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Main Archive => Navalism 3 Armed Forces => Armed Forces => New Ship Designs => Topic started by: ledeper on April 02, 2009, 06:25:29 PM

Title: Esc Corvettes/Asw ship
Post by: ledeper on April 02, 2009, 06:25:29 PM
01-?, Esc Corvettes laid down 1917 (Engine 1916)

Displacement:
   456 t light; 473 t standard; 546 t normal; 604 t full load

Dimensions: Length overall / water x beam x draught
   166,36 ft / 164,04 ft x 29,53 ft x 10,66 ft (normal load)
   50,71 m / 50,00 m x 9,00 m  x 3,25 m

Armament:
      2 - 3,94" / 100 mm guns in single mounts, 30,51lbs / 13,84kg shells, 1917 Model
     Quick firing guns in deck mounts
     on centreline ends, evenly spread
      2 - 1,57" / 40,0 mm guns in single mounts, 1,95lbs / 0,89kg shells, 1917 Model
     Quick firing guns in deck mounts
     on side, all amidships, all raised mounts - superfiring
   Weight of broadside 65 lbs / 29 kg
   Shells per gun, main battery: 150

Machinery:
   Diesel Internal combustion motors,
   Direct drive, 2 shafts, 3.694 shp / 2.755 Kw = 20,00 kts
   Range 4.000nm at 12,00 kts
   Bunker at max displacement = 131 tons

Complement:
   56 - 73

Cost:
   £0,076 million / $0,306 million

Distribution of weights at normal displacement:
   Armament: 8 tons, 1,5 %
   Machinery: 138 tons, 25,2 %
   Hull, fittings & equipment: 201 tons, 36,8 %
   Fuel, ammunition & stores: 90 tons, 16,4 %
   Miscellaneous weights: 110 tons, 20,1 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     566 lbs / 257 Kg = 18,6 x 3,9 " / 100 mm shells or 0,4 torpedoes
   Stability (Unstable if below 1.00): 1,09
   Metacentric height 1,0 ft / 0,3 m
   Roll period: 12,7 seconds
   Steadiness   - As gun platform (Average = 50 %): 56 %
         - Recoil effect (Restricted arc if above 1.00): 0,10
   Seaboat quality  (Average = 1.00): 1,12

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0,370
   Length to Beam Ratio: 5,56 : 1
   'Natural speed' for length: 12,81 kts
   Power going to wave formation at top speed: 66 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   Bow angle (Positive = bow angles forward): 10,00 degrees
   Stern overhang: 0,00 ft / 0,00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      13,12 ft / 4,00 m
      - Forecastle (10 %):   10,60 ft / 3,23 m
      - Mid (50 %):      10,60 ft / 3,23 m
      - Quarterdeck (15 %):   10,60 ft / 3,23 m
      - Stern:      10,60 ft / 3,23 m
      - Average freeboard:   10,70 ft / 3,26 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 115,2 %
      - Above water (accommodation/working, high = better): 106,1 %
   Waterplane Area: 2.944 Square feet or 274 Square metres
   Displacement factor (Displacement / loading): 121 %
   Structure weight / hull surface area: 39 lbs/sq ft or 190 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0,83
      - Longitudinal: 5,77
      - Overall: 1,00
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is adequate

Wt 15 tns
D/C 70 tns(3x70)
Throwers 06 tns(4 throwers+2 ramps)
Reserve 05 tns
Title: Re: Esc Corvettes/Asw ship
Post by: Carthaginian on April 02, 2009, 07:15:42 PM
How'd you get DC Throwers the year that the research became available?
You couldn't even start researching them before this year! ;)

All in all, a nice, cheap ship for ASW duties, though.
EDIT: just noticed that you carry 70 TONS OF DC's! This isn't a ship, it's a floating bomb!
Title: Re: Esc Corvettes/Asw ship
Post by: Logi on April 02, 2009, 07:28:38 PM
Because floating bombs always work better than real ships :D
Title: Re: Esc Corvettes/Asw ship
Post by: Desertfox on April 02, 2009, 08:55:29 PM
What was I saying about getting ahead of ourselves?
Title: Re: Esc Corvettes/Asw ship
Post by: maddox on April 02, 2009, 11:18:16 PM
You're right DF.  I do not know of any ship carrying 70 tons of DC's.
Title: Re: Esc Corvettes/Asw ship
Post by: P3D on April 03, 2009, 01:25:23 AM
The ship is a suicide ASW ship. Get in the vicinity of the sub and KABOOM.
Title: Re: Esc Corvettes/Asw ship
Post by: maddox on April 03, 2009, 01:51:14 AM
A typical  1916 UK depthcharge was a weapon massing about 190 kg. 

Size and shape wag, it's a  drum 65 cm long and 45 cm diameter. Charge 130 kg TNT equivalent.

Let us round it off to 200 kg per weapon.  That means this ship has 350 depth charges on board, and that gives us 45.5 tons of HE, together with pressure sensitive igniters in 1 housing.

But, we'll make it into a cube- more expensive , but easier to store. 
343 charges give a cube of  3.325 meter a side.




From the Navweaps (http://www.navweaps.com/) site.

General Notes (http://www.navweaps.com/Weapons/WAMBR_ASW.htm)
Dropping depth charges off the stern via a rack or track was standard practice for destroyers and destroyer escorts in both World Wars. 
 
Effectiveness

In mid-1916 the D-type depth-charge had been developed, but there were reliability problems with the firing pistols.  Production of these much needed weapons was hampered by technical difficulties, resulting in strict rationing of their use by 1917.  Usually, escorts carried no more than 35 DC, which, given the unreliable detection methods of the time, was considered to be quite inadequate.  The Allies sank about 30 German submarines with DC in World War I; two in 1916, six in 1917 and twenty-two in 1918.