Simming destroyers - alternative

[P3D]

Dreadnoughtprojects.org has two destroyer plan.
I was surprised what the 'light construction' means for destroyers.
The hull is one single box. So much that sometimes there aren't any longitudinal bulkheads, and neither any additional decks running all the length of the ship. If there are longitudinal bulkheads, they are usually oil bunkers or reserve feed water tanks on the hull sides.
The machinery rooms fill out essentially the whole hull cross section.

[The Rock Doctor]

Hmm...

The program's limitations for small craft has been a topic of discussion since I've been aware of it.  I've seen people at Wesworld discuss the light weight of light guns and how it allows for unreasonable armaments.  There are a couple of ways to go about this:

1)  The complicated way is to add miscellaneous weight for each weapon shipped.

2)  The simple way is to accept that it is a program flaw, but one that can be tolerated since it affects everybody equally.

Having too much stuff on a certain amount of deck space is a problem too.  I'm not sure there's an easy answer for this - be able to point to a historical analogue?  Some sort of rule of thumb?

On machinery - use of a transom stern on a design boosts hull strength and speed for any given design.  Although it's ahistorical, if we introduce the use of a transom stern as a consistent "cheat" for ships bound by the "destroyer architecture" tech, maybe we get more accurate designs (other than the shape of the stern).

Question:  when wargaming, how do the mods determine the affects of sea state on destroyer speed, and how important is the SS value for that destroyer?  If we understand this, and it turns out we're using high freeboard to get the decent seakeeping values we don't actually need, we'll naturally drop the freeboard some in order to use extra hull strength elsewhere.  No rules required.

[Tanthalas]

I will now admit I stole my destroyer's lol, battle ships, and my funky 6 gun heavy cruisers.  They are all based on historical ships.  What I do is I take a ship that actually existed, and then adjust it to my tech.  My goal is to make them as fast, and as cheap as I can.  Which is also why I have 28 and 30 kts destroyers, and also why I am still playing around with a 4500 ton cruiser with 8" guns and 28 kts top speed?  I have had triple TT tech since I started.  And I don't feel that 2 triple launchers are out of place on a 750-1k ton ship.  I try for as much realism in my designs as I can get.  As is im working my ships up in SS3 and then converting them to SS2, to post them.

[Borys]

Ahoj!
To the torpedo itself I add the wieght of the tube, the mount, the strenghtehing of deck in that place, etc.

Borys

[P3D]

On machinery - use of a transom stern on a design boosts hull strength and speed for any given design.  Although it's ahistorical, if we introduce the use of a transom stern as a consistent "cheat" for ships bound by the "destroyer architecture" tech, maybe we get more accurate designs (other than the shape of the stern).

Question:  when wargaming, how do the mods determine the affects of sea state on destroyer speed, and how important is the SS value for that destroyer?  If we understand this, and it turns out we're using high freeboard to get the decent seakeeping values we don't actually need, we'll naturally drop the freeboard some in order to use extra hull strength elsewhere.  No rules required.

I'll try out and see if transom stern helps. It should.

Sea state: Seekrieg 4 has weather tables depending on location to determine sea state. There are tables that tells how the sea state affects ships of a given size. Then use some handwaving about the actual seakeeping stat - which also has effect on gunnery.
I will put all the stuff I use for resolving battles on the forum - that would also help me a lot.

[Borys]

Ahoj!
The Battlecruisers and Warship Projects both are good sites. There is overlap in members between them and Warships1, but I sometimes find the threads at those two more informative than at Warships1.
Now that you mentioned seatates - there was something not so long ago about the RN changing its early XXth century policy. That destroyers were rated on 4h sustained speed, not trial mile mile speed. And that a class rated at 27 knots was actually faster than a class which had 30 knots in the specification.

Borys

[P3D]

Yes destroyers were rated at 3-4-6hr sustained speed. And not at a light displacement.

[Borys]

Ahoj!
But this was intrduced somewhere in the 1905-1910, IIRC.
Damn, can't find that thread - not being sure which board it was at, and having no idea what the thread was titled DOES make searching difficult :)

Borys

[P3D]

Full power trials even for the A class (1893) lasted for three hours. The speed was determined by making the measured mile repeatedly (4-6 times), with and against the tide.
Comet (1910) had 8-hour trial.

Source is March: British Destroyers.
Made a visit to the library. ;)

[Borys]

GASP!
:)

[P3D]

Transom Stern in SS2 would give about 1.5 knots.

[maddox]

I can agree on the .75 composite strength and transon stern on 750 tons DD's or better.  Even .5 cross sectional is acceptable.

This doesn't change the base of the Nverse, Springsharp2.

Further option, to offset the "heavy engines" is to allow higher HP and later engines for DD's.  Again something that is easy, and in perfectly doable in SpringSharp. 
Like 1000 tons DD tech, layed down 19XX engine date 19XX +7 years

[Borys]

I can agree on the .75 composite strength and transon stern on 750 tons DD's or better.  Even .5 cross sectional is acceptable.

Like 1000 tons DD tech, layed down 19XX engine date 19XX +7 years

Looks OK to me ...
Plus 20" torpedos should be accounted for at the rate of 2 tonnes each (before reloads).
Or should I sig that?
:)
Borys

[Walter]

The hull is one single box. So much that sometimes there aren't any longitudinal bulkheads, and neither any additional decks running all the length of the ship. If there are longitudinal bulkheads, they are usually oil bunkers or reserve feed water tanks on the hull sides.
The machinery rooms fill out essentially the whole hull cross section.

When I read that bit regarding the machinery room you typed, P3D, then it states that part of the machinery is also in the above water section of the hull. If I am not mistaken, Spring Style/Sharp assumes that all machinery is below the waterline. The fact that part of the machinery is above the water should have a serious impact on the stability of a ship of destroyer size and for that reason, I doubt it is correct to do what Ithekro did and compare destroyers with a unusually high freeboard to a modern cruise liner with a very high freeboard (at least it looks to me that he is comparing the two with eachother and stating that if the cruise liners can have such a high freeboard, the DDs can have them as well; correct me if I am wrong here Ithekro).

I've seen people at Wesworld discuss the light weight of light guns and how it allows for unreasonable armaments.

I think it is more a size problem than a weight problem. I think there is no problem that the vessels can handle the armament weight. The actual problem is that there would be very little space (or maybe even no space at all) left to properly operate the gun and SS doesn't take that properly into account.
Another reason for some of the designs is (at least in my eyes) because of our rules that state that vessels <3,000 tons and with a speed >24 knots allows one to sim a 2,999 ton ship with a speed of 24.05 knots which would be allowed to have the minimum x-sectional strength of 0.50. With a ship of that size and low speed, one has plenty of hull strength left to put lots of guns on the vessel as well as lots of armor. The sole purpose of my Senshi class (http://88.198.26.117/kunden/oponn/wbblite/thread.php?postid=30438#post30438) was to completely destroy that particular rule we put into Wesworld and try to figure out something else  that would work better and counter the ability to abuse this rule (like what I had in mind with the square root of the length wl and multiply that with 1.5; the resulting number would be the minimum speed required to take the hull strength below 1). My plan failed miserably and we still use that rule (I think I might want to give it another try).


Regarding hull strength and transoms...
I made a number of tests yesterday with Japanese destroyers in the 750-1500 ton range. All the hull strengths I got were in the 0.5-0.55 range with exception of the Urakaze (0.73) so I do not agree that we should raise the minimum composite strength to 0.75.
I don't believe in using the transom stern option as it is out of place on vessels of this era. All of those DDs I did yesterday were simmed without the use of the transom stern option and using the hull strength rules as they are now. I had no problems with them so there is absolutely no need to use the transom stern option.

I seem to recall that a while back someone (don't remember who) made the remark on one of the message boards (don't remember which one) that the maximum speeds given in those sources was the speed obtained during trials and was higher than the maximum speeds obtained during service and that the speeds given in the various sources are not the ones you need to enter into SS. Now I could be completely wrong about recalling something like that, but it was for that reason that I simmed the Navalism DDs and TBs based on engine output and not on the given speed. I assume that the given speed on that site I use is the absolute maximum that the ship can acchieve in speed trials.

[Carthaginian]

P3D,

If the program is broken, then it's broken for everyone.
Thus, we'll all have the same benifits and drawbacks.
To me, this isn't broken in a bad way, because it's broken equally.

My destroyers are higher in freeboard than some historical destroyers, but not by massive amounts. I'll admit that they are based on 1920's designs more heavily, but info on the web for the oldest destroyers is limited, and I can't afford all the books that you and some of the more hardcore guys have. I do the best I can with what I have, and try to keep my designs within realistic limits.

We don't have to keep changing the rules every time we check back in just because there is a better way of doing things.


My take on it:
Good enough generally is, while perfect is always a pain in the ass and generally not worth the extra effort.

If what we have right now is allowing everyone to build destroyers that are equal ALL THINGS CONSIDERED, then it's OK for our little world.