Considering I'm not enthused with the idea of maintenance in the first place, I really don't know why I spent the time to come up with this- must be my "talent" for long, overly complex and wordy documents coming to the fore.
I've went and muddled this up, but here's a short summation, followed by a long, and overly elaborate explanation as to why. Sometimes I dare people to ask me to explain things, consider yourself warned....
Presuming that everyone has a spreadsheet they use to track ships, whether Open Office, Lotus, or Excel.
You'd need Normal (tonnage), Category, Status and "Maintenance" columns
First - I think there should be several 'categories' of ships, with different maintenance rates. Rates are examples.
A) 5.0 Example vessels :
Submarines- I've read several times that Subs cost as much as a cruiser to run, because of the engineering, machinery and training. 6 x 1500= 9000, so that seems about right.
B) 1.0 Example vessels :
Destroyers- Lightly build, delicate machinery,
Carriers in the case of carriers, not only do you need a responsive powerplant, but there are planes to maintain.
C) 0.75 Example vessels :
Cruisers- Economical, solidly built, well armed;
Escorts heavily armed escorts.
Seaplane tenders. again due to aircraft support.
D) 0.6 Example vessels :
Battleships- Robust, powerful machinery and hulls Escorts : lightly armed & overbuilt escorts
E) 0.20 Example vessels : Support vessels, minelayers, tenders, subchasers- pretty much minimum crews and power plants.
Second that there should be several "Status" levels
A) 1.2 Combat : Manned, extensive sea time, expends ammo. Note this is 1.5 * operational, though I am still not sold on this number.
B) 1.0 Active : Manned, extensive sea time and training munitions expenditure.
C) 0.8 Operational : Manned, limited sea time and training round expenditure.
D) 0.20 Reserve. Tied up at dock, skeleton crew ensures maintained, engines run, manned by naval reserves.
E) 0.1 Laid up. Mothballed, annual inspections, no crew. Needs minor refit to activate.
Maintenance would be
Light * Category*status*0.054 = tons/year.
So, the USS South Dakota at war would run : 36,367 * 0.6 * 1.2 * 0.054 = 1,414 tons
The French Algerie would absorb : 9,485 * 0.75 * 1.2 * 0.054 = 461 tons
a Destroyer Squadron of Anderson Class DDs would run : (1425* 8 ) * 1 * 1.2 * 0.054 = 752 tons
and a squadron of Polish Orzel class submarines would take about (1487* 8 ) *5.0 * 1.2 * 0.054 = 3,854 tons (482 each, a touch more than Algerie)
How to pay for it?
Call it maintenance points, MPs
Factory output as maintenance is one method, and allows stockpiling = 1,000 MPs / Q or 1,250 MPs / Q if dedicated.
Under the category and under the
ounce of prevention is worth a pound of cure
Drydocks should produce some maintenance as a representation of repair facilities = 110 MPs / IP invested.
Dedicated tenders should produce some as well, as another form of repair facility = 28 MPs / 1,000 tons light displacement
Conversion to Normal tonnage- Normal seems to run 10-20% more than light. Using 15% more the guide, then :
Normal * Category * status * 0.047 should yield similar results.
Now, since I've proposed this, I went through the exercise of doing my fleet.
The difference between escort and heavy escort seems valid- the heavily armed S19 class costs 25% more to run than the FF1 class. I ran into issues with my habit of recording things like MAS 1000 as 12x MAS 1934. etc. So it's not entirely accurate, but close. Most combat vessels are active (to reflect a high state of training), most support in reserve, with patrol being operational or active.
Total required : 31,684 maintenance points.
Tenders : 1,114 mps
Drydocks : 37 IPs = 4,070 mps
Annual deficit : 26,500 MPs.
(We can always add Factories and Slips if we so choose. )
This deficit can be made up by 5.3 factories being dedicated to maintenance, or slightly over 1/3 the Dutch manufacturing base.
Since most of my combat tonnage was Active, going to wartime appears achievable without collapse, though 7-10 factories might need to be committed.
It's a little more complex than desirable, but feels decent. I don't like the result, but I don't think I was supposed to given I am not agitating for maintenance in the first place.
WHY???
Well I was working from a couple of data point and a ton of wishful thinking work.
This 1950 article is interesting
http://www.time.com/time/magazine/articl…13416-3,00.html
The bit about a 1940 destroyer costing $293,000 / year is especially interesting.
By 1940 the USN was prepping for war, and engaged in North Atlantic "Nuetrality" patrols, so this likely represents a fairly active vessel, not one laid up.
But for what destroyer class? or is that an average? We don't know.
If we use a 1,500 ton destroyer, the cost works out to $195.33/ std. ton.
Using an 1935 (completed 1939-40) Anderson Class, 1,570 standard ton DD as a base, we can put it in SS2.
SS2 does not like it, gives it a 0.09 hull str), and it comes to 1425 tons
light, while it costs about $4.723mil in 1935, or 5.477mil in 1940 to construct. Interestingly, Jane's states they cost $7,000,000 each, but American construction was comparatively expensive.
IF 1487 tons (light) = $5.477 million for construction.
Then 1 ton (light) = $3,663 for construction.
Given that Operations is $293,000 / year, this gives worth (293,000/3663) of 80 light tons worth of material.
This is 5.38% of the ship's material value, for an expensive to operate vessel likely engaged in active open sea service.
So this made the baseline value to work off of 5.4%.
There seemed to be two main variables- type of vessel and type of use. So I made up categories and assigned values for those.
For type, there seemed some logical groupings
Destroyers would be the baseline 1.0 value. Cruisers should be cheaper. Subs reportedly cost as much to run as cruisers, but the latter are usually 6-8 times larger than subs. 3/4 * 6= 4, 3/4 * 8 = 6, and 5 is in the middle. Fancy, no?
Active was my presumed operational level. Since ammo is not being expended, I put combat above that. Presuming that this represents more than simple peacetime service is less I placed operational below. Since others wanted combat to be 1.5 * operational, I made that work. Since the 1946 USN budget was about 1/6 of the 1944, I put reserve as 1/6 of combat. Also that 1950 article puts the maintenance part of the budget at 26%, but not all the USN was laid up, so 20% seemed ballpark. Terribly scientific.
The factories as maintenance
As for the drydocks and tenders-
A previously floated idea included drydocks at 2,000 tons * IP /year, so 2,000 * 0.054 = 110 * IP = # MPs
I don't include slips, but it could be done.
Tenders should also be useful, and don't do anything but support the fleet, while drydocks are useful for other things. So I think Tenders should be twice as valuable.
So it takes a minimum of 8,000 "lost" factory output to yield 1 IP, taking 2 years at 4,000 a year. So 110/8 = about 13.75 per 1,000 tons , but double that = about 28 MPs for every 1,000 tons of tender.
We can always add Factories and Slips if we so choose.