@PwnedByDumplings supercapacitor's "recharge speed" setting(hidden in middle of turret, behind deco plate), higher speed = faster cooldown and harder to overheat(from some high point impossible to overheat). Also "capacity" also affect, higher capacity = higher overheat threshold and longer cooldown.

what setting do i adjust to lower the overheat time?

@Kaiser strange, at my side all seems to work as intended.. idk, it may be just about balance preferences. As it is just stuff for sub editor, you always can change and adapt it for any your purpose. If you dont like "overheating" and "cooldown" time, just experiment a bit with settings of batteries(they hidden behind round part in middle of turret) and gun's power consumption

It very easy to overheating now and cool down was very slow

@dingjunhuang.health maybe it happens because "overheating" mechanism uses hidden shuttle batteries with huge stored amount of power which, as i thought, will be enough for any adequate amount of time played on one submarine. And it simply wasn't enough. I multiplied amount of stored power by ~100 times now as potentional fix of this problem.
How long you played on sub with it to find this problem?

It's very useful. Also, I have installed four chaingun turrets outside my submarine. But, however, after playing for a period of time, only one of them is workable, and the others are kept in overheating. How should I repair this problem? Thanks.

@Garother Roger that, thank you kindly :) "same as the planters" I was referring at the planter boxes for the plants, who are positionated with E key

@Ewk95 don't sure what you mean at "same way of the planters" (seems my english skills fails here), but as it is item assembly, the only way to add it to your sub is through submarine editor.

Can I place the turrets in the same way of the planters or it's required to add them in the editor?

Jesus Christ what witchcraft is this?

This could go along well with the yota t100 sub

@Goth Loli original idea of for what is this was made - heavy fire platform that can be easily accessed from outside of submarine when salvaging or mining, or in other situations when submarine stay still or move slowly. In other words, the original idea didn't include situations of using it when submarine moves at normal speed.
But if you for some reason want to use it when sub moves.. One option you named - small exterior hulls, which is not a big problem only for large subs. Maybe also it is possible to place some walls without hull somehow that will try to prevent pulling away from turret, but it likely to be very unstable, if helps at all. And there is always option to just make small room with hull, pump and door that simply can be accessed only from outside.
I don't see here any other potential solutions of it.

That's what I get for skimming through the description.

@Majectic Blue Falcon um, I guess you misunderstood what is this workshop item.
This is NOT a mod, this is item assembly - set of items that you can copy-paste to your submarine when you build/edit it. I.e. once you copy it to your submarine, you not even need to be subscribed on this to have it working. "Overheating" actually is made from hidden logic parts and a bit of exploiting some game mechanics.

I like the idea of overheating but I don't like the lack of a power source. Could you add a new type of battery that only fits these turrets. Make it a large item that can only be carried by hand or with a scooter. Let the batteries be plugged into a sub battery or charging dock and give them different quality levels.

I'm doing this with another ship of my own and I had to place exterior hulls covering the periscope; otherwise, you'll end up getting pulled off the gun the moment the ship moves. This can be problematic because these hulls are seen as interior rooms and they will sink your submarine like a ballast. On a small submarine, it's a pretty serious handicap. If you find a solution to this issue yourself, I'd like to hear it.

Insane!

same we need creativity like this more often

Great idea!