Dousing ship fires is indeed abstracted in the game. It is not covered by the ship repair routines but has its own set of routines. Relevant considerations for fire fighting are as follows.
1. A ship on fire in a task force with other undamaged ships will receive some help in dousing the fires from the other undamaged ships in the TF.
2. High system damage limits the fire fighting ability of the ship's crew.
3. In a port the normal fire fighting routine is based on:
(a) port size (less port damage). The bigger the port, the greater the fire fighting assistance
(b) naval support. Again the more present, the greater the assistance
(c) ship crew experience
(d) the level of ship system damage. A ship's systems abstracts the presence of fire fighting equipment such as fire hoses
(e) luck, aka die rolls
4. With the exception of point 6 below, all ship fire fighting occurs outside of shipyards or offline in pierside/tender repair modes. This means that shipyards/pierside/tenders provide no assistance to combat ship fires and a ship already on fire cannot be placed in those facilities.
5. A ship's flotation damage also plays a role. At a certain level (undisclosed), of flotation damage, fire fighting efforts degrade. This level varies depending on whether the ship on fire is
(a) at sea alone,
(b) in a small or big port
6. A ship which is already in a shipyard and whilst there a fire starts, as of patch #2, will remain in the shipyard for a single turn. If the fire is doused completely (together with the additional damage caused directly by the fire) in that single turn, the ship will resume its previous repair work on the following turn. All that is lost is a single turn's repair work as all attention was directed towards dousing the fire. However, if the fire is not completely doused (together with the additional direct damage) in that single turn, the ship is automatically moved out of the shipyard and cannot be returned to the shipyard until the fire is extinguished.
It is a very rare occurrence for a fire to start in a ship in drydock. This will usually only occur if one of the rare catastrophic events occur, or the enemy bombs the port and inflicts port damage.
Don Bowen was the main dev who commented on fire fighting, mainly in 2009 but also in 2011. I'll edit this post to provide the single most comprehensive thread on the subject.
Edit: As promised this is the single best thread but there are several others which include posts from Don Bowen.
< Message edited by Lowpe -- 2/16/2021 2:04:06 PM >