls from #4, which pulls from #3, etc. But a chain means a lot of hauling from one pile to the next to get an item from the head to the tail. I think it's actually implemented as a push, rather than a pull. An item is in a stockpile and the code says "can this be sent somewhere else?" and if there were more than one places to send, it would get confused. I supposed it could be done if there is an ordered list and it just sends to the first non-full pile on the list, but it doesn't seem to be done that way. It's a shame, because having multiple distributed piles pulling from a central pile would be very useful in many situations (booze and food come to mind).

I like the idea of having the bridges to cut off LOS, but you might want to have each controlled individually. That way if the enemy elite bowman is south of your pillbox, but there are other targets in other directions, you can drop those bridges and engage the safe targets. Of course, you'll have to keep a close eye on things in case the elite moves, and there is always a random delay in getting a lever pulled and then the delay before the bridge moves, so it would be more risk fun.

Are your pillboxes on ground level, or elevated one level? On ground level would mean that enemy non-elite archers that get next to the fortifications can fire in. Of course, the bridges would give one a way to deal with that.

[Corneria]

Have you tried filling one of these with tamed dragons?

[Triaxx2]

No, sorry, that's supposed to be X=Stairs D=Door. Totally unintentional.

[Sadrice]

You could build a special purpose forge for bolts and just let them stack up there.  Retrieve fired bolts by periodically forbidding the bolts in the forge and creating another bolt stockpile, undesignating it when they finish hauling.

[celem]

Thats a pretty good idea actually, gonna try and see if you can build up a good stock like that without cluttering the forge to death.

[Arkenstone]

The building isn't the source of your problem here, it's lack of combat tactics (for example, you assume 360 LoS is a good thing).  Just sitting in a tower in the middle of nowhere leaves yourself exposed to the enemy firebase (their elite marksmen) while you're tied up shooting their advancing forces.  You need to look up modern military tactics with overlapping fields of fire, and also forcing the marksmen to close with you before they can shoot.  I'd explain more but I got to go right now.

PS: try putting an ammo stockpile in an "airlock" or two below the tower, and whenever you have a siege make sure some dwarves have all tasks but ammo hauling turned off.