WesWorld

Vakt Class, Gothia Works Destroyer laid down 1935

Displacement:
2 940 t light; 3 076 t standard; 3 337 t normal; 3 546 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(446,05 ft / 442,91 ft) x 45,93 ft x (16,40 / 17,01 ft)
(135,96 m / 135,00 m) x 14,00 m x (5,00 / 5,18 m)

Armament:
6 - 5,91" / 150 mm 45,0 cal guns - 103,86lbs / 47,11kg shells, 150 per gun
Breech loading guns in Coles/Ericsson turret mounts, 1935 Model
2 x 2-gun mounts on centreline, evenly spread
1 x 2-gun mount on centreline ends, evenly spread
1 raised mount
Aft Main mounts separated by engine room
16 - 1,57" / 40,0 mm 45,0 cal guns - 1,97lbs / 0,89kg shells, 1 000 per gun
Anti-air guns in deck mounts, 1935 Model
8 x 2-gun mounts on sides, evenly spread
Weight of broadside 655 lbs / 297 kg

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 2,00" / 51 mm 310,04 ft / 94,50 m 8,13 ft / 2,48 m
Ends: 1,00" / 25 mm 132,85 ft / 40,49 m 8,13 ft / 2,48 m
Upper: 1,00" / 25 mm 310,04 ft / 94,50 m 8,00 ft / 2,44 m
Main Belt covers 108 % of normal length
Main belt does not fully cover magazines and engineering spaces

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1,50" / 38 mm - -

- Armoured deck - multiple decks: 0,50" / 13 mm For and Aft decks
Forecastle: 0,50" / 13 mm Quarter deck: 0,50" / 13 mm

- Conning towers: Forward 2,00" / 51 mm, Aft 0,00" / 0 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 57 668 shp / 43 020 Kw = 34,00 kts
Range 4 000nm at 15,00 kts
Bunker at max displacement = 471 tons

Complement:
219 - 285

Cost:
£1,904 million / $7,616 million

Distribution of weights at normal displacement:
Armament: 186 tons, 5,6 %
Armour: 481 tons, 14,4 %
- Belts: 343 tons, 10,3 %
- Armament: 15 tons, 0,4 %
- Armour Deck: 113 tons, 3,4 %
- Conning Tower: 10 tons, 0,3 %
Machinery: 1 502 tons, 45,0 %
Hull, fittings & equipment: 771 tons, 23,1 %
Fuel, ammunition & stores: 398 tons, 11,9 %
Miscellaneous weights: 0 tons, 0,0 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
956 lbs / 434 Kg = 9,3 x 5,9 " / 150 mm shells or 0,5 torpedoes
Stability (Unstable if below 1.00): 1,40
Metacentric height 2,8 ft / 0,9 m
Roll period: 11,5 seconds
Steadiness - As gun platform (Average = 50 %): 40 %
- Recoil effect (Restricted arc if above 1.00): 0,29
Seaboat quality (Average = 1.00): 0,65

Hull form characteristics:
Hull has a flush deck,
a normal bow and a cruiser stern
Block coefficient (normal/deep): 0,350 / 0,359
Length to Beam Ratio: 9,64 : 1
'Natural speed' for length: 21,05 kts
Power going to wave formation at top speed: 60 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 12,00 degrees
Stern overhang: 0,00 ft / 0,00 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 15,00 %, 14,76 ft / 4,50 m, 13,12 ft / 4,00 m
- Forward deck: 35,00 %, 13,12 ft / 4,00 m, 13,12 ft / 4,00 m
- Aft deck: 35,00 %, 13,12 ft / 4,00 m, 13,12 ft / 4,00 m
- Quarter deck: 15,00 %, 13,12 ft / 4,00 m, 13,12 ft / 4,00 m
- Average freeboard: 13,22 ft / 4,03 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 162,7 %
- Above water (accommodation/working, high = better): 128,3 %
Waterplane Area: 12 147 Square feet or 1 128 Square metres
Displacement factor (Displacement / loading): 77 %
Structure weight / hull surface area: 46 lbs/sq ft or 223 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0,51
- Longitudinal: 0,89
- Overall: 0,54
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is excellent
Caution: Lacks seaworthiness - very limited seakeeping ability


Revised design


Comments welcome

I foresee a lot of people making comments regarding several features. Oh yes, I foresee those comments.... 8)

How can it be both at excessive risk of capsizing and an excellent seaboat?

Looks like some sort of bug.

Seaboat rating is mostly about height of gunwale, ie, how high the main deck is above the water. Capsizing is about stability, the two aren't the same thing (in SS2, anyway). More comments to come.

OK, here's some comments:

1 - I'm assuming it's an SS3 design, by some of the text. For a mid-1930s destroyer, the choice of 450mm torpedoes on side mounts is unusual, and probably dubious. The 450mm torpedoes simply are too small to carry enough explosive.

2 - Ammo load on the 40mms is WAY too low.

3 - The weight spent on torpedo bulkheads and bulges is a waste: the ship is too small to have enough breadth to use them and the effects are minimal (see the survivability section, the ship can withstand only 0.3 torpedoes).

4 - Top speed is pretty low for a large fleet destroyer, most others in this size range are reaching 35+ knots.

5 - Length to beam ratio is quite high, anything over about 11:1 is fairly suspect.

6 - She's unstable, prone to capsizing, and has recoil-restricted gun arcs for her main battery. This is because she's top heavy, with a 9 meter deck height all the way to the quarterdeck, along with upper belt armor.

7 - Range is pretty low for such a ship, even at a relatively high cruising speed. I'd recommend at least 3,000 miles, while 4,000 would be better.

8 - The belt armor, thin though it is, doesn't cover the engines and the magazines.

9 - By the sim rules (here http://wesworld.jk-clan.de/thread.php?threadid=2074&sid= ), it has some more problems - a ship of this size has to have a cross-sectional strength of at least 0.50, and a composite hull strength of at least 0.75.

Of course, none of this is unfixable. Lowering the main deck and ditching the torpedo defences will free up tonnage for strength improvements and more fuel, and will probably also result in better in-water behavior.

I add the seperated machinery space and the Ericsson-turrets. End belts?

I got a serious trouble with displacement, i can´t get a reasonable boat below 4000 tons, help

Define "reasonable". Take a look at the various Destroyers either in this section of the board, or in the various country encyclopedia entries. You're probably trying to do too much on the hull.

Even before I add armor & guns I get 4000-5000tons on a 120x13m hull

Like the design above many early attempts of newcomers have too much draught. 6m for a DD is way too much and with a reasonable block coefficient of ~0,4 leads to a large displacements.

Feel free to browse this thread to get some ideas what a 4000ts design might look like.

Thanks