Im going to try to answer how long system damage should take to come off.
Basically two weeks in Pearl or other major port should do it, for the 1st 2 years of ops, (if the port visits happen every 4 months at the max). The next port visit then, allow 3 months for Refit, at least.
Heres why-. Basically all maintenance in those 1st 2 years of ops revolves around the boilers, 95% of other jobs(pump rebuilds, turbine inspections, condensor cleans, valve replacements), can all be done relatively quickly,but the boilers, especially in those days were a buggar.
In my day, we burnt dieso, and this is very important, dieso doesnt choke boiler tubes , FFO does, big time.
I always cleaned my boilers chemically, 1st, cool boiler, 12 hrs.chuck in chemicals, staem boiler for 4 hrs.
cool for twelve hrs
Fill and dump several times(8 hrs)
Open up boiler(8hrs)
Inspect
Close up boiler
Fill and pressure test, this might not work and need several goes, 8 hrs
Box up, light of and establish chemistry.
If all went to plan we could start on Friday, finish monday
Now for WW2 methods, which I have done just once .
Open boiler
Remove all internals-2days
High speed brush clean each tube-1600 odd tubes-3 days:eek:
sight each tube with balls, 1 day
put back together, 2 days
Pressure test, re light off
However all the externals had to be cleaned off the soot, Ive never done that, but have seen old movies, this horrible job took at least 3 days, washing the tubes, or dry brushing them.
So, we have about a week a boiler, times 4 boilers, you can do two at once, but never all four at once, as you need the power!
A BB or CV is different, they have 8 boilers, and did them at sea, simply shutting down one boiler room for a week, in a continous rotation. For them, a constant system damage of 8 would be realistic, with damage of 1 at 48 hrs notice(Get to work!)
But poor old DDs are very fragile, we need port time!
Any way, hope I dont sound confusing.
Truth is, some skippers are just like some UV players, they want 0 system damage all the time, they aint going to get it.
I do think UV gets accumalation right, but repair could be a bit quicker(not much experience on that yet, I drive the Imperial fleet into the ground, half my ships have system damage 20 or more, and they wont be going home until Cairns is in my hands!)
PS Beer is good