WesWorld

I wonder if you have a drawing illustrating the placement of the main and secondary guns, and the torpedo tubes, on such a small deck?

I find it difficult to accept that such a small hull could carry two twin 105mm mounts on such a small beam. I realize that Springsharp might allow it; are there historical vessels of comparable size with such heavy armament?

To many guns, major NEDS case here.

Quoted

Originally posted by snip
To many guns, major NEDS case here.

NEDS? Could you enlighten the uninformed here?

Not Enough Deck Space

In the spirit of bigger 200t, this class is not exactly what I want.
(Yes but SS allow this armament with 0.56 recoil.)
Deck arrangement is inspired from "la Jeune école" :
=> Hull with very light superstructures.

For Defender, I prefer 2x1x105 & increase misc weight to have better deck space & more diff material possibility.
always inf to 300t.

Jef

Quoted

Originally posted by snip
Not Enough Deck Space

Thank you for clarifying.

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

Displacement:
290 t light; 310 t standard; 355 t normal; 391 t full load

Dimensions: Length overall / water x beam x draught
189.34 ft / 183.73 ft x 22.97 ft x 7.00 ft (normal load)
57.71 m / 56.00 m x 7.00 m x 2.14 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: 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, 4 540 shp / 3 387 Kw = 24.03 kts
Range 3 000nm at 15.00 kts
Bunker at max displacement = 81 tons

Complement:
40 - 53

Cost:
£0.225 million / $0.899 million

Distribution of weights at normal displacement:
Armament: 9 tons, 2.6 %
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: 110 tons, 31.1 %
Hull, fittings & equipment: 101 tons, 28.6 %
Fuel, ammunition & stores: 65 tons, 18.4 %
Miscellaneous weights: 65 tons, 18.3 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
159 lbs / 72 Kg = 4.5 x 4.1 " / 105 mm shells or 0.2 torpedoes
Stability (Unstable if below 1.00): 1.02
Metacentric height 0.6 ft / 0.2 m
Roll period: 12.7 seconds
Steadiness - As gun platform (Average = 50 %): 71 %
- Recoil effect (Restricted arc if above 1.00): 0.29
Seaboat quality (Average = 1.00): 1.01

Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.420
Length to Beam Ratio: 8.00 : 1
'Natural speed' for length: 15.94 kts
Power going to wave formation at top speed: 69 %
Trim (Max stability = 0, Max steadiness = 100): 70
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: 15.42 ft / 4.70 m
- Forecastle (20 %): 12.14 ft / 3.70 m
- Mid (50 %): 8.53 ft / 2.60 m
- Quarterdeck (18 %): 8.20 ft / 2.50 m
- Stern: 8.20 ft / 2.50 m
- Average freeboard: 9.94 ft / 3.03 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 142.8 %
- Above water (accommodation/working, high = better): 78.9 %
Waterplane Area: 2 731 Square feet or 254 Square metres
Displacement factor (Displacement / loading): 95 %
Structure weight / hull surface area: 20 lbs/sq ft or 97 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 2.86
- Overall: 0.59
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

20t: Boom for minesweeping / trawling / salvage
10t ASDIC + 20 tons for 60DC
10t Radar
5t reserve

I still think that 105's are to large for this hull, going to something in the ~75mm range would be better IMO.

The above drawing shows a 200ts design used by the RSAN. It is armed with 2x 88mm, 2x 40mm and two 2cm cannons, no torps.

I think it might be possible to fit two 105mm guns, judging from the drawing alone, but the overall number of weapons might be an issue.

The RSAN also fields a 200ts with two 15cm guns, but it is a river monitor with little value anywhere else except on the calm waters of a river - and again the overall number of guns and mounts is much smaller.

Great Thanks to HoOmAn to give some possibilities.



Here is Chasser class, 200t - 50m - with 2TTx450

200t-Chasser Class, Peru MineSweeper-SubChasser-Escort laid down 1944

Displacement:
200 t light; 211 t standard; 225 t normal; 236 t full load

Dimensions: Length overall / water x beam x draught
169.54 ft / 164.04 ft x 22.31 ft x 5.07 ft (normal load)
51.67 m / 50.00 m x 6.80 m x 1.55 m

Armament:
1 - 4.13" / 105 mm guns in single mounts, 35.32lbs / 16.02kg shells, 1944 Model
Quick firing gun in deck mount
on centreline forward
4 - 0.98" / 25.0 mm guns (2x2 guns), 0.48lbs / 0.22kg shells, 1944 Model
Machine guns in deck mounts
on side, evenly spread
Weight of broadside 37 lbs / 17 kg
Shells per gun, main battery: 300
2 - 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, 1 shaft, 1 660 shp / 1 238 Kw = 19.84 kts
Range 2 000nm at 12.00 kts
Bunker at max displacement = 25 tons

Complement:
28 - 37

Cost:
£0.113 million / $0.453 million

Distribution of weights at normal displacement:
Armament: 5 tons, 2.1 %
Armour: 2 tons, 0.7 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 2 tons, 0.7 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 42 tons, 18.9 %
Hull, fittings & equipment: 121 tons, 53.9 %
Fuel, ammunition & stores: 25 tons, 11.1 %
Miscellaneous weights: 30 tons, 13.3 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
457 lbs / 207 Kg = 12.9 x 4.1 " / 105 mm shells or 0.4 torpedoes
Stability (Unstable if below 1.00): 1.03
Metacentric height 0.6 ft / 0.2 m
Roll period: 12.5 seconds
Steadiness - As gun platform (Average = 50 %): 69 %
- Recoil effect (Restricted arc if above 1.00): 0.18
Seaboat quality (Average = 1.00): 1.27

Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.424
Length to Beam Ratio: 7.35 : 1
'Natural speed' for length: 15.17 kts
Power going to wave formation at top speed: 63 %
Trim (Max stability = 0, Max steadiness = 100): 54
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: 15.09 ft / 4.60 m
- Forecastle (20 %): 11.81 ft / 3.60 m
- Mid (50 %): 8.53 ft / 2.60 m
- Quarterdeck (18 %): 7.87 ft / 2.40 m
- Stern: 7.87 ft / 2.40 m
- Average freeboard: 9.72 ft / 2.96 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 93.7 %
- Above water (accommodation/working, high = better): 108.3 %
Waterplane Area: 2 376 Square feet or 221 Square metres
Displacement factor (Displacement / loading): 146 %
Structure weight / hull surface area: 29 lbs/sq ft or 139 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.83
- Longitudinal: 5.26
- Overall: 1.00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is adequate
Good seaboat, rides out heavy weather easily

10 tons Asdic +
20 tons Material for Mines chasser or 20 tons for 60 DC

Quoted

Originally posted by snip
I still think that 105's are to large for this hull, going to something in the ~75mm range would be better IMO.

While I agree with you in principle, I can accept two single 105mm on a vessel this size far more easily than I can accept one with two twin 105mm guns. Personally I would confine myself to a single large gun forward, a mid-range LAA gun on the centerline aft and the light AA on the beam, but that is a personal preference thing.

The 290-ton design presented here is not necessarily the best design, but it is a minimally acceptable one IMHO.

Quoted

Originally posted by Jefgte
Great Thanks to HoOmAn to give some possibilities.

Welcome, but I think you did not really capture my point. While I agree that single guns of a calibre up to 105mm might be okay, torpedos are a different thing.

The usual torpedo and torpedo tube is about 7m long, best guess. You also need some room to turn the thing. Now consider how much of your available deck space is consumed...

So either your design features fixed tubes (but you did not say so and I cannot see that on a ship the category you propose) or you a really in deep trouble regarding deck space given all the other stuff you need there - including free space to actually move the crew and maneouvre the vessel.

Any chance you can provide us a drawing showing the intended deck layout?

I can go with a single 105, seeing as she carries no other guns above MGs (abit large ones)

Quoted

The usual torpedo and torpedo tube is about 7m long, best guess. You also need some room to turn the thing. Now consider how much of your available deck space is consumed...

Rapid estimation give:
Forecastle = 10m
105mm Gun plateform = 4m
Bridge = 4m
Stack = 2m (with 25mm AA platform side)
Torpedoe = 9m
25mm Gun Plateform =3m
Lifeboat = 7m (DC below)
Aft deck = 8m (with DC)

Total 48m for a 50m hull.
2m dispo for adjustments.

Have a look on the CTBM200 developed for Navalism-Peru.
This is nearly the same family of 200t ship

http://www.navalism.org/index.php/topic,4644.0.html

No problemo for deck place.

Jef

My question would be why a 19 knot sub-chaser/ minesweeper needs torpedo tubes at all?

Surely both of the those roles require lots of quarterdeck space. Your TBM-200 seems very cramped aft, not the sort of place you want to be reloading depth-charges or operating sweeps etc.

Quoted

My question would be why a 19 knot sub-chaser/ minesweeper needs torpedo tubes at all?

200t-Chasser Class, Peru MineSweeper-SubChasser-Escort laid down 1944

This is a multirole ship
Minesweeper
Sub Chasser
Escort & Harbour protection

Jef

I think this pretty adequately shows the dangers of trying to make something "too multipurpose". It tries to be all things to all men, and becomes none of them.

...

When you have a low construction potential, versatility is the way to increase defensive or offensive power.

Quoted

I think this pretty adequately shows the dangers of trying to make something "too multipurpose". It tries to be all things to all men, and becomes none of them.

Dangers !!!

Where are Dangers ?