WesWorld

D Class, Iberia Submarine (Ocean) laid down 1935

Displacement:
1,446 t light; 1,482 t standard; 1,620 t normal; 1,730 t full load

Dimensions: Length overall / water x beam x draught
199.15 ft / 196.85 ft x 18.04 ft (Bulges 21.33 ft) x 13.94 ft (normal load)
60.70 m / 60.00 m x 5.50 m (Bulges 6.50 m) x 4.25 m

Armament:
2 - 3.94" / 100 mm guns in single mounts, 30.51lbs / 13.84kg shells, 1935 Model
Breech loading guns in deck mounts
on centreline, all amidships
2 - 0.98" / 25.0 mm guns (1x2 guns), 0.48lbs / 0.22kg shells, 1935 Model
Anti-aircraft guns in deck mount
on centreline amidships, all raised guns - superfiring
2 - 0.53" / 13.5 mm guns in single mounts, 0.08lbs / 0.03kg shells, 1935 Model
Machine guns in deck mounts
on side, all amidships, all raised mounts - superfiring
Weight of broadside 62 lbs / 28 kg
Shells per gun, main battery: 100
2 - 20.9" / 530 mm above water torpedoes, 6 - 20.9" / 530 mm submerged torpedo tubes

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

- Conning tower: 0.59" / 15 mm

Machinery:
Diesel Internal combustion generators plus batteries,
Electric motors, 2 shafts, 5,092 shp / 3,798 Kw = 18.00 kts
Range 8,000nm at 10.00 kts
Bunker at max displacement = 248 tons

Complement:
63

Cost:
£0.394 million / $1.576 million

Distribution of weights at normal displacement:
Armament: 8 tons, 0.5 %
Armour: 5 tons, 0.3 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 4 tons, 0.2 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 2 tons, 0.1 %
Machinery: 145 tons, 8.9 %
Hull, fittings & equipment: 989 tons, 61.0 %
Fuel, ammunition & stores: 174 tons, 10.7 %
Miscellaneous weights: 300 tons, 18.5 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
498 lbs / 226 Kg = 16.3 x 3.9 " / 100 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.02
Metacentric height 0.4 ft / 0.1 m
Roll period: 14.2 seconds
Steadiness - As gun platform (Average = 50 %): 5 %
- Recoil effect (Restricted arc if above 1.00): 0.02
Seaboat quality (Average = 1.00): 0.01

Hull form characteristics:
Hull has raised forecastle
Block coefficient: 0.969
Length to Beam Ratio: 9.23 : 1
'Natural speed' for length: 14.03 kts
Power going to wave formation at top speed: 67 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 35.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 3.28 ft / 1.00 m
- Forecastle (15 %): 3.28 ft / 1.00 m (1.64 ft / 0.50 m aft of break)
- Mid (60 %): 1.64 ft / 0.50 m
- Quarterdeck (15 %): 0.00 ft / 0.00 m
- Stern: 0.00 ft / 0.00 m
- Average freeboard: 1.44 ft / 0.44 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 133.4 %
- Above water (accommodation/working, high = better): 4.5 %
Waterplane Area: 3,546 Square feet or 329 Square metres
Displacement factor (Displacement / loading): 247 %
Structure weight / hull surface area: 172 lbs/sq ft or 842 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 5.44
- Longitudinal: 3.14
- Overall: 3.60


Diving depth = 360'
Emergency dive = 576'
Crush depth = 900'

2 bow tubes are mounted in the upper works above the pressure vessel, and are not reloadable underway.

A gunshield on a sub cannon? Going to create a lot of drag, isn't it?

My only nitpick is the two tubes in the upper works. Is it really worth it to have 2 additional torpedo tubes if they only fire once?

As for the gunshiled, why not? If its a flat armour plate then yeah drag will be an issue, but if its a streamlined guard plate drag shouldn't be an issue.

Think of the gunshield on the British T-class, thats what I'm going for, thats why I added "Other Gunhouse" armour, to simulate the sides.

Likewise the torpedoes.

Guess I have a soft spot for the T class!!

Personally I'd just up the reloads for torpedos by two and remove the upperworks tubes. I would think having two tubes outside the pressure hull would make them vulnerable to shellfire from subhunters and destroyers.....wait a minute you never heard that from me!

*Atlantean admirals circle recognition charts of the D class sub around the area of the upperworks torpedo's. "Aim here!"*

Wasn't there some French submarine that had a huge number of deck mounted tubes? While they are one shots, such a ship would be interesting for something like, say harbor defense or invasion breakup duty?

The upper tubes would always be fired first, so no longer a target!

The Netherlands historically had casement tubes holding a larger ~21" torpedo than those ~18" inside the pressure hull.

This means that if you are aiming for merchants, you can use the 18", while against a warships with TD, you can fire the casement tubes in the hopes of breaching. I suppose the combo would also allow you to have a heavier slavo weight if you figured one chance.

Obviously, simply having all 21" or 24" inside the sub would be great, but then you chew up a great deal more internal space and can carry fewer reloads for the same size sub.

As I recall, the Dutch also had both streamlined gun shields, and disappearing gun mounts to improve underwater performance and reduce turbulence.

Quoted

Originally posted by Ithekro
Wasn't there some French submarine that had a huge number of deck mounted tubes? While they are one shots, such a ship would be interesting for something like, say harbor defense or invasion breakup duty?

Many of Surcouf's tubes were external turrets.

Quite a few of the British subs had external tubes in the saddle tanks that couldn't be reloaded underwater. I don't remember them being particularly vulnerable as they're not very big.

Quoted

Originally posted by ShinRa_Inc

Many of Surcouf's tubes were external turrets.

I am not sure Surcouf is an example one wants to follow

Quoted

Originally posted by LordArpad

Quoted

Originally posted by ShinRa_Inc

Many of Surcouf's tubes were external turrets.

I am not sure Surcouf is an example one wants to follow

I'm not, and have no intention of.........

I'm going to build this!!!!



.... well, a guy can dream....can't he?

Pretty cool! o.O

Anyone want to try simming it??????

Without the Nukes, of course!!

Heh heh, heh heh. You too huh? I had a Sub carrier design I wanted to do some years ago. I think around the time the Navy was looking into alternatives for the CVN-21 type (now the Ford-class). Use to discuss this with the Exploer Post and later with a co-worker who also had an idea on the matter.

Good luck trying to get those elevators watertight! You'd likely need a recessed ramp in the flight deck that leads to a water tight door.

I proposed an airlock like setup. But then I was thinking of using an streamlined extendable elevator to launch VSTOL aircract from below the surface (periscope depth). Not a lot of planes due to the nature of the vessel, but enough that come out of nowhere to make it useful in a LPH type of way.