Repair times (and costs)

[BathTubAdmiral]

I really wonder how repair times are calculated (and repair costs, as those are the product of increased monthly maintenance and repair time - see blur: Repair Costs as well).

I can't really make sense of what the game gives me - check the attached PDF (RepairSpeeds01.pdf (23.78 KB)).

It seems CL are vastly faster repaired than DDs, to the point that CL Mainz which had "30%" damage (dam.pts. vs. tonnage), most of it engine damage, is instantly (and without cost?) repaired, while I have to pay and wait for the repairs on the barely scratched DD Z117 and DD Z127 for a month.

[wlbjork]

Difficult to know as this is quite clearly "hidden under the hood".

Presumably, Mainz suffered from a "silver BB" (maybe only bronze) - that is, the shell came in and took out critical propulsion components that are easily replaced in a dockyard setting, but not a major component(such as a boiler).

Thetis on the other hand - despite requiring a complete superstructure rebuild - is also going to be repaired suspiciously quickly.

Further investigation would seem necessary - perhaps a check of each hit in the log in future battles?

[dorn]

I would expect there is quite a random as it would fit into simplification of repairing and statistical or expected result. And on top of it there are several factors that can change the probability function.

[oldpop2000]

In the real world, the Chief Engineer and the Engineering officer will do a complete estimate of damages and parts needed to repair. This report will be transmitted to the fleet headquarters. They will assess the requirements and in turn, locate a local yard or navy yard that can perform the repairs. If it is hull damage, then the yard must have a dry dock capable of pulling the vessel out of the water and cranes large enough to remove damaged parts and install new ones.

After the ship has arrived at the yard, it might have to dock, and wait for the available dry dock. The repairs might begin before that occurs. After that, the ship is pulled into the dry dock and then a complete assessment of the hull damage, parts necessary and estimated time of repairs. All this will be contingent on parts availability, worker availability and fleet requirements. As the ship is undergoing repairs, many times new problems are found. Sometimes the fleet decides to include upgrades and updates at the same time, which will again, lengthen the time necessary to complete the job. After the repairs, the ship is refloated, then sent to the outfitting dock and then the ship will proceed to sea for sea trials. After that, she will revictual, refuel and head to the war zone. 

The lack of available shipyards to perform the work and location can hamper repair times. The Japanese had this issue. They had to use their shipyards both private and naval to finish building new ships while ships might be awaiting war damage. Repair ships are very handy to perform temporary repairs to keep the ship in combat. The British private shipyards were moved to the Clyde as the Naval shipyards were not large enough to build wider ships. German had the same issue. The US problem in the Pacific was that Pearl Harbor's naval shipyard had not been finished by the start of the war. After the attack, most ships had to head to the West Coast. It was only around early in 1942 that the yard became fully operational and the ships could stay in Oahu for repairs.

From an official naval document on repairs 

During World War II, when a ship sustained battle damage or any other type of mishap occurred (e.g., collision, running aground, explosion, fire, heavy weather damage), a War Damage Report was required. At the first opportunity, a follow-up, detailed, preliminary shipboard inspection/damage assessment at sea of the affected space(s) was conducted for a required, descriptive War Damage Report. This report was to be signed by those officers performing the inspection assessment and the commanding officer. The requirement was to report date, time, and location or area of operations; personnel casualties (name, rate/rank, branch, and service number); a brief description of damage; and mission impact. If the complete damage analysis assessment could not be conducted and completed at sea while underway, a more detailed inspection would had to be conducted at anchor in a safe harbor or in port.

On smaller ships (e.g., DDs, DDEs, LPAs, AOs, ARSs, AEs, LSDs, LSTs), the formal inspection was conducted by the Assistant Damage Control Officer (ADCO/DCA) (1st Lieutenant), Chief Engineer and Executive Officer. The appropriate department heads - deck, medical, gunnery/weapons, supply and operations - were required to assist in the inspection of damaged spaces under their cognizance to provide systems data descriptions/mission impact for the report. The inspection team was assisted by two yeomen and one photographer, who would create the report in accordance with existing fleet instructions. In some cases, where the ship remained operational after sustaining damage, flag staffs would embark in ships in their squadron to conduct the War Damage Report Inspection Assessment, as smaller ship's crews were overwhelmed with the tempo of operations and maintaining the ship at sea. In those cases, every hour was crucial to those crewmembers after battle damage. If a significant number of the crew had been lost, remaining crewmembers were needed for standing watches - there was no one else qualified (or who could qualify) to steam the plant - and preparing the ship for another possible encounter with the enemy. The threat was continuous, as long as the ship remained in the War Zone of Naval Operations in WWII.

On larger ships such as Flag Ships (e.g., BBs, CVs, CAs, and CVEs), this formal inspection was conducted by embarked staff officers. These officers were assisted as required by the ship's company, including the ADCO/DCA (1st Lieutenant), Chief Engineer and Executive officer, and appropriate department heads, such as air, deck, medical, gunnery/weapons, supply, communications and operations. The inspection team was assisted by three or four yeoman and two photographers, who would create the report in accordance with existing fleet instructions.



The results of formal inspections were submitted immediately by a top-priority, classified message to the Navy Department for immediate review, Fleet Readiness Assessment, and appropriate actions, with a serial number assigned and dated. Distribution was according to existing directives and filing.

[wlbjork]

In real life, yes. In the game...no. Graving docks aren't tracked, so all ships are able to be repaired no matter what the damage is.

Likewise, there's no extensive repair requirements (I've yet to see an ship sent to the dockyards for more than 4 months) which precludes the extensive rebuilds that have occurred in such an event.

[oldpop2000]

Nov 22, 2019 10:22:26 GMT -6 wlbjork said:

In real life, yes. In the game...no. Graving docks aren't tracked, so all ships are able to be repaired no matter what the damage is.

Likewise, there's no extensive repair requirements (I've yet to see an ship sent to the dockyards for more than 4 months) which precludes the extensive rebuilds that have occurred in such an event.

Well, by putting real historical information out, maybe the team can modify the program to reflect the damage and repair times. I don't know, just speculating. If the average repair time is no more than 4 months, that is not entirely accurate. The battleships lost at Pearl Harbor took two years for repairs and modifications. Maybe that should be the change, if the ship is just in for repairs then that is one value, but if it tells you that you could include modifications and upgrades, then you can make those changes and the times will change with them. I think that would be a good modification of the program.

[dsilva44]

This would actually be a very good idea if put into use. The normal popup about a ship being damaged could be replaced with one that informs you that ship xx has been damaged by a mine (or torpedo, or whatever) and can be either repaired for this time and cost, or can be rebuilt (prompting the redesign window to pop during the turn, like when you are told that a design is ready and you choose to modify it). This would add a more dynamic response to ships which are damaged in battles or as a result of the game's tun damage mechanic that could add more realism and variety to the game in each playthrough.

[oldpop2000]

Nov 22, 2019 12:39:48 GMT -6 dsilva44 said:

This would actually be a very good idea if put into use. The normal popup about a ship being damaged could be replaced with one that informs you that ship xx has been damaged by a mine (or torpedo, or whatever) and can be either repaired for this time and cost, or can be rebuilt (prompting the redesign window to pop during the turn, like when you are told that a design is ready and you choose to modify it). This would add a more dynamic response to ships which are damaged in battles or as a result of the game's tun damage mechanic that could add more realism and variety to the game in each playthrough.

The issue is would it put far more detailed work into the game. Maybe a check box for the detail to allow us to choose  or not, to do it. Many upgrades like installation of radars, and other fire control functions could be done with repair ships or on the docks where the ship is berthed. I will leave this point to the team. Just an idea.

[avimimus]

It'd be really nice if there was an option where repair times were much longer (2-3 times longer)... It would make the wounding of a ship matter.

[akosjaccik]

While I'd not like to address the exact numbers either way, I'd still like to point out a factor in the game that perhaps does not get enough attention and things sometimes suffer because of it - and that would be game size. For example, to my knowledge (which might be dated by this point, but there is a fair chance for it being correct) hard-coded airfield sizes, among other things, do not scale with game or fleet size, resulting in "Small", "Medium" or "Very Large" campaign players equally having to deal with 120 a/c airfields built up in every village by the AI.
Maintenance time can be one of these unequalizing factors, as IF the events regarding that do not scale (for example, if for one reason or another there is no significant difference in the players' capital ships getting torpedoed by subs), then the "Small" player might have to make do without 10-40% of his main forces, whereas a "Very Large" (or above that, as on Discord modding fleet size is relatively common) player might not care about a couple extra months at all.
Once again, without hinting at actual numbers or anything - I just wanted to point out that there are other, interconnecting parameters.

[dorn]

Nov 23, 2019 7:54:33 GMT -6 akosjaccik said:

While I'd not like to address the exact numbers either way, I'd still like to point out a factor in the game that perhaps does not get enough attention and things sometimes suffer because of it - and that would be game size. For example, to my knowledge (which might be dated by this point, but there is a fair chance for it being correct) hard-coded airfield sizes, among other things, do not scale with game or fleet size, resulting in "Small", "Medium" or "Very Large" campaign players equally having to deal with 120 a/c airfields built up in every village by the AI.
Maintenance time can be one of these unequalizing factors, as IF the events regarding that do not scale (for example, if for one reason or another there is no significant difference in the players' capital ships getting torpedoed by subs), then the "Small" player might have to make do without 10-40% of his main forces, whereas a "Very Large" (or above that, as on Discord modding fleet size is relatively common) player might not care about a couple extra months at all.
Once again, without hinting at actual numbers or anything - I just wanted to point out that there are other, interconnecting parameters.

It is linked to this topic.

There has been made some changes however I do not know as I play quite slowly if it was enough. If AI is able to adjust with the smallest fleet available.

However they would be always difference between the largest and smallest fleet available. I consider it good as it adds another variety in this game. Main point is it needs to be still challanging in similar manner and AI can be able to handle it.

[sloanjh]

Nov 22, 2019 7:08:59 GMT -6 wlbjork said:

Difficult to know as this is quite clearly "hidden under the hood".

Presumably, Mainz suffered from a "silver BB" (maybe only bronze) - that is, the shell came in and took out critical propulsion components that are easily replaced in a dockyard setting, but not a major component(such as a boiler).

Thetis on the other hand - despite requiring a complete superstructure rebuild - is also going to be repaired suspiciously quickly.

Further investigation would seem necessary - perhaps a check of each hit in the log in future battles?

Coming back to the OP's question, I think that this explanation is likely to be true.  I don't have a detailed analysis, but I think I've noticed that things like torpedo hits tend to have much longer repair times than other forms of damage.  So I suspect that under the hood the game is keeping track of exactly what got damaged and is applying an associated repair time to each item of damage.