A significant change from the previous class(es) in... well, most respects. The guns are imported, Confederate 4.75"s relined for a metric nation. Drawing as soon as I get around to uploading it now.
(http://i31.photobucket.com/albums/c386/valles_uf/DE-1913.png)
Dawn Under Heaven, Maori Destroyer laid down 1912
Displacement:
1,000 t light; 1,038 t standard; 1,230 t normal; 1,384 t full load
Dimensions: Length overall / water x beam x draught
300.28 ft / 295.28 ft x 29.53 ft x 9.84 ft (normal load)
91.52 m / 90.00 m x 9.00 m x 3.00 m
Armament:
3 - 4.72" / 120 mm guns in single mounts, 52.72lbs / 23.92kg shells, 1912 Model
Quick firing guns in deck mounts with hoists
on centreline, evenly spread
Aft Main mounts separated by engine room
Weight of broadside 158 lbs / 72 kg
Shells per gun, main battery: 150
6 - 17.7" / 450 mm above water torpedoes
Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.98" / 25 mm 0.12" / 3 mm 0.12" / 3 mm
Machinery:
Oil fired boilers, steam turbines,
Electric motors, 2 shafts, 18,345 shp / 13,685 Kw = 28.00 kts
Range 4,000nm at 14.00 kts
Bunker at max displacement = 346 tons
Complement:
103 - 135
Cost:
£0.133 million / $0.531 million
Distribution of weights at normal displacement:
Armament: 20 tons, 1.6 %
Armour: 4 tons, 0.4 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 4 tons, 0.4 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 580 tons, 47.1 %
Hull, fittings & equipment: 347 tons, 28.2 %
Fuel, ammunition & stores: 230 tons, 18.7 %
Miscellaneous weights: 50 tons, 4.1 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
401 lbs / 182 Kg = 7.6 x 4.7 " / 120 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.26
Metacentric height 1.2 ft / 0.4 m
Roll period: 11.2 seconds
Steadiness - As gun platform (Average = 50 %): 79 %
- Recoil effect (Restricted arc if above 1.00): 0.48
Seaboat quality (Average = 1.00): 1.29
Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.502
Length to Beam Ratio: 10.00 : 1
'Natural speed' for length: 17.18 kts
Power going to wave formation at top speed: 66 %
Trim (Max stability = 0, Max steadiness = 100): 61
Bow angle (Positive = bow angles forward): 5.00 degrees
Stern overhang: 3.28 ft / 1.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 19.69 ft / 6.00 m
- Forecastle (20 %): 14.76 ft / 4.50 m
- Mid (50 %): 13.12 ft / 4.00 m
- Quarterdeck (15 %): 13.12 ft / 4.00 m
- Stern: 13.12 ft / 4.00 m
- Average freeboard: 14.09 ft / 4.30 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 168.9 %
- Above water (accommodation/working, high = better): 96.3 %
Waterplane Area: 5,819 Square feet or 541 Square metres
Displacement factor (Displacement / loading): 73 %
Structure weight / hull surface area: 29 lbs/sq ft or 140 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 2.32
- Overall: 0.58
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is adequate
Ship has slow, easy roll, a good, steady gun platform
Good seaboat, rides out heavy weather easily
6 tons torpedoes
10 tons short-range wireless
9 tons miscellaneous weight
25 tons destroyer fire control
Quote from: Valles on May 04, 2008, 02:19:39 PM
Dawn Under Heaven, Maori Destroyer laid down 1912
I think her BC is very much on the high side for such as small ship, lowering that could save quite a bit of weight.
Cannot shake the feeling that the ship could be a bit more optimised, comparing it with my own 1912 design she got two guns less, almost two knots less and shorter range, and this is return for just ten tons of misc weigh and two torpedoes.
Always good to see a drawing of how things fit together :)
Destroyers aren't meant to do most of their killing with their guns anyway, otherwise the Maori would've stuck with their native 150s for all the problems of mounting them...
*shrug* Springsharp is determined to punish me for wanting a flush deck? Every 'slightly improved' version I came up with ended up ten to twenty tons over the weight limit. Also, note the cruising speed - at 12 knots she's good for... *checks* ...5,800nm. As it is, she's a good shooting platform and a decent seaboat and a knot faster than the last class.
And next tech level I'll take another crack at giving them armor, and won't that be fun? ^_^
Quote from: Valles on May 05, 2008, 03:55:38 PM
Destroyers aren't meant to do most of their killing with their guns anyway, otherwise the Maori would've stuck with their native 150s for all the problems of mounting them...
Difference in doctrine then. As I (and the Netherlands) see it, guns are the primary weapon of a destroyer, and it primary purpose is to destroy the enemy equals, and cripple enemy cruisers.
Quote*shrug* Springsharp is determined to punish me for wanting a flush deck? Every 'slightly improved' version I came up with ended up ten to twenty tons over the weight limit.
Springsharp does not punish you for going flush deck. It punish you for going for a very fat hull for a destroyer, increas her length 9m and I suspect you would get a more capable ship.
QuoteAlso, note the cruising speed - at 12 knots she's good for... *checks* ...5,800nm. As it is, she's a good shooting platform and a decent seaboat and a knot faster than the last class.
Did note the cruising speed, but as I knew the boat I compared her to (H-class) had a range of almost 42k nm at 15kts, I could see that she was shorter legged. :)
The H-class got a seakeeping of 1,26 at 28kts for the record ;)
QuoteAnd next tech level I'll take another crack at giving them armor, and won't that be fun? ^_^
Depends...
But i think my verdict on this class is either "decent" or "useless" (harsh i know) depending on what function doctrine gives her. As a battleline escort, picket ship and screening ship for capital ships she is decent (more guns would be nice for that role however), but I think she lacks the speed for effective use in offensive torpedo attacks, 30kts is minimum for that IMO.
Also not that high speed has another advantage, higher acceleration, a 30kts DD is likely to go from cursing speed (say 10kts) to 20kts in about 2/3rd the time of a 28kt ship.
But i agree that she is a big step forward in Maori DD design.
QuoteDifference in doctrine then. As I (and the Netherlands) see it, guns are the primary weapon of a destroyer, and it primary purpose is to destroy the enemy equals, and cripple enemy cruisers.
Fighting like with like can work, but I don't think it's a very effective use of resources. Better to match the enemies weaknesses to your own strengths...
QuoteSpringsharp does not punish you for going flush deck. It punish you for going for a very fat hull for a destroyer, increas her length 9m and I suspect you would get a more capable ship.
Thing is, that was one of the things I tried. The first time it didn't work, but the second it did. Very strange...
QuoteBut i think my verdict on this class is either "decent" or "useless" (harsh i know) depending on what function doctrine gives her. As a battleline escort, picket ship and screening ship for capital ships she is decent (more guns would be nice for that role however), but I think she lacks the speed for effective use in offensive torpedo attacks, 30kts is minimum for that IMO.
A typical battleship has a top speed of between 22 and 24 knots, right? 28 is enough to hunt that. Any capital vessel too quick to catch up to at this point in history is going to be in the 'glass-jawed boondoggle' category, and easy meat for real warships.
Besides, if I seriously wanted to build a small, fast ship, I'd pin down the weight and hp numbers for my aero-steam plants and start installing
them in destroyers. The mods'd crucify me.
ETA: Whoops! Here's that new version I mentioned.
Dawn Under Heaven, Maori Destroyer laid down 1912
Displacement:
1,000 t light; 1,038 t standard; 1,227 t normal; 1,379 t full load
Dimensions: Length overall / water x beam x draught
333.09 ft / 328.08 ft x 29.53 ft x 9.84 ft (normal load)
101.52 m / 100.00 m x 9.00 m x 3.00 m
Armament:
3 - 4.72" / 120 mm guns in single mounts, 52.72lbs / 23.91kg shells, 1912 Model
Quick firing guns in deck mounts with hoists
on centreline, evenly spread
Aft Main mounts separated by engine room
Weight of broadside 158 lbs / 72 kg
Shells per gun, main battery: 150
6 - 17.7" / 450 mm above water torpedoes
Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.98" / 25 mm 0.12" / 3 mm 0.12" / 3 mm
Machinery:
Oil fired boilers, steam turbines,
Electric motors, 2 shafts, 16,565 shp / 12,357 Kw = 28.00 kts
Range 4,000nm at 14.00 kts
Bunker at max displacement = 341 tons
Complement:
103 - 134
Cost:
£0.130 million / $0.519 million
Distribution of weights at normal displacement:
Armament: 20 tons, 1.6 %
Armour: 4 tons, 0.4 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 4 tons, 0.4 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 558 tons, 45.5 %
Hull, fittings & equipment: 367 tons, 29.9 %
Fuel, ammunition & stores: 227 tons, 18.5 %
Miscellaneous weights: 50 tons, 4.1 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
427 lbs / 194 Kg = 8.1 x 4.7 " / 120 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.24
Metacentric height 1.2 ft / 0.4 m
Roll period: 11.4 seconds
Steadiness - As gun platform (Average = 50 %): 100 %
- Recoil effect (Restricted arc if above 1.00): 0.59
Seaboat quality (Average = 1.00): 1.63
Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.451
Length to Beam Ratio: 11.11 : 1
'Natural speed' for length: 18.11 kts
Power going to wave formation at top speed: 60 %
Trim (Max stability = 0, Max steadiness = 100): 61
Bow angle (Positive = bow angles forward): 5.00 degrees
Stern overhang: 3.28 ft / 1.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 19.69 ft / 6.00 m
- Forecastle (20 %): 14.76 ft / 4.50 m
- Mid (50 %): 13.12 ft / 4.00 m
- Quarterdeck (15 %): 13.12 ft / 4.00 m
- Stern: 13.12 ft / 4.00 m
- Average freeboard: 14.09 ft / 4.30 m
Ship tends to be wet forward
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 163.8 %
- Above water (accommodation/working, high = better): 107.5 %
Waterplane Area: 6,182 Square feet or 574 Square metres
Displacement factor (Displacement / loading): 80 %
Structure weight / hull surface area: 28 lbs/sq ft or 137 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 2.00
- Overall: 0.57
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is adequate
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable, can fire her guns in the heaviest weather
6 tons torpedoes
10 tons short-range wireless
9 tons miscellaneous weight
25 tons destroyer fire control
Quote from: Valles on May 05, 2008, 06:28:57 PM
Fighting like with like can work, but I don't think it's a very effective use of resources. Better to match the enemies weaknesses to your own strengths...
Really comes down to what one sees as ones strengths. Like matching ones strong destroyers against an enemy's weaker destroyers and cruisers. I think it is an effective use of recourses, at least compared to wasting on building cruisers for screening.
QuoteA typical battleship has a top speed of between 22 and 24 knots, right? 28 is enough to hunt that. Any capital vessel too quick to catch up to at this point in history is going to be in the 'glass-jawed boondoggle' category, and easy meat for real warships.
Would say that a DD cannot ever "hunt" a capital ship, "harass" seems to be a better word. ;)
But to rapidly close to an attack position, and survive, a ship needs all the speed one can get, as to do an successful attack the realistic range is at most 3km, much less if the ship in manoeuvring to avoid the attack.
Considering that the DKB seems to like to use capital ships single or in pairs, it seems likely that they will be able of independent manoeuvre in response to an torpedo attack.
QuoteReally comes down to what one sees as ones strengths. Like matching ones strong destroyers against an enemy's weaker destroyers and cruisers. I think it is an effective use of recourses, at least compared to wasting on building cruisers for screening.
Destroyers are innately fragile; "using" one is a weasel-word for "expending" it. Cruisers, on the other hand, can be built to swat them in droves and still preserve the resources spent on them for reuse later. Their relatively overpowering mass and firepower allows them to swat destroyers with relative ease, while their armor renders them immune to light guns and their hulls are small and agile enough to be poor torpedo targets.
QuoteWould say that a DD cannot ever "hunt" a capital ship, "harass" seems to be a better word.
Then what are we developing torpedoes for? ^_^
QuoteBut to rapidly close to an attack position, and survive, a ship needs all the speed one can get, as to do an successful attack the realistic range is at most 3km, much less if the ship in manoeuvring to avoid the attack.
A boat without armor isn't a ship, it's a weapon. Expendable by definition. That being given, the question becomes cost effectiveness and circumstances of application. High speed
costs, in design compromises and in either engine
mass or
purchase price. 28 knots isn't great, I admit freely. But it's stormproof and not too expensive to be spent, so it should be good enough.
QuoteConsidering that the DKB seems to like to use capital ships single or in pairs, it seems likely that they will be able of independent manoeuvre in response to an torpedo attack.
I'm not sure how likely that is to matter. Even if the DKB favors dispersed operations,
I don't. A single battleship coping with an entire opposing battleline
and its own weight in destroyers is in for a bad day no matter
what its tactical options, and in a fleet action they'll be more constrained.
The likelihood of the DKB operating two "raiding" capital ships against your Battleline is remote, as is the likelihood of your Battleline plus destroyers finding two such targets, so the combat doctrine is not really viable.
You won't risk your entire Fleet to catch two "raiders" (since this won't be 'Sink the Bismark' time) and thus leave the continent vulnerable to the "rest" of the Brandenburg Fleet. Also Brandenburg would not challenge your Fleet with only two capital ships if they are aware of your "group" defense tactics. Thus they will be able to conduct raids on shipping without worry of your Battleline and your Battleline will not be sent out in one wave to leave Maoria "defenseless" when the rest of the Brandeburg Navy arrives.
Since the likely DKB raiders will be the Battlecrusiers, you'll have to deal with their speed edge over the rest of the battleships, and their rather heavy amount of anti-torpedo boat/destroyer gun batteries. This combination kept the Swiss (and Middle Kingdom) torpedo boats from closing on just a single Battlecruiser in 1907.
We are in complete agreement about the DKB's likely intended tactics; that was sort of my point.
The presumption that 'raiding' will even be possible in a militarily-useful way strikes me as questionable, however. The same principles that prohibit the scattering of military assets apply to that which they guard - In wartime, unconvoyed trade is a blithering idiocy the Maori are not inclined to commit. That the DKB twins dictate relatively large convoys to allow the efficient use of their protectors is a tactical factor, but ultimately irrelevant to logistics or strategy.
As for the application of the battle line, let's look at it this way...
Option 1.) Both fleets stay home. There's some fencing, landing forces get chopped up whenever they come into reach, and the entire mess ends up pissing away lives and treasure without producing any kind of decision.
Option 2.) One fleet goes to the other's homeland and there's a decisive battle leaving one side crippled or destroyed. With mastery of the sea, the victor can then apply their full strength to an invasion, likely ultimately leading to an unconditional surrender. Outcome depends on which fleet wins, but probably has relatively low losses. Since I wouldn't start a war unless I was confident of fleet superiority, this is a 'good' ending for me.
Option 3.) Both fleets go to the others' homelands, shelling coastline industries and supporting invasion fleets. I have a slightly greater population, more and more defensible core ports, and considerably more defensive depth. This is expensive enough to be avoided if possible, but likely a win for me.
Option 4.) Allied nations get involved. Obnoxiously complicated and unpredictable.
Option 5.) Jutland-like battle. Both sides engage in a major fleet action, neither side wins and it ends up a relative draw with few ship losses on both sides. One side will claim a tactical victory while the other will claim a strategic victory. Post-battle all nations will rethink their naval design theories.
QuoteOption 5.) Jutland-like battle. Both sides engage in a major fleet action, neither side wins and it ends up a relative draw with few ship losses on both sides. One side will claim a tactical victory while the other will claim a strategic victory. Post-battle all nations will rethink their naval design theories.
The purpose of battle is decision. '5' is innately a transient state of affairs on the way to one of the other, previously described scenarios.
Jutland itself, I think, was a 'worst case 1', which lead to the 'clash of armies' seen in 3 without the combined arms assumption. Since Maoria and DKB are more distant from each other than Britain and Germany, and lack a convenient land battlefield to clash on outside their homelands, an equivalent situation is unlikely.
Anyway. I got to experimenting with possible results of the 'throw-away destroyer' logic I mentioned. Take a look...
For Every Name, Maori Destroyer laid down 1912
Displacement:
500 t light; 520 t standard; 574 t normal; 617 t full load
Dimensions: Length overall / water x beam x draught
233.97 ft / 229.66 ft x 22.97 ft x 8.20 ft (normal load)
71.31 m / 70.00 m x 7.00 m x 2.50 m
Armament:
2 - 4.72" / 120 mm guns in single mounts, 52.72lbs / 23.92kg shells, 1912 Model
Quick firing guns in deck mounts
on centreline ends, evenly spread
Weight of broadside 105 lbs / 48 kg
Shells per gun, main battery: 150
3 - 17.7" / 450 mm above water torpedoes
Machinery:
Oil fired boilers, steam turbines,
Direct drive, 1 shaft, 12,786 shp / 9,538 Kw = 28.00 kts
Range 2,500nm at 12.00 kts
Bunker at max displacement = 97 tons
Complement:
58 - 76
Cost:
£0.068 million / $0.270 million
Distribution of weights at normal displacement:
Armament: 13 tons, 2.3 %
Machinery: 279 tons, 48.6 %
Hull, fittings & equipment: 193 tons, 33.6 %
Fuel, ammunition & stores: 74 tons, 13.0 %
Miscellaneous weights: 15 tons, 2.6 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
184 lbs / 84 Kg = 3.5 x 4.7 " / 120 mm shells or 0.2 torpedoes
Stability (Unstable if below 1.00): 1.22
Metacentric height 0.8 ft / 0.2 m
Roll period: 10.8 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.37
Seaboat quality (Average = 1.00): 1.23
Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0.465
Length to Beam Ratio: 10.00 : 1
'Natural speed' for length: 15.15 kts
Power going to wave formation at top speed: 70 %
Trim (Max stability = 0, Max steadiness = 100): 57
Bow angle (Positive = bow angles forward): 3.00 degrees
Stern overhang: 3.28 ft / 1.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 19.69 ft / 6.00 m
- Forecastle (20 %): 16.40 ft / 5.00 m
- Mid (50 %): 16.40 ft / 5.00 m (8.20 ft / 2.50 m aft of break)
- Quarterdeck (15 %): 8.20 ft / 2.50 m
- Stern: 8.20 ft / 2.50 m
- Average freeboard: 12.57 ft / 3.83 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 177.1 %
- Above water (accommodation/working, high = better): 92.3 %
Waterplane Area: 3,253 Square feet or 302 Square metres
Displacement factor (Displacement / loading): 50 %
Structure weight / hull surface area: 23 lbs/sq ft or 115 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 4.50
- Overall: 0.62
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is adequate
Ship has slow, easy roll, a good, steady gun platform
Good seaboat, rides out heavy weather easily
5 tons visual range wireless
6 tons torpedoes
4 tons misc weight
Quote from: Valles on May 05, 2008, 08:54:32 PM
Destroyers are innately fragile; "using" one is a weasel-word for "expending" it. Cruisers, on the other hand, can be built to swat them in droves and still preserve the resources spent on them for reuse later. Their relatively overpowering mass and firepower allows them to swat destroyers with relative ease, while their armor renders them immune to light guns and their hulls are small and agile enough to be poor torpedo targets.
Well, at the typical engagement range for destroyers, the 12cm guns are able to penetrate most cruisers armour with SAP shells in return (penetration of around 10cm at about 5km and 75mm at around 7km). This put the cruiser in the nice position of being a slower, larger and more expensive ship without much gains in combat value (if any, as it is slower). :)
QuoteQuoteWould say that a DD cannot ever "hunt" a capital ship, "harass" seems to be a better word.
Then what are we developing torpedoes for? ^_^
Well, to harass heavier ships!
But my point is that unless one got plenty of speed to rapidly get into a good attack position, the time spent under fire will make any massed toped attack against manoeuvring ship a sure one-way trip, if one seeks to hit with the torpedoes.
QuoteA boat without armor isn't a ship, it's a weapon. Expendable by definition. That being given, the question becomes cost effectiveness and circumstances of application. High speed costs, in design compromises and in either engine mass or purchase price. 28 knots isn't great, I admit freely. But it's stormproof and not too expensive to be spent, so it should be good enough.
Well i disagree there, armour that is not enough to give good protection against the likely shells is just a liability.
But really, the problem with the ship as I see it is that it is not very good for either role. At 28knots she will have increasingly hard to close with modern capital ships, and she does lack the firepower to overcome opposing equals.
Sure speed costs, there is no free lunch, but in a ship intended for offensive attacks, high closing speed makes the attack more likely to succeed, and allows the ship more chance to get away, so making the ship more survivable.
QuoteI'm not sure how likely that is to matter. Even if the DKB favors dispersed operations, I don't. A single battleship coping with an entire opposing battleline and its own weight in destroyers is in for a bad day no matter what its tactical options, and in a fleet action they'll be more constrained.
Not if they got the speed to avoid combat, and then jump on stragglers... At least that is one tactical option, and could be used to attempt to pin a larger enemy formation in place.
28kts should be compared to the 23+ kts speed of DKB dreadnoughts. I.e. not enough.
'Faster, faster!' ...feh.
Y'all're really trying to encourage me to get creative, aren't you?
Okay. Going on the theory that multiple motors can feed the same electric generator, and that engines meant for airborne use weigh about four pounds per hp, and that outriggers give seakeeping and stability as would a hull of their total width, we get...
Nor Iron Bars, Maori Destroyer laid down 1912
Displacement:
267 t light; 283 t standard; 333 t normal; 373 t full load
Dimensions: Length overall / water x beam x draught
201.48 ft / 196.85 ft x 16.40 ft x 6.56 ft (normal load)
61.41 m / 60.00 m x 5.00 m x 2.00 m
Armament:
2 - 4.72" / 120 mm guns in single mounts, 52.72lbs / 23.92kg shells, 1912 Model
Quick firing guns in deck mounts with hoists
on centreline ends, evenly spread
Weight of broadside 105 lbs / 48 kg
Shells per gun, main battery: 150
4 - 17.7" / 450 mm above water torpedoes
Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.98" / 25 mm 0.12" / 3 mm -
Machinery:
No fuel, Internal combustion motors,
Electric motors, 2 shafts, 13,780 shp / 10,280 Kw = 30.00 kts
Range 5,000nm at 10.00 kts
Bunker at max displacement = 91 tons
Complement:
38 - 50
Cost:
£0.020 million / $0.082 million
Distribution of weights at normal displacement:
Armament: 13 tons, 4.0 %
Armour: 3 tons, 0.9 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 3 tons, 0.9 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 0 tons, 0.0 %
Hull, fittings & equipment: 156 tons, 46.9 %
Fuel, ammunition & stores: 66 tons, 19.8 %
Miscellaneous weights: 95 tons, 28.5 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
161 lbs / 73 Kg = 3.1 x 4.7 " / 120 mm shells or 0.1 torpedoes
Stability (Unstable if below 1.00): 1.35
Metacentric height 2.9 ft / 0.9 m
Roll period: 12.1 seconds
Steadiness - As gun platform (Average = 50 %): 75 %
- Recoil effect (Restricted arc if above 1.00): 0.05
Seaboat quality (Average = 1.00): 1.51
Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.550
Length to Beam Ratio: 12.00 : 1
'Natural speed' for length: 14.03 kts
Power going to wave formation at top speed: 76 %
Trim (Max stability = 0, Max steadiness = 100): 52
Bow angle (Positive = bow angles forward): 5.00 degrees
Stern overhang: 3.28 ft / 1.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 15.42 ft / 4.70 m
- Forecastle (20 %): 9.81 ft / 2.99 m
- Mid (50 %): 9.81 ft / 2.99 m
- Quarterdeck (15 %): 9.81 ft / 2.99 m
- Stern: 9.81 ft / 2.99 m
- Average freeboard: 10.26 ft / 3.13 m
Ship tends to be wet forward
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 62.2 %
- Above water (accommodation/working, high = better): 114.5 %
Waterplane Area: 2,254 Square feet or 209 Square metres
Displacement factor (Displacement / loading): 164 %
Structure weight / hull surface area: 25 lbs/sq ft or 124 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 6.46
- Overall: 0.65
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is adequate
Ship has a slow,easy roll, a good, steady gun platform
Excellent seaboat, comfortable, can fire her guns in the heaviest weather
30 tons 14,000 hp aero engines
25 tons destroyer fire control
10 tons port ama
10 tons starboard ama
10 tons short-range wireless
4 tons torpedoes
6 tons misc weight
I have no idea what to say about that...
You got no weight for the electric engine itself, just the generators. I suspect the engine itself will be quite heavy.
A 1925 electric locomotive weight in at 80 tons, and that one have an 1840kW engine. It seems reasonable to assume that maybe ¼ of the weight of the locomotive is the engine itself (wild guess, but seems reasonable), that would put the electric motors for the close to 11 000kW you want in the destroyer close to a hefty 120 tons. :(
I think that is the reason F1 cars do not have electric engines.
How do you think it would look to mount the engines along the booms to the outriggers, and have one propeller each, like a huge rack of outboard engines?
Hm. Well, one advantage to my using lightweight steam engines rather than IC is that they're more scalable at this point in history... but it seems kinda unsporting to play up that aspect when I'm already doing so much utterly weird shit.
Ah, well. Cross-linked direct drive systems do exist (a la V-22 Osprey), and I'd always intended that the airships used direct drive shafts from a single centrally mounted engine...
QuoteMachinery:
No fuel, Internal combustion motors,
Electric motors, 2 shafts, 13,780 shp / 10,280 Kw = 30.00 kts
Range 5,000nm at 10.00 kts
Bunker at max displacement = 91 tons
So what, they run on trash or something? Where did you put the flux capacitor? :D
That would qualify as my not correcting a weird artifact of SS. ^_^ The fuel is something about like kerosene or jet fuel - a dense, hot-burning petroleum derivative more filtered and refined than conventional steam-plant fuel oil.
Have you calculated the wave resistance of the two outriggers? :P
Quote from: Valles on May 08, 2008, 11:27:13 AM
That would qualify as my not correcting a weird artifact of SS. ^_^ The fuel is something about like kerosene or jet fuel - a dense, hot-burning petroleum derivative more filtered and refined than conventional steam-plant fuel oil.
Like "super-diesel"? How did you sim fuel weight in the SS Report?
QuoteDistribution of weights at normal displacement:
Armament: 13 tons, 4.0 %
Armour: 3 tons, 0.9 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 3 tons, 0.9 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 0 tons, 0.0 %
Hull, fittings & equipment: 156 tons, 46.9 %
Fuel, ammunition & stores: 66 tons, 19.8 %
Miscellaneous weights: 95 tons, 28.5 %
No Machinery weight? And that 66t for "Fuel, ammunition & stores" is ammunition & stores in this case.
Quote from: Sachmle on May 08, 2008, 12:47:07 PM
And that 66t for "Fuel, ammunition & stores" is ammunition & stores in this case.
But SS states that "Bunker at max displacement = 91 tons".
Seems that some fuel is included.
Now that's just weird.
Very weird...
Hm. Lemme try it with SS3.
Ooh. New version has 'relative weight performance' slider for engines. Doesn't work yet, though, pity. 'Calculate speed for power', ditto and ditto.
Ah, well, that's no good. This version doesn't work even as well as the last.
Anyway. Things like this and hydrofoils are on my list of 'to be developed later' items.
As to 'outrigger drag', no, I've not done anything with that. Would be a lot of very thorny math, there, and, while I'm willing to go to the trouble if I'd actually be allowed to build the nightmare things, I don't actually know how.
The simplest, somewhat crude way is to simulate the outriggers as separate ships - length, beam, draught, BC speed would give you a power requirement that you need. Only first approximation, of course.
But then, then the same outriggers would influence stability too much, and comes the question that what size of outriggers you need for a given ship.
...
Selecting no fuel apparently makes SS2 think the engine is missing.
That was the idea, since SS's engines are all an order of magnitude or so heavier than what I had available to install on the ship.
So I guess we need to resolve four broad questions:
-How do we accurately simulate an outrigger with SS?
-Is an outrigger of this size and speed technologically possible in our time period?
-How do we accurately simulate the machinery set-up?
-Is the machinery set-up feasible and technologically possible?
Quote from: The Rock Doctor on May 08, 2008, 04:17:35 PM
So I guess we need to resolve four broad questions:
-How do we accurately simulate an outrigger with SS?
-Is an outrigger of this size and speed technologically possible in our time period?
-How do we accurately simulate the machinery set-up?
-Is the machinery set-up feasible and technologically possible?
- Outrigger cannot be simulated by SS only. Extra SHP need yes, stability/steadiness no.
- Without any naval engineering background I cannot tell how large outriggers have to be to be effective. It should be mention, that the additional resistance of two outriggers would make a trimaran slower than a monohull of the same displacement. The usual problems of SS2 and small fast hulls is still there.
- machinery set-up cannot be simulated by SS2.
- without electric motors, yes. Of course you need adequate engine technology.
Would you really WANT one? What happens to performance when one of the outriggers is damaged by shellfire/torpedo/mine? Will the ship still be stable enough to be useful? How much damage could an outrigger sustain?
I don't think that convincing Springsharp to do something with more than the vaguest resemblance to the proposed layout and performance is possible without cutting and pasting together two or three different sims... which was what I did. I suspect that a multihull that suffered a sudden increase in drag on one of its outriggers (as for a hit below the waterline) or a sudden loss of structural strength (ditto for a bracing arm) at speed would rip itself apart quite messily. On the other hand, they are immensely stable for their weight and they're mostly empty space, so the odds of that happening aren't actually all that bad.
My choosing a trimaran layout for this design had much more to do with the fact that SS2 puts all misc weight above the waterline than with my interest in having a multihull. I tripled the beam to account for the outrigger's positioning, grabbed the stability figures, and then dropped them into the original sim.
If I were to try and create something like this that I was serious about building, it'd probably be a relatively wide single-hull - a true planing design rather than a displacement hull.
But that would open its own can of worms, of course.
I had a brainstorm that resurrected this unholy evil of a concept.
Namely, that it'd probably be considered wise to have a more conventional, cheaper cruising engine that could be entered into SS as the 'primary' engine to get an accurate read on the resulting boat's steadiness and stability. The aero engine would be entered under misc weight and the top speed tweaked in the design process to get a 'combat seakeeping', which could then be included under the 'notes' section. Each engine would either drive different props or require Geared Drives to be able to switch between them.
Reasonable?
Quote from: Valles on May 12, 2008, 02:45:01 PM
I had a brainstorm that resurrected this unholy evil of a concept.
Namely, that it'd probably be considered wise to have a more conventional, cheaper cruising engine that could be entered into SS as the 'primary' engine to get an accurate read on the resulting boat's steadiness and stability. The aero engine would be entered under misc weight and the top speed tweaked in the design process to get a 'combat seakeeping', which could then be included under the 'notes' section. Each engine would either drive different props or require Geared Drives to be able to switch between them.
Reasonable?
Just how small a ship are you talking about, 100tons or as large as 200?
The reason i am asking is that with areo engines limited to 120hp, you need a very small boat to make them an improvment in speed. :)
But considering the hp limits we got on all engines, I do not really see this as reasonable. While we should not follow history like slaves, it is worth to ask oneself why no one tried mounting aircraft-style engines in ships of any size, it might be that there are physical reason that makes that sort of engines unsuited to ship propulsion.
Ever wonder why no one ever did this in RL? Probably because it's an inherently bad idea. I don't have a problem w/ originality, but seriously this is a little overboard.
Alexander Bell did, with a hydrof...err speed boat no less!
Now to begin work on that hyrdofoil...
A hydroplane is one thing, a 100-200t TB is another. Maybe if we were talking MTBs here, but a TB?
Or if this topic was Maori DE-1943.
Quote from: Valles on May 12, 2008, 02:45:01 PM
I had a brainstorm that resurrected this unholy evil of a concept.
Namely, that it'd probably be considered wise to have a more conventional, cheaper cruising engine that could be entered into SS as the 'primary' engine to get an accurate read on the resulting boat's steadiness and stability. The aero engine would be entered under misc weight and the top speed tweaked in the design process to get a 'combat seakeeping', which could then be included under the 'notes' section. Each engine would either drive different props or require Geared Drives to be able to switch between them.
Reasonable?
Umm... No? IMO the easiest and best is to have separate tech for (M)TBs that have fixed characteristics to overcome SS2 limitations - similar to the sub techs. Also, the lack of any naval engineering experience on the forum (AFAIK) is a big obstacle in the way of multihulls.
The main advantage of a trimaran that it have shallower draught, and the main hull can be longer without much regard to stability consequences - at the cost of larger waterplane area thus resistance, and additional structural weight - the outriggers and the extra weight of the sponsons. Also, a trimaran would not right itself, so storms that can be survived by a destroyer might cause a trimaran to capsize.
And we have the complete lack of historical steel (or even wood) high-speed trimarans for this time period.
It's rather amusing how much harsher the responses get as I start to get more serious about this concept. ^_^
Anyway, I'm talking 'full sized destroyer' for the moment, very much like a refinement of the multi-hull design on the previous page of the thread. A number of cruise and military ship designers in the present day think that a very similar arrangement is quite a good idea, I'm given to understand. Real world designers in the nineteen-teens likely never considered such a thing because they'd never been so crazy as to try and develop steam engines light enough to drive an airship and so were limited to, as noted, about 120 additional horsepower.
And, no, P3D, I'm not intending to build a 'combination powerplant' into a multihull - having the heavier cruising engine would give sufficient stability in its own right to render the outriggers unnecessary.
I do like the idea of separately researched MTBs, though.
Quote from: Valles on May 12, 2008, 04:56:48 PM
It's rather amusing how much harsher the responses get as I start to get more serious about this concept. ^_^
Anyway, I'm talking 'full sized destroyer' for the moment, very much like a refinement of the multi-hull design on the previous page of the thread. A number of cruise and military ship designers in the present day think that a very similar arrangement is quite a good idea, I'm given to understand. Real world designers in the nineteen-teens likely never considered such a thing because they'd never been so crazy as to try and develop steam engines light enough to drive an airship and so were limited to, as noted, about 120 additional horsepower.
And, no, P3D, I'm not intending to build a 'combination powerplant' into a multihull - having the heavier cruising engine would give sufficient stability in its own right to render the outriggers unnecessary.
I do like the idea of separately researched MTBs, though.
XIXth century engineers were much crazier than you'd think. E.g. there were about a dozen attempt to build a rotary steam engine that I know of - Parsons himself had some before finally arriving at the turbine.
Again, this could be solved by variable engine specific power. Even so, contemporary large IC engines were heavy, and airship engines were far from the power requirements. So a 14000SHP diesel would weight more than 30t. And forget about electric propulsion, that would add so much to the weight (another 60+t for the power) that any weight savings from the lightweight IC engines would disappear. And the adequate I engine technology still needs to be developed.
Does anyone have some weight figures on airship engines?
I spent a few very frustrating hours trying to research airship engines before I went and expanded on the power/weight ratio of WWI fighter engines; no joy.
I was on a big 'the world can be saved by STEAM' kick when I put together my 'application for' tech tree for the Maori, though, so their airships are designed to use central steam engines throwing shafts off to multiple propellers, rather than having several engines like real world rigids did. I haven't had occasion to build any new ones, yet, but I've been planning to add $0.1 per engine to my airship building costs to account for the exotic materials (in 191X, titanium is exotic) needed to build their engines; whatever ships or boats get built using the same technology would have at least that much added. I've been consistently rounding numbers up from my base 500 hp/ton guesstimate, also.
Titanium is too difficult to manufacture (just ask maddox).
Pure metallic Ti was first produced in 1910, and practical uses are still several decades of materials research away (historically, after WWII). IMO It does not offer much advantage over some advanced ferrous materials.
Scaling up high RPM aircraft engines is not a good way to estimate power-to-weight ratios. As engines grow, max RPM decreases (due to the combustion speed of the fuel-air mixture), with it the power output. Using diesel instead of gasoline/petrol makes the engine even more heavier.
500HP/t is the Maybach HL230 of the Tiger. Petrol engine, 1200kg for 600HP(sustained).
I will do some SS to see if i can get some enigne weight estimate for Italian MAS.
I simmed hulls for MAS and S-boats, then increased engines to get a composite strength of 0.8-0.9. Also added some arbitrary misc weight for guns torpedoes etc.
MAS 204 (1918) had 2x700HP engines. Engine weight comes at ~5-6t, giving 2-300HP/t. MAS 432 has 3x1500HP engines - the engine power-to-weight corresponds well to aircraft engines (1000HP/t).
Looking at medium-power marine engines (2500HP) for the larger Schnellbooten, power-to-weight ratio is somewhere between 150 and 200HP/ton (let's say 200). Compare it to 50-60SHP/t for the German battleships' high-pressure steam machinery in WWII, 30-40 for large marine diesels, or RN destroyer machinery (essentially constant at 80-90 SHP/ton between 1914 and 1942).