Okay Ive seen a bunch of posts where people claim that GCS, and web spinning forgotten beasts need to be able to path to targets to be able to spit web, and if thats the case then they must be able to path through either:
A) Raised bridges and forbidden doors
or B) Fortifications
Both of which people claim is impossible...
But my spider farm works fine (currently all I have is a web breathing forgotten beast but it works just as well for GCS' when I get them)
Now because I had to time raising drawbridges to capture this beast there is a corridor that he can run up and down while breathing webs, not an issue and if you have a cage you can always remove the corridor for a 1x1 room.
The layout:
#=wall
B=Corridor the beast can walk across while spitting webs
F=fortification
G=sight blocking raising bridge
R=retractable bridge
H=floor
V=chain
D=door
###########
#BBBBBBBBBBB#
#FFFFFFFFFFFFFF#
#GGGGGGGGGG#
#RRRRHVHRRRR#
#RRRRHHHRRRR#
#RRRRRRRRRRR#
#RRRRRRRRRRR#
#####D#####
Here is what it looks like with comments to explain it:
Heres the image without all the cluster of comments:
After enough web has covered the bridges you simply queue 4 'pull lever' orders and it will dump all the silk below (you dont need to pull it 4 times, I just find thats easier as it will only have enough time for the bridges to retract and then deploy again, so you dont have to order it a second time). Have a chanelled out room below it and there you go! Infinite silk!
Here is an example of the silk output: