Felling trees "something has collapsed on the surface"

[ace2819]

Hey all.
I've been running into trees "collapsing" and killing/injuring my woodcutters with some regularity. Has anyone else seen a major uptick in this? I played classic extensively and never had this happen.
I actually think that could be an interesting feature, but right now it feels a bit too random to be intentional.

On the bright side, my last casualty was a "talented" woodcutter, but was also a newly minted baroness who just imposed an export mandate bc she didn't like her bedroom. Let the elves have the corpse.

Cheers

[ptor]

Same happened to me: my first guess is because that biome is a dense forest and I've been chopping trees that are next to each other, felled tree A triggered the collapse of some of tree B's "compenetrating/leaning on" branches?

[[MadTs] Phyrys]

Did you saw some fire-related apocalypse outside ? Burnt trees stops being considered as trees and collapse when they're chopped.

[[MadTs] Phyrys]

To explain how I got here, spoilers spoilers :

This ♥♥♥♥ here :

https://cdn.discordapp.com/attachments/402978055087325184/1050820461921050665/SPOILER_output.png

Came to pay a visit. No, it's not an ugly mf, it had a REGAL BEARING. Also it could breathe fire all day long and took offense of my militia trying to vivisect it (it made a point on one of them not knowing how to use his shield), shortly before getting impaled by them.

Now, half the trees outside must be felled by armored dwarves. I'm considering enlisting all my woodworkers to the army and giving a full steel set to minimize casualties.

[BaconFase]

If you fell a tree and have already dug out its roots by digging below it then it will cause the surface floor to collapse and fall below; you will have a hole where the tree used to be.

[I LOSE MID LANE]

Felling trees from my experience has the logs from the trees fall forward, these logs aren't lethal. HOWEVER logs can fall into other trees. logs that have fallen into other trees are lethal if you chop the tree down that's holding them.

Therefore best way to avoid losing wood cutter dwarves is by cutting from farthest to closest rather than closest to farthest, then once you get like 2-3 more woodcutters and a hospital you can kinda freely fling them into nature and hope for their best health honestly.

ive also noticed it happens more frequently if you have a lot of trees in your area.

[Malkyne]

I've played DF for years, and I agree that this is happening abnormally often. I will attempt to address this in a thoroughly dwarfy way. If the trees intend to do battle, then we shall armor our woodcutters, and train them for war!

[Squ'ith Shapeshifter]

I'm thoroughly convinced this is an issue with trees growing INTO each other.

I've spent a few days meticulously removing timber that has become lodged in branches, and these surface "cave-in" events continue unabated.

But I've isolated a save where the branches of pear tree appear to have directly intersected with the trunk of a pine. Chopping down the pear tree BEFORE THE PINE TREE triggers an explosion that immediately kills the woodcutter, and destroys every Z-level of the pine tree above where the two trees intersect.

I theorise that the upper-layers of the pine-tree have become dependant on the branches of the pear tree for "structural support". Cutting down the pear tree removes those branches, and the game thinks that there's nothing supporting the 4-or-so Z levels of the pine tree, causing these upper layers to collapse in a spectacular explosion.

Cutting these two trees in reverse order yields no cave-in/explosion.

[kheftel]

Originally posted by Glowshadow:

I'm thoroughly convinced this is an issue with trees growing INTO each other.

I've spent a few days meticulously removing timber that has become lodged in branches, and these surface "cave-in" events continue unabated.

But I've isolated a save where the branches of pear tree appear to have directly intersected with the trunk of a pine. Chopping down the pear tree BEFORE THE PINE TREE triggers an explosion that immediately kills the woodcutter, and destroys every Z-level of the pine tree above where the two trees intersect.

I theorise that the upper-layers of the pine-tree have become dependant on the branches of the pear tree for "structural support". Cutting down the pear tree removes those branches, and the game thinks that there's nothing supporting the 4-or-so Z levels of the pine tree, causing these upper layers to collapse in a spectacular explosion.

Cutting these two trees in reverse order yields no cave-in/explosion.

Wow, nice experimentation! That explanation makes sense to me.

[Alexspeed]

I am not sure what is going on, but i have the same situation here.

- Playing the Tutorial. (my very first game with the steam version)
- Happened 2 times "Something has collapsed on the surface!" in a very short time (2 minutes at most).
- 2 dead dwarfs, both assigned to cutting trees, both badly crushed to death.
- All the trees i specified for cutting where right next to each other (I wanted to cut one and leave the other one standing)
- No holes in the ground anywhere near where it happened.

- One of the dead dwarfs was found by his child daughter, which is now probably traumatized for life.
- I still have to learn how to make graves and bury them *sigh*


Something weird is going on here.
I don't know what exactly is wrong, but the Theory of Glowshadow above seems possible.

If this is a bug, I hope it gets fixed.

[Squ'ith Shapeshifter]

From my (altogether limited) experience, this issue sounds like it may be more prevalent on tutorial embarks. The tutorial will actually only start if you have an embark location with very specific prerequisites. I *suspect* (but don't *know*) that one of those prerequisites may include having a very lush forest, which new players definitely *should* be given access to (at least in theory) in order to jump-start their lumber industry. However, if the trees are too close together, you're unfortunately more likely to experience these cave-ins.

One thing to note, is that the presence of incredibly tall, straight trees (such as pines, coconut, and date species) appear to be the ones more consistently prone to cause dwarf fatalities, at least during my own experimentation. If a nearby tree intersects with the trunk of a pine tree that is 4-5 Z-levels tall, the cave-in explosion appears to be more severe. That's four stories of lumber crashing directly down into the square directly below, after all! This particular scenario has consistently proven fatal for not only my dwarf woodcutter, but anyone else within a certain blast radius as well... But pine trees in particular don't branch out much, and as such, are very unlikely to grow out into other trees.

So, my advice? If you really MUST cut trees that appear to be growing directly adjacent to each other, cut the pines FIRST. Since the pines are highly unlikely to grow out and start to provide structural support to OTHER adjacent trees, they (probably) won't cause a cave-in when they're cut... Provided that they are the FIRST tree in an intersected-tree-pair to be felled. Cutting these trees in the "correct" order has consistently proven to neutralise the existential threat, in my experience.

If you've got trees that branch out at a lower level, (persimmons/willows/pears) these will cause more consistent cave-in alerts when you're clear-cutting a section of forest. But because they rarely have more than a few Z-levels of growth, the cave-in effects they produce will only rarely do anything more than stun the dwarf that felled the offending tree pair.

The true danger appears to lie in biomes where you've got tall, straight trees, growing next to trees that branch out at very low Z-levels. If you've only got one or the other, your lumberjacks have nothing to worry about (aside from roving bands of goblins).

[Morkonan]

Originally posted by ace2819:

Hey all.
I've been running into trees "collapsing" and killing/injuring my woodcutters with some regularity. Has anyone else seen a major uptick in this? I played classic extensively and never had this happen.
I actually think that could be an interesting feature, but right now it feels a bit too random to be intentional.

On the bright side, my last casualty was a "talented" woodcutter, but was also a newly minted baroness who just imposed an export mandate bc she didn't like her bedroom. Let the elves have the corpse.

Cheers

AFAIK, the cause is there's a tree being felled that hits a nearby tree.

When cut, a tree only falls in one of the four cardinal directions. BUT, it or its branches can hit another tree on the way down and that will cause that other tree to collapse.

So, be careful letting woodcutters cut trees in crowded stands of trees.

[Old Man Jenkins]

Originally posted by Glowshadow:

I *suspect* (but don't *know*) that one of those prerequisites may include having a very lush forest, which new players definitely *should* be given access to (at least in theory) in order to jump-start their lumber industry.

The prompt asking if you want to play the tutorial says "Would you like your fortress located in a forested mineral-rich riegon of this world where you can play through a short tutorial?" so you're spot-on in that respect. In my first fort 2 of my dwarves died to a falling tree and I didn't want to try to struggle on with 5 so I retired it.

I've had a lot of trees collapse since but I've always started with the tutorial because I'm a perfectionist, and really focused on design. I got one fort up to like 80 of the little buggers but they were getting mad so I'm starting again, and I already had to reload the autosave and replay the tutorial because as soon as it was over a tree collapsed and killed a dwarf.

This time I'm going to focus on: a) spacing out my logging and b) taking it slower so I end up with nicer halls and happier dwarves that aren't feeling like I'm working them to death.

[Holyvision]

Originally posted by Malkyne:

I've played DF for years, and I agree that this is happening abnormally often. I will attempt to address this in a thoroughly dwarfy way. If the trees intend to do battle, then we shall armor our woodcutters, and train them for war!

Pumpjack lava to the surface and just go full scorched earth.

[Helios]

Some tree are only 1 block on surface but if the become realy old they also get extra blocks spreading over the place and it colapse if the central trunk is missing ginko and highwood trees are save in my biome because the block on surface also grows.

[pezenwever]

My first lumberjack died felling his first tree in the tutorial :D
Since that fort I did not have anymore fatalities just because I do not chop trees next to water or the borderline. Chopping 2 trees next to eachother gives no issues and I killed over a thousand trees. Did you hear that longears ?!