WesWorld

Quoted

Originally posted by Jefgte
170 tons for deck operations facilities - ext bridge poles

What do you mean by "ext bridge poles"?

Quoted

What do you mean by "ext bridge poles"?

This is an arrangement of metal poles outside the bridge to put the tails of the aircrafts outside the flyingdeck.

Jef

Hum. Did anyone ever do that historically?

Looking at that DD, I don't see how it is an improvement over the class you are aiming to replace. What is your reasoning behind the gun choices?

Quoted

Originally posted by Brockpaine
Hum. Did anyone ever do that historically?

The RN did, I want to say several others did as well.

Quoted

Originally posted by eltf177

Quoted

Originally posted by Brockpaine
Hum. Did anyone ever do that historically?

The RN did, I want to say several others did as well.

I have not had luck finding pictures, do you have any?

I will raise my hand again on the question of carrying a twin 152mm turret, and barbette, on a vessel with only 14-metres beam and such a sharp bloc coefficient. I could be convinced of a deck mount maybe - but a full barbette seems asking an awful lot.

This vessel also looks like a "pocket cruiser" rather than a destroyer. Just saying...

The Japansese Yubari class CL had a beam of 12,04m and the Dutch Tromp class CL a beam of 12,4m.

So a twin 15cm deck mount should not be an issue - but barbets are more difficult.

The USN Omahas had a beam of 16,87m, the IJN Agano 15,19m, the RN Arethusas had 17m, the RN Emeralds 16,6m, Italian Da Barbiano offered 15,5m - all featuring 15cm twin turrets.

However, the French put a 6" triple on 15,77m on the Emile Bertin and the Germans 15cm triples on 15,2m on the K-class CLs. The latter mounts were even offset from the centerline aft. The Japanese put much larger 8in twins on the Furutuka, a design of 16,51m beam. All of these designs were not known for their ruggedness, though.

Finally, the German destroyers of the Typ 36 class deserve a note. On a beam of 12m they also carried twin 15cm mounts but these mouts were some kind of a mix between mount&hoist and true barbets.

In the end, personally, I think a 15cm twin turret on 14cm beam is possible.

In fact, we have precedence in WesWorld for design of less than 14m beam with 15cm twin turrets on barbets - the ex-RSAN Alswinn class coastal defense vessels for example (12,5m). The drawing indicates there is enough space for such weapon as the turrets are drawn to the look and dimensions of the 15,5cm twins on the French Duguay Trouin class. And I am sure there are other examples of WesWorld designs that fit the category....

There is a bigger problem than the 15cm turrets, what about the four twin 105mm beam mounts (also simmed as turrets) on a 14m ship!
Although around 2m wider than most of the biggest destroyers of the period, if you look at, say a Tribal or a Gearing, there is no way you could fit sided mounts on that hull. Adding the six quad 37mm and six quad 25mm I don't think its feasible to fit the ten 21in torpedoes (I assume 2x5 mounts) aboard. There just isn't enough deck space.
I've never though the Italian 152mm DP mount to be worthwhile given the slower RoF despite the larger shell weight. Really 4x2 105mm would be better for AA.

Re: the ext poles, yes the RN used them but I don't think a couple of steel girders are going to eat up 170 tons. But again, it shows how constrained the carrier design is.

It's just odd how you've made the destroyer too big and wasted so much tonnage yet the carrier is too small and has not enough tonnage.

I agree with Hood - some real space issues here.

Indeed.

I had focused on the beam/barbet thing only in my first post but given all the armament I really do not see what the deck layout would look like to enable good arcs for all.

Jefgte, can you provide a drawing?

Quoted

Originally posted by HoOmAn
I had focused on the beam/barbet thing only in my first post but given all the armament I really do not see what the deck layout would look like to enable good arcs for all.

I'm envisioning something in a hex layout, like an old predreadnought. This kinda seems to be the destroyer version of a predreadnought...

HooMan, I agree
A study drawing is neccessary to validate the concept

Jef

Quoted

Originally posted by Jefgte

Quoted

You're going to have problems operating jets off those small decks, Jef.

WW finish in 1950, so jets are not realy a priority.
However, aircraft increase in size & weight.
SS on a 195m hull could be useful to carry bigger planes.

Jef

I will reiterate what I just said in another thread; this rumor refuses to die, but it remains just that; a rumor.

Springsharp lay-down dates end at 1950, but that does not mean rules (or a new program) cannot be developed to overcome that issue.

Regardless, even if the sim ends in 1950...that is a wholly Out-of-character issue. Your governments and designers absolutely should not be approaching their plans with the mindset of "This world ceases to exist on 1 January 1950, so don't care about anything that isn't done before then"

Peru could built 4 x 4 x 200t Defender per year.

200t-Defender, Peru MineSweeper-SubChasser- Escort laid down 1944

Displacement:
200 t light; 216 t standard; 248 t normal; 273 t full load

Dimensions: Length overall / water x beam x draught
153.85 ft / 147.64 ft x 22.64 ft x 5.84 ft (normal load)
46.89 m / 45.00 m x 6.90 m x 1.78 m

Armament:
2 - 4.13" / 105 mm guns in single mounts, 35.32lbs / 16.02kg shells, 1944 Model
Quick firing guns in deck mounts
on centreline, evenly spread
8 - 0.98" / 25.0 mm guns (4x2 guns), 0.48lbs / 0.22kg shells, 1944 Model
Machine guns in deck mounts
on side, evenly spread
Weight of broadside 74 lbs / 34 kg
Shells per gun, main battery: 250
3 - 17.7" / 450 mm above water torpedoes

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.59" / 15 mm - -
2nd: 0.59" / 15 mm - -

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 1 shaft, 1 940 shp / 1 448 Kw = 20.00 kts
Range 2 500nm at 15.00 kts
Bunker at max displacement = 58 tons

Complement:
30 - 40

Cost:
£0.146 million / $0.585 million

Distribution of weights at normal displacement:
Armament: 9 tons, 3.8 %
Armour: 3 tons, 1.3 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 3 tons, 1.3 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 50 tons, 20.0 %
Hull, fittings & equipment: 88 tons, 35.4 %
Fuel, ammunition & stores: 48 tons, 19.3 %
Miscellaneous weights: 50 tons, 20.2 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
225 lbs / 102 Kg = 6.4 x 4.1 " / 105 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.10
Metacentric height 0.6 ft / 0.2 m
Roll period: 11.9 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.36
Seaboat quality (Average = 1.00): 1.41

Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0.444
Length to Beam Ratio: 6.52 : 1
'Natural speed' for length: 14.51 kts
Power going to wave formation at top speed: 68 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 17.06 ft / 5.20 m
- Forecastle (20 %): 14.76 ft / 4.50 m
- Mid (50 %): 14.76 ft / 4.50 m (6.89 ft / 2.10 m aft of break)
- Quarterdeck (18 %): 6.89 ft / 2.10 m
- Stern: 6.89 ft / 2.10 m
- Average freeboard: 11.01 ft / 3.36 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 117.7 %
- Above water (accommodation/working, high = better): 83.8 %
Waterplane Area: 2 204 Square feet or 205 Square metres
Displacement factor (Displacement / loading): 109 %
Structure weight / hull surface area: 20 lbs/sq ft or 97 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 6.63
- Overall: 0.65
Caution: Hull subject to strain in open-sea
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is cramped
Ship has slow, easy roll, a good, steady gun platform
Good seaboat, rides out heavy weather easily

20 tons Mines chasser + 30 tons DC

I believe that the proposed design runs afoul of the Design Rules for Gentlemen - the Gents Rules - which can be found in the Rules and Admin Folder.

Quoted

Point 1: Hull strength.
a) Relative composite hull strength should not drop below 1.00 except for the light fast combattants (<6000 tons standard; >24kn)
b) Relative cross-sectional hull strength of light fast combattants of 0-3,000 tons standard should not drop below 0.5
c) In general, light fast combattants of 3,001-4,500 tons standard can have a minimum relative composite hull strength of 0.75 as long as it does not cross the limit as given in point 1b.
d) In general, light fast combattants between 4500 tons and 6000 tons standard can have a minimum relative composite hull strength of 0.9

Presuming that the design is subject to these rules - there could be leeway for small vessels - the proposed design lacks sufficient strength and does not have the speed to qualify as a light fast combatant.

Secondly, I find the provision of two 105mm guns on such a small hull questionable. Historical vessels of this size usually limited themselves to guns in the 3-in range.

Rather than steam turbines, diesel engines would make far more sense for a powerplant.

Bruce is correct on the issue of hull strength.

Hmmmm...

Not sure about the possibility to SS a µDD
with 200t & 24kts...

Jef

Quoted

Originally posted by Jefgte
Hmmmm...

Not sure about the possibility to SS a µDD
with 200t & 24kts...

Jef

Perhaps not, but with the Mehrzweckboote 40 I was able to get close. It can be done, though it requires fine balancing.

The armament fit proposed for your design is far too heavy for such a small hull.

200t shipyards are just able to built MTBS, Schnellboot or patrol craft.
So, Peru built MTBS in that shipyards.
200t µDD had µ performances...

Most serious & able to work near the harbours & coasts, Defender class is heavily armed for the displacement & could be considered as a µDD.

290t-Defender, Peru MineSweeper-SubChasser- Escort laid down 1944

Displacement:
290 t light; 322 t standard; 368 t normal; 405 t full load

Dimensions: Length overall / water x beam x draught
182.57 ft / 176.84 ft x 22.97 ft x 7.48 ft (normal load)
55.65 m / 53.90 m x 7.00 m x 2.28 m

Armament:
4 - 4.13" / 105 mm guns (2x2 guns), 35.32lbs / 16.02kg shells, 1944 Model
Quick firing guns in deck mounts
on centreline, evenly spread
8 - 0.98" / 25.0 mm guns (4x2 guns), 0.48lbs / 0.22kg shells, 1944 Model
Machine guns in deck mounts
on side, evenly spread
Weight of broadside 145 lbs / 66 kg
Shells per gun, main battery: 300
3 - 17.7" / 450 mm above water torpedoes

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.59" / 15 mm - -
2nd: 0.59" / 15 mm - -

Machinery:
Diesel Internal combustion motors,
Geared drive, 2 shafts, 4 737 shp / 3 534 Kw = 24.00 kts
Range 3 000nm at 15.00 kts
Bunker at max displacement = 83 tons

Complement:
41 - 54

Cost:
£0.268 million / $1.071 million

Distribution of weights at normal displacement:
Armament: 18 tons, 4.9 %
Armour: 5 tons, 1.4 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 5 tons, 1.4 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 103 tons, 28.0 %
Hull, fittings & equipment: 114 tons, 31.0 %
Fuel, ammunition & stores: 79 tons, 21.3 %
Miscellaneous weights: 49 tons, 13.3 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
162 lbs / 73 Kg = 4.6 x 4.1 " / 105 mm shells or 0.2 torpedoes
Stability (Unstable if below 1.00): 1.05
Metacentric height 0.6 ft / 0.2 m
Roll period: 12.4 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.56
Seaboat quality (Average = 1.00): 1.01

Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.424
Length to Beam Ratio: 7.70 : 1
'Natural speed' for length: 15.68 kts
Power going to wave formation at top speed: 71 %
Trim (Max stability = 0, Max steadiness = 100): 69
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 15.75 ft / 4.80 m
- Forecastle (20 %): 12.47 ft / 3.80 m
- Mid (50 %): 9.19 ft / 2.80 m
- Quarterdeck (18 %): 8.53 ft / 2.60 m
- Stern: 8.53 ft / 2.60 m
- Average freeboard: 10.37 ft / 3.16 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 146.4 %
- Above water (accommodation/working, high = better): 76.6 %
Waterplane Area: 2 636 Square feet or 245 Square metres
Displacement factor (Displacement / loading): 83 %
Structure weight / hull surface area: 22 lbs/sq ft or 108 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 3.91
- Overall: 0.61
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is cramped
Ship has slow, easy roll, a good, steady gun platform

20 tons Mines chasser + 29 tons DC