Metal Trussing Bridge Breaks!!??

[Tr1ggi]

Hi folks,
Building a bridgeway over some pillars with Metal Trussings, I'm facing a problem:
Of course I understand the way gravity and weight of objects works in this game and I know how far I can build a bridge before in breaks but, sometimes already the third or fourth Trussing breaks/falls down.
Somtimes when I walk over it, sometimes on its own and I don't know why...

Anyone faced that problem?

[Ashtaroph]

Is your bridge just trusses butted face to face? If so thats why they wont hold up, bridges need either guy ropes to support them or a bridge with a curve in it, think pyramid, each block supports the next block

[Mytheos]

Are you building onto a prefab? If so that causes random weirdness.

Its been awhile but its around 7-8 blocks before your weight takes it down...should be able to hit 14-15 before its own weight takes it down...

And I think if you have multiple rows you can hit the max 16.

( I think its like 4 rows needed for 16 )

[Tr1ggi]

Thanks for the quick respond! :)

@ Ashtaroph:
The bridgeway is pretty simple just plane trusses on pillars connected to eachother in a straight way. It looks like this:
____________________
|............|.............|............| ... I think you got the point.

@ Mytheos:
I don't quite know exactely what you mean by prefab (needed to translate it in german) but I build them completely free/mid-air/off the ground (as you see some lines above).
The gap between the pillars is about 14-16 blocks. Starting to connect them from both pillar-sides they need to take the weight of 7-8 trusses.


For 90% of the bridge it worked just fine but only on the last gap... tha last blocks won't hold up. The gap is even smaller than the other ones.

[Mytheos]

Prefab = Prefabricated, or the houses and buildings that already exist in the game.

But as you have explained what you are doing in more detail that isnt the case.


Try putting your pillars closer...the MAXIMUM distance you can span with blocks = 15/16 or whatever it is this version


http://7daystodie.gamepedia.com/Structural_Integrity

( Metal Trussing Structural Integrity = 16 )

Structural Integrity describes how many blocks of one material can be used to build an unsupported structure.
One example for such a structure is a horizontal beam. It is important that the player uses the same block for the base as for the beam itself.
There are some limitations to this.

It is not possible to build a beam longer than 15 blocks. The 16th block simply drops and doesn't stick to the beam. It is unknown if this is a bug or intended.
A beam longer than eight blocks will partially collapse when stepped on the 9th block.

[Sigh-Phi-Guy]

OP: you must start your bridge from land with at least 2 blocks on top of the land before you start to span over the water. DO NOT attach your blocks to the side of a cliff face! place pillars with 8 voxels between them and you should be fine. just dont try to span from 1 pillar to the next. you go halfway from 1 pillar then halfway from the next pillar and connect them. your bridge surface must lay ON TOP of the pillars if they are different materials.
also the higher you go the harder it is get blocks to hold.
rebar has terrific structural integrity. brick pavers do not. if you come off of brick pavers with rebar, the rebar will inherit the structural integrity of the pavers and fail quicker.

[Tr1ggi]

Thanks a lot for all your information!

Indeed I'm already aware of most of it. :)

In fact, my bridge is not a common one over, say, a river. It is more of an overpass with multiple pillars. It does not reach over more than 15 blocks and the surface lays on top of the pillars. Which means that the connection points are also made of metal trusses.
I'll go ahed and try to get a good screenshot of it to link in here.

[Operation40]

i don't ever span more than 6.. i know, probably overkill.. but I get so damn frustrated when my stuff falls.. lol

[Tr1ggi]

Good point though, Operation40 :)

I hope these links work, if not you can look them up at my profile:
Screenshot1
Screenshot2

The missing trusses are those who fall down all the time. Some from their own weight, some when I walk over it.

[Sigh-Phi-Guy]

tricky...
i just built a somewhat similar covered wooden bridge. 38 voxels long, about 10 high with 1 voxel pillars every 10 voxels(8 between) that angle into a "Y" and 7 voxels wide. the floor is naked rebar frames topped with log cabin wood.
http://steamcommunity.com/profiles/76561198107909924/screenshots/
i didnt have any issues.
my thoughts...
do you have a mine or rooms anywhere beneath the area that keeps falling? empty voxels below can mess with integrity even if they are at bedrock. its the only real thing i can think of as the rest of it seems to be staying up just fine.

[Lerch Addams]

Same thoughts as sight-phi-guy.

If you are not exceeding 14 block limit for Metal Truss then the only other failure mode would if you have a tunnel or mine underneath those spans.

http://steamcommunity.com/sharedfiles/filedetails/?id=377486890

This bridge uses Metal Truss covered with Concrete Ramps and spans up to 14 units stable.

Also if you've had a mine collapse underneath that bridge, it may cause the same behavior.
The best solution is to try to backfill the collapsed tunnel or mine as best you can.

[Tr1ggi]

Well sigh-phi,
at first thanks for your help, that might really be the issue. I got large mine at bedrock level under my whole area. Well, then... so be it! ^^

Secound: what amazing and impressive constructions you build! Awsome!
Du you build most of your stuff with frames? If so - why?
AND... (sorry for beeing so snoopy) I've seen you build metal-reinforced wood log spike -> How? :)