Are we overdesigning destroyers?

[Guinness]

Thank you very much Guinness for the info.  If we are talking about TB/DD's I have the following other comments.

Glad you liked it. I'm working on more of the same now.

If we are going to restrict guns and torp mounts then lets do it. Tie the number of weapons / mounts to the tech level or something.  I looked at a number of USN DD's of WW2 and some, many, of ours have more firepower.

I'm not sure that rules limiting gun numbers or something like that are the way to go, but that might certainly be an option. Some guidelines about how much deck area per mount type is needed might help. Also, I'm thinking about a better way to calculate crew requirements based on armament, instead of just using displacement like SS uses.

Can we change it that if you add or remove things noted in misc weight like depth charges or mine sweeping gear, etc it can be done with just time along side the pier and no other cost?

That's my assumption. Gear that can be reasonably bolted on by ship's crew and kept in inventory for later shouldn't require extra costs, as long as the ship was designed for that capability from the get go. Most of this sort of equipment is easily swappable, but some work on ship's structure to support things like winches or mine tracks would have been required.

[Guinness]

Got back to this project tonight. Here's two updated tables for RN and USN DDs (and a couple of DEs) up through the end of WW2.

RN:

Ship Year Displ.* SS BC Guns TTs Trial Speed Fuel SS Speed SS Avg Fbrd SS Seakping Notes HMS Albatross 1900 430 0.421 1x3in, 5x2.24in 2x18" 31.4 Coal 27.4 8.3 0.79 Trial at "light displacement" HMS Kennet 1903 540 0.441 1x3in, 5x2.24in 2x18" 25.89 Coal 25.89 8.14 0.7 Trial run at 600t displacement HMS Velox 1904 400 0.44 1x3in, 5x2.24in 2x18" 27 Coal 27 7.94 0.59 Trial speed is rated "normal" speed HMS Swift 1909 2170 0.533 3x4in 2x21" 35.037 Oil 32.9 13.05 0.69 Trial run at "normal displacement" HMS Acasta 1912 892 0.46 3x4in 2x21" 29 Oil 30.2 9.14 0.5 Trial run at full load, 8 hours running time HMS Maori 1914 972 0.503 3x4in 4x21" 34 Oil 34 8.92 0.21 Trial at "normal displacment" HMS Matchless 1914 971 0.507 3x4in, 2x2pounder 2x21" 34 Oil 35.01 9.63 0.25 Trial run at "normal displacement". Very low steadiness in SS HMS S-Class 1918 1000 0.537 3x4in, 1x2pounder 4x18" 36 Oil 33.35 10.24 0.39 Trial run at "normal displacement" HMS W-Class 1918 1379 0.55 4x4.7in, 2x2pounders 6x21" 34.8 Oil 33.3 12.3 0.62 Trial run at "normal displacement" HMS A-Class 1930 1330 0.539 4x4.7in, 2x2pounders 8x21" 35.9 Oil 34.5 11.72 0.42 SS 1.10 stab, 45 steadiness, 0.50 CrossSectional, 46 tons misc weight, Engine Year: 1930 HMS H-Class 1936 1350 0.539 4x4.7in, 2xquad 0.50 8x21" 35.5 Oil 34.8 11.68 0.36 SS 1.11 stab, 43 steadiness, 0.50 CrossSectional, 46 tons misc weight, Engine Year: 1936 HMS Tribal 1938 1882 0.52 8x4.7in, 1xquad 2 pounder, 2xquad 0.50 4x21" 36.5 Oil 32.2 15.47 0.91 SS 1.10 stab, 78 steadiness, 0.50 CrossSectional, 60 tons misc weight, Engine Year: 1938 HMS L-Class 1940 1948 0.516 6x4.7in DP, 1xquad 2 pounder, 2xquad 0.50 8x21" 36 Oil 33.3 12.69 0.61 SS 1.10 stab, 52 steadiness, 0.50 CrossSectional, 70 tons misc Weight, Engine Year: 1938 HMS Hunt (III) Class 1940 1050 0.52 4x4in, 1xquad 2 pounder 2x21" 27 Oil 27 9.8 0.52 SS 1.10 stab, 45 steadiness, 1.00 CrossSectional, 145 tons misc weight, Engine Year: 1938 HMS N-Class 1941 1707 0.45 6x4.7in, 1xquad 2pounder, 2xquad 0.50 10x21" 36 Oil 34.6 13.29 0.61 SS 1.10 stab, 55 steadiness, 0.50 CrossSectional, 50 tons misc weight, Engine Year: 1938 HMS War Emergency 1942 1734 0.45 4x4.7in, 1xquad 2 pounder, 6x20mm 8x21" 36.5 Oil 34.4 14.92 0.83 SS 1.10 stab, 79 steadiness, 0.50 CrossSectional, 50 tons misc weight, Engine Year: 1938 HMS Battle Class 1945 2322 0.52 4x4.5in, 1x4in,8x40mm, 6x20mm 8x21" 35.75 Oil 35.85 13.51 0.53 SS 1.10 stab, 50 steadiness, 0.50 CrossSectional, 70 tons misc weight, Engine Year 1940 * Normal for Ships up to the A-Class (1930), Standard after that

USN:

Ship Year Displ. SS BC Guns TTs Trial Speed Fuel SS Speed SS Avg Fbrd SS Seakping Notes USS Bainbridge 1899 420 0.43 1x12pounder, 5x6pounder 2x18" 28.45 Coal 26.05 9.76 0.98 1.19 stability, 98 steadiness, 1905 engines (reciprocating) USS Smith 1909 700 0.407 5x12pounder 3x18" 28.35 Oil 27.95 9.5 1.02 1.27 stability, 100 steadiness USS Wickes 1918 1160 0.47 4x4" 12x21" 35.34 Oil 32.29 10.87 0.54 1.10 stability, 47 steadiness, 1920 engines USS Farragut 1932 1500* 0.522 5x5", 4x0.50" 8x21" 36.6 Oil 34.47 11.19 0.28 1.10 stability, 36 steadiness, 1932 engines, 50t misc weight USS Bagley 1935 1500* 0.457 4x5", 4x0.50" 16x21" 36.8 Oil 35.8 10.31 0.15 1.10 stability, 22 steadiness, 1936 engines, 60t misc weight, seakeeping at 32 knots:0.28 USS Somers 1935 1850* 0.482 8x5", 8x1.1", 4x0.50" 12x21" 38.56 Oil 33.65 12.35 0.5 1.10 stability, 45 steadiness, 1936 engines, 70t misc weight USS Fletcher 1941 2259 0.499 5x5", 4x1.1", 6x20mm 10x21" 35.1 Oil 35.1 10.25 0.29 1.10 stability, 38 steadiness, 1941 engines, 80t misc weight USS Buckley 1943 1540 0.52 3x3", 2x40mm, 8x20mm 3x21" 27.3 Oil 27.3 11.14 0.63 1.10 stability, 51 steadiness, 1941 engines, 180t misc weight USS Gearing 1944 2868 0.54 6x5", 16x40mm, 20x20mm 5x21" 33.82 Oil 33.82 11.76 0.4 1.10 stability, 45 steadiness, 1941 engines, 130t misc weight * Standard displacement (rest are normal displacement)

Based on these numbers, I think we can conclude we've all been building DDs with too much freeboard, at least compared to OTL. With more historically realistic freeboard heights, much closer to OTL speeds are possible with SS, especially on boats above 700t light or so.

What's a good range for the SS freeboard value? If we accept that RN boats were generally better seaboats than USN boats, I think we can use the RN numbers as upper bounds, and the USN numbers as lower bounds. Doing a sort of by eye estimation based on the data above (ie, not using any real statistical techniques, but just going by how it feels), I think that the lowest bounds for a DD is probably around 0.20, average is about 0.5, and anything over 0.6 is quite good.

[maddox]

For now, Glorious France won't build DD's with a lower seakeeping than 1.0

It's just a French thing we could say.

[Desertfox]

How about the Swiss? Where my DDs are closer to mini-cruisers, than overgrown TBs? I have deliberately sacrificed speed for range and seakeeping. Others might not need those qualities, but then I'm sending my ships on cross-Pacific missions.

[Tanthalas]

I would say use the average (around .50) as a botom number and leave it up to individual players to determine the speed/seakeaping of their cans.  This isnt OTL, and I would rather it be left up to the players how things work in their navies...

Besides any change at this point in the sim would affect a Very large number of ships, which would to be rather frank be a pain.

[Guinness]

How about the Swiss? Where my DDs are closer to mini-cruisers, than overgrown TBs? I have deliberately sacrificed speed for range and seakeeping. Others might not need those qualities, but then I'm sending my ships on cross-Pacific missions.

The USN designed its DDs, especially those of the 30s and later, expressly for long-range Pacific service, so I'm not sure the Swiss aren't overemphasizing those qualities. Except at the very furthest north and south latitudes, or during the occasional typhoon, Pacific weather is generally much better than that expected in the winter in the N. Atlantic. The Fletchers in particular were considered above average seaboats during operations in the Aleutians, in winter, for instance.

At any rate, this exercise isn't meant to lead to widespread rule changes, but rather to raise awareness as to just how much our general assumptions about DD design diverge from historical, and to illustrate that boats with less freeboard and more speed are perfectly reasonable, and further, that it is distinctly true that Nverse boats are generally overarmed. I hope this will inform designs in the future.

Now, having said that, this doesn't mean there might not be some sort of rule change contemplated in the future. For instance, this data seems to illustrate that it might be reasonable to adopt some sliding scale for minimum BC based on displacement (or something). Also, both the USN DE (Buckley) and the RN Hunt Type III were easily simmable to 1.0 overall strength which may inform some future nudge up of the minimum speed for a ship built to the 0.50 cross-sectional strength rule.

Also, I think Friedman's books have provided useful data for misc weights for various equipment:

10t: Mine/Submarine sweep, possibly with a 20t version for dedicated minesweepers
10t: Sonar/Asdic
10t (or maybe as much as 20t): Permanent equipment to allow laying of mines, possibly coupled with a reduction in weight per mine such that 2t = 3 mines (maybe). There seemed to be a few mines that totaled 1t in weight being layed, but I believe there the majority of sea mines layed were actually smaller, so we might want to find a more "customizable" system, which also captures the fact that giving a ship real minelaying capability cost something too.

Basic fire control weights at some point might simply be part of the weight of the ship, similar to short-range wireless now. This would get you basic surface fire control. AA or DP, Radar guidance, etc. etc. might require some extra amount of weight still. Certainly, by WW2, 25t on a DD would not nearly cover the extra weight required of a combination SP/AA or a true DP FC system, so eventually something will need to be done.

Maddox: I believe that French boats due to their characteristic ram bow generally have worse seakeeping than SS gives them credit for.

[Guinness]

Oh and to expand on the question of freeboard: if you look at the average freeboards of these boats, you'll notice a steady and gradual increase as their size increased. I believe this happened for two reasons, neither of which had anything to do with their "seakeeping" as we know it via SS's seakeeping value.

First, as destroyers got longer, their hull depth by necessity had to increase to maintain sufficient strength in the hull girder.

Second, as their bunkerage increased, the hull had to be deeper to ensure sufficient minimal freeboard when fully loaded. This sufficent freeboard was more or less what previous boats had been designed to have (ie more or less one deck aft, and two decks forward on a ship with a raised forecastle).

Considerations that we'd consider to be primarily seakeeping seemed only tertiary. For instance, the RN added sheer forward (and Atlantic bows) to their late 30's and later designs in an attempt to reduce the amount of green water that would be shipped over the bows in rough weather. Stlll, these additions hardly made for "good" seaboats according to SS. Also, it's obvious that OTL designers accepted a certain amount of water and spray: this was the reason that only the forward main armament had shields in so many interwar American designs.

[maddox]

I know SS isn't good in simming  small ships. But that's the same for everybody, isn't it?


Guinness, most French ships have weathershields over the guns, even the 37mm AA, all for crew comfort. Even with the ram bow crews will have some comfort when manning the guns. Some even have coffee thermos bottles in designated mounting supports inside their turrets. It's part of the crew comfort program.

In any case, we have on 1 side the complaint our DD's are overgunned and slow, on the other hand too good in seakeeping and low on torp armament.

If people want ships with superiour seakeeping, sacrifices will have to be made, it's all in the Triad of Power. Propulsion, Protection, Firepower.

I myself prefer a ship with good seakeeping. And have sacrificed protection to achieve a rather useable turn of speed on the small ships, and the other way around on the big boys.

[Kaiser Kirk]

Whoa, nice work there

I think that the lowest bounds for a DD is probably around 0.20, average is about 0.5, and anything over 0.6 is quite good.

From this and the subsequent chit chat about French or Swiss DDs, how to apply to existing ships, etc. I am thinking the solution is to declare that ships built to DD architecture get a +0.4 bonus to their seakeeping value for "sim" concerns regarding weather etc.  Thus all old ships are 'upgraded' to better seaboats, and future builds can push that down as desired. A DD built with 0.3 becomes 0.7, while 1.0 becomes 1.4

USN DE (Buckley) and the RN Hunt Type III were easily simmable to 1.0 overall strength

Yes, but those were escorts,  Escorts are a different kettle of fish, as they were designed for different goals. They would have less fragile machinery, lower crews and a design goal of being 3+kts faster than a surfaced sub.  Dropping 7knts from our DDs will often result in much better seakeeping and hull strength. In Navalism terms, they should not be built to destroyer rules most likely, as folks would not want to pay the +25% cost of doing so.

Maddox: I believe that French boats due to their characteristic ram bow generally have worse seakeeping than SS gives them credit for.

Hey, style points add flotation !
....which could be why Bavarian vessels todate have ram bows...though in the smallest TBs they are turtlebacks for wave piercing.

[miketr]

Would it be possible for us to resim our ships as long as we keep light displacement the same?  I am going to see what I can do if I accept far less seakeeping.

[Guinness]

The Mods will discuss the idea of retconning ships built to the TB/DD rules, and continuity in that respect in general, but my personal initial impression is that some may want to do that, some may not want to do that, so it's probably not feasible.

To deal with this, I'm thinking it might be a good idea for one of us Mods, or a volunteer, to write a story about their naval architects doing an extensive study on the characteristics of their DDs for a future design, and coming to the realization that they needn't have nearly as much freeboard as has been the norm. What might result would be as revolutionary as Dreadnought or Turbinia were OTL. The rest of us could react to it.

The TB I'm working on for the Ottomans might be such a ship, but I fear a more influential nation really ought to be the one to take the leap first to make it sensible that others who see it the same way would follow suit.

[Borys]

Ahoj!
I'm in the "won't be bothered to redesign" camp. As the life of such ships in my fleet is 10-15 years, they'll be replaced by new designs soon enough ...
Borys

[hooper82]

Does SS3 change things?  I assume that Guinness tables where based on SS2?

[Tanthalas]

Does SS3 change things?  I assume that Guinness tables where based on SS2?

SS3 makes some changes to it, you get better preformance on light fast hulls over all.  The real gem in it (if its ever enabled anyway) is the engine slider.

[The Rock Doctor]

If I reduce freeboard and draught, and increase BC, while keeping length, beam, and light displacement constant...

My V class boats drop to 0.65 seakeeping, lose a bit of misceallenous weight, and gain a knot of speed (33.1 kts)