Not too big gun?

[Borys]

SMS Erdely, Habsburg Awizo laid down 1905 (Engine 1909)
Barbette ship

Displacement:
   2 665 t light; 2 751 t standard; 3 055 t normal; 3 298 t full load

Dimensions: Length overall / water x beam x draught
   330,35 ft / 330,00 ft x 40,00 ft x 12,00 ft (normal load)
   100,69 m / 100,58 m x 12,19 m  x 3,66 m

Armament:
      1 - 7,50" / 191 mm guns in single mounts, 200,00lbs / 90,72kg shells, 1905 Model
     Breech loading gun in open barbette
     on centreline aft
      4 - 4,00" / 102 mm guns in single mounts, 35,00lbs / 15,88kg shells, 1905 Model
     Breech loading guns in deck mounts
     on centreline, all forward
      4 - 0,43" / 11,0 mm guns in single mounts, 0,04lbs / 0,02kg shells, 1905 Model
     Breech loading guns in deck mounts
     on side, evenly spread
   Weight of broadside 340 lbs / 154 kg
   Shells per gun, main battery: 120
   2 - 14,0" / 355,6 mm above water torpedoes

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   1,00" / 25 mm         -               -

Machinery:
   Coal fired boilers, complex reciprocating steam engines,
speed estimated at 18-20 knots, range unknown

Complement:
   205 - 267

Cost:
   £0,319 million / $1,275 million

Distribution of weights at normal displacement:
   Armament: 42 tons, 1,4%
   Armour: 5 tons, 0,2%
      - Belts: 0 tons, 0,0%
      - Torpedo bulkhead: 0 tons, 0,0%
      - Armament: 5 tons, 0,2%
      - Armour Deck: 0 tons, 0,0%
      - Conning Tower: 0 tons, 0,0%
   Machinery: 1 357 tons, 44,4%
   Hull, fittings & equipment: 1 111 tons, 36,4%
   Fuel, ammunition & stores: 390 tons, 12,8%
   Miscellaneous weights: 150 tons, 4,9%

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     1 499 lbs / 680 Kg = 7,1 x 7,5 " / 191 mm shells or 0,5 torpedoes
   Stability (Unstable if below 1.00): 1,32
   Metacentric height 2,1 ft / 0,6 m
   Roll period: 11,7 seconds
   Steadiness   - As gun platform (Average = 50 %): 71 %
         - Recoil effect (Restricted arc if above 1.00): 0,16
   Seaboat quality  (Average = 1.00): 1,22

Hull form characteristics:
   Hull has raised forecastle
   Block coefficient: 0,675
   Length to Beam Ratio: 8,25 : 1
   'Natural speed' for length: 18,17 kts
   Power going to wave formation at top speed: 62 %
   Trim (Max stability = 0, Max steadiness = 100): 58
   Bow angle (Positive = bow angles forward): 1,00 degrees
   Stern overhang: -5,00 ft / -1,52 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      20,12 ft / 6,13 m
      - Forecastle (43%):   19,12 ft / 5,83 m (12,12 ft / 3,69 m aft of break)
      - Mid (50%):      12,12 ft / 3,69 m
      - Quarterdeck (15%):   12,12 ft / 3,69 m
      - Stern:      12,12 ft / 3,69 m
      - Average freeboard:   15,30 ft / 4,66 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 159,4%
      - Above water (accommodation/working, high = better): 111,1%
   Waterplane Area: 10 345 Square feet or 961 Square metres
   Displacement factor (Displacement / loading): 93%
   Structure weight / hull surface area: 66 lbs/sq ft or 323 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 1,11
      - Longitudinal: 2,45
      - Overall: 1,20
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is adequate
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

Warning: Mount cannot have above deck armour - Main battery

[The Rock Doctor]

I'm not sure what you're asking there...

This looks more like a monitor than a gunship/sloop type vessel. 

[Borys]

Ahoj!
I'm asking as I'm worried if such small hull could support such a BFG.
Originally this design was to carry a 6 inch gun, but having tonnage to spare I got carried away and put a 7'5 incher on her.
A bit of an overkill when used against mudhuts, I (now) think ....
The bathtub shape will come in handy in Persian Gulf shoals, Pacific atols, off East Africa. Not sure if I need such small draught off Brasil. But it will make friendly visits at Manaus easier.

Took your advice on the foreign relations.

Borys

[The Rock Doctor]

Structurally, I think the hull is up to the task; the question is whether there's enough vertical height for the barbette to fit into the hull.

Check out the river monitor I posted in the 1905 GC ships thread - I put a 7.64" gun into a ~900 t hull.

I think the Brits built smaller monitors with similar or larger guns for WW1...

[Borys]

Ahoj!
One thing is SS allowing you to do something, another thing is the thing being plausible or useful.

Hmm - gun lenght is about 8 metres, if I trunnion it one third  down the barrel, I have the breech sticking out some 2,7 metres. On a 12 metre hull that's just over 3 metres, 10 feet, from the closed breech to the side railing. Seems like enough space for the crew to work on ...

Borys

[The Rock Doctor]

Sure, but we're not talking about a 15" gun.  I think a single 7.5" is quite reasonable on this hull size.  As I said, the Brits put similar guns on much smaller hulls, so I wouldn't worry about it.

[P3D]

USA did put 8" guns on its old cruisers regularly.

[Borys]

Ahoj!

We are talking about a 3000 ship here ....

Borys

[The Rock Doctor]

A Gazelle class cruiser has similar displacement and carried 10 x 105 mm guns.  I think you can reasonaly trade six of those for a single 190 mm gun...?

[P3D]

Those old US cruisers had 2x8" on 4500t full load.

Orange have cruisers - admittedly inspired by them with 2x8" on 3000t.
Baltimore had 4x8" on 5500t full load.

http://hazegray.org/navhist/cruisers/cruiser1.htm

PS. I love this software. This automatically converts URLs, no need for [url] tags.

[swamphen]

There was a @ design I saw once for an Austrian cruiser, circa 1905 IIRC, that had 2x2 210mm on a 4500-ton hull.

[Borys]

Ahoj!
It is possible. But I doubt the utility of that vessel. Also, I do not have the luxury(?) of building for the Adriatic.
The ships of the KuKK are a Hochseeflotte, not a Braunwasserflotte like it used to be.

Borys