WesWorld

This design is built as an coastal patrol, and escort by navy surplus weapons from scrapped older ships, only the 40mm AA is new.



K105, Sweden Gunboat laid down 1940

Displacement:
793 t light; 830 t standard; 855 t normal; 875 t full load

Dimensions: Length overall / water x beam x draught
268,89 ft / 262,47 ft x 39,37 ft x 9,84 ft (normal load)
81,96 m / 80,00 m x 12,00 m x 3,00 m

Armament:
2 - 5,98" / 152 mm guns (1x2 guns), 101,41lbs / 46,00kg shells, 1912 Model
Quick firing guns in a turret (on a barbette)
on centreline forward
8 - 1,57" / 40,0 mm guns (4x2 guns), 1,95lbs / 0,88kg shells, 1936 Model
Anti-aircraft guns in deck mounts
on side, all aft, 2 raised mounts - superfiring
8 - 0,31" / 8,0 mm guns (4x2 guns), 0,02lbs / 0,01kg shells, 1939 Model
Machine guns in deck mounts
on centreline, all amidships, all raised mounts - superfiring
Weight of broadside 219 lbs / 99 kg
Shells per gun, main battery: 150
4 - 18,0" / 457,2 mm above water torpedoes

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 0,59" / 15 mm 144,36 ft / 44,00 m 7,51 ft / 2,29 m
Ends: Unarmoured
Main Belt covers 85 % of normal length

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1,97" / 50 mm 0,98" / 25 mm 1,97" / 50 mm
2nd: 0,20" / 5 mm - -
3rd: 0,20" / 5 mm - -

- Armour deck: 0,20" / 5 mm, Conning tower: 0,59" / 15 mm

Machinery:
Diesel Internal combustion motors,
Geared drive, 2 shafts, 3 082 shp / 2 299 Kw = 20,00 kts
Range 1 500nm at 12,00 kts (Bunkerage = 46 tons)

Complement:
78 - 102

Cost:
£0,381 million / $1,523 million

Distribution of weights at normal displacement:
Armament: 29 tons, 3,4 %
Armour: 78 tons, 9,1 %
- Belts: 28 tons, 3,3 %
- Torpedo bulkhead: 0 tons, 0,0 %
- Armament: 23 tons, 2,7 %
- Armour Deck: 26 tons, 3,0 %
- Conning Tower: 1 tons, 0,1 %
Machinery: 82 tons, 9,6 %
Hull, fittings & equipment: 574 tons, 67,2 %
Fuel, ammunition & stores: 62 tons, 7,2 %
Miscellaneous weights: 30 tons, 3,5 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
2 621 lbs / 1 189 Kg = 24,5 x 6,0 " / 152 mm shells or 1,3 torpedoes
Stability (Unstable if below 1.00): 1,07
Metacentric height 1,4 ft / 0,4 m
Roll period: 13,9 seconds
Steadiness - As gun platform (Average = 50 %): 92 %
- Recoil effect (Restricted arc if above 1.00): 0,34
Seaboat quality (Average = 1.00): 1,84

Hull form characteristics:
Hull has raised forecastle
and transom stern
Block coefficient: 0,294
Length to Beam Ratio: 6,67 : 1
'Natural speed' for length: 19,95 kts
Power going to wave formation at top speed: 47 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 10,00 degrees
Stern overhang: 3,28 ft / 1,00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 17,81 ft / 5,43 m
- Forecastle (30 %): 16,40 ft / 5,00 m (11,35 ft / 3,46 m aft of break)
- Mid (50 %): 11,35 ft / 3,46 m
- Quarterdeck (15 %): 11,35 ft / 3,46 m
- Stern: 11,35 ft / 3,46 m
- Average freeboard: 13,04 ft / 3,97 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 61,9 %
- Above water (accommodation/working, high = better): 156,7 %
Waterplane Area: 7 029 Square feet or 653 Square metres
Displacement factor (Displacement / loading): 170 %
Structure weight / hull surface area: 60 lbs/sq ft or 295 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0,86
- Longitudinal: 4,09
- Overall: 1,00
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable, can fire her guns in the heaviest weather

Built with surplus arnament from battleships, cruisers and destroyers.

Interesting little creature.

May I assume she´s somewhat bowheavy with that barbet and turret so close to her bow?

Guess that's what those 30 tons miscellaneous weight is for: a ballast tank filled with water to counter ballance that turret.
:-)

"Ship tends to be wet forward"

Her DC magazine and all her AA 40mm is fitted i the stern

Her misc weight is for Deptharges, paravans and possible mineload, her boats are also in that number.

Most of her 2x30ton diesels are in the back as well

I like very much!! Gives me an idea for a new use for my 5.5" guns, allthough I'd like something a tad bigger myself.

I think her size is perfect, small enough to go among the islands, large and steady enough to sail the hig seas.

They are powerfull enough to make an enemy surface raider/AMC think twice before attacking, I gave her and her little littorial friends a site.

Here

I'm not sure how much you think those two boats would be, but being rather 'simple', I think no more than two tons for both of them. That would leave 28 tons for the DCs at the back. I would assume that the diesels would roughly be where the funnel is (or slightly behind it), so that would put the engines in the center. Might be slightly off balance then.

... but looking at it now, isn't a BC of 0.294 a bit low? I had a 'talk' with Ian about the BC (the possibility that a real low BC could work to give a small 10-50 ton MTB/PT boat a reasonable accurate speed with SS), but he told me that that is not a possibility because if you use a BC that is lower than 0.30-0.35 (or so) too many errors will occur in SS to give a proper sim.

I am at work right now, but once I get home, I'll look up the e-mails I got from Ian regarding the low BC.

Well, psilander doesn´t build his ships for WW so I didn´t comment on it but if Ian says a bc below 0,3-0,35 is a no-no some modifications to the design should be considered.

I also like to point out that ships of her kind often were build if not designed on civil yards. They often showed many similarities with civilean/fishing vessels. Hence a hull form similar to a trawler (bc 0,5+) is probably more likely than a very sharp hull.

... it is 0.30.