Icebreaker

[ledeper]

Icebear, Esc Icebreaker laid down 1920

Displacement:
   412 t light; 424 t standard; 555 t normal; 659 t full load

Dimensions: Length overall / water x beam x draught
   166,36 ft / 164,04 ft x 42,65 ft x 7,38 ft (normal load)
   50,71 m / 50,00 m x 13,00 m  x 2,25 m

Armament:
      1 - 4,72" / 120 mm guns in single mounts, 52,72lbs / 23,92kg shells, 1920 Model
     Breech loading gun in deck mount
     on centreline forward
   Weight of broadside 53 lbs / 24 kg
   Shells per gun, main battery: 50

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Ends:   3,94" / 100 mm     40,98 ft / 12,49 m   9,84 ft / 3,00 m

Machinery:
   Oil fired boilers, steam turbines,
   Electric motors, 2 shafts, 1.575 shp / 1.175 Kw = 16,00 kts
   Range 8.000nm at 12,00 kts
   Bunker at max displacement = 235 tons

Complement:
   56 - 74

Cost:
   £0,065 million / $0,261 million

Distribution of weights at normal displacement:
   Armament: 7 tons, 1,2 %
   Armour: 59 tons, 10,6 %
      - Belts: 59 tons, 10,6 %
      - Torpedo bulkhead: 0 tons, 0,0 %
      - Armament: 0 tons, 0,0 %
      - Armour Deck: 0 tons, 0,0 %
      - Conning Tower: 0 tons, 0,0 %
   Machinery: 55 tons, 9,9 %
   Hull, fittings & equipment: 241 tons, 43,5 %
   Fuel, ammunition & stores: 143 tons, 25,8 %
   Miscellaneous weights: 50 tons, 9,0 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     2.166 lbs / 982 Kg = 41,1 x 4,7 " / 120 mm shells or 1,4 torpedoes
   Stability (Unstable if below 1.00): 1,48
   Metacentric height 2,7 ft / 0,8 m
   Roll period: 10,8 seconds
   Steadiness   - As gun platform (Average = 50 %): 52 %
         - Recoil effect (Restricted arc if above 1.00): 0,02
   Seaboat quality  (Average = 1.00): 1,03

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0,376
   Length to Beam Ratio: 3,85 : 1
   'Natural speed' for length: 12,81 kts
   Power going to wave formation at top speed: 59 %
   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): 51,8 %
      - Above water (accommodation/working, high = better): 153,6 %
   Waterplane Area: 4.260 Square feet or 396 Square metres
   Displacement factor (Displacement / loading): 204 %
   Structure weight / hull surface area: 43 lbs/sq ft or 212 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0,87
      - Longitudinal: 3,39
      - Overall: 1,00
   Hull space for machinery, storage, compartmentation is excellent
   Room for accommodation and workspaces is excellent

100 mm armor in the bow from 1,5 below MWL to 1,5 meters above

[The Rock Doctor]

I'd probably want a little more seakeeping, but it generally looks fine.

[maddox]

My reply, a lot cheaper due the engines.... A real work engine.

Mange Glace, French Icebreaker laid down 1920 (Engine 1916)

Displacement:
   499 t light; 523 t standard; 647 t normal; 747 t full load

Dimensions: Length overall / water x beam x draught
   213,46 ft / 203,41 ft x 29,53 ft x 6,56 ft (normal load)
   65,06 m / 62,00 m x 9,00 m  x 2,00 m

Armament:
      1 - 5,51" / 140 mm guns in single mounts, 92,59lbs / 42,00kg shells, 1920 Model
     Quick firing gun in deck mount
     on centreline forward
      1 - 2,76" / 70,0 mm guns in single mounts, 11,02lbs / 5,00kg shells, 1920 Model
     Breech loading gun in deck mount
     on centreline forward, 1 raised gun
      2 - 1,46" / 37,0 mm guns in single mounts, 1,55lbs / 0,70kg shells, 1920 Model
     Anti-aircraft guns in deck mounts
     on side, evenly spread
   Weight of broadside 107 lbs / 48 kg
   Shells per gun, main battery: 180

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Ends:   5,00" / 127 mm     30,49 ft / 9,29 m   8,00 ft / 2,44 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0,50" / 13 mm   0,50" / 13 mm            -
   2nd:   0,50" / 13 mm   0,50" / 13 mm            -
   3rd:   0,50" / 13 mm   0,50" / 13 mm            -

Machinery:
   Oil fired boilers, complex reciprocating steam engines,
   Hydraulic drive, 2 shafts, 1.271 ihp / 948 Kw = 15,00 kts
   Range 8.000nm at 10,00 kts
   Bunker at max displacement = 224 tons

Complement:
   63 - 83

Cost:
   £0,090 million / $0,362 million

Distribution of weights at normal displacement:
   Armament: 12 tons, 1,9%
   Armour: 49 tons, 7,6%
      - Belts: 45 tons, 7,0%
      - Torpedo bulkhead: 0 tons, 0,0%
      - Armament: 4 tons, 0,6%
      - Armour Deck: 0 tons, 0,0%
      - Conning Tower: 0 tons, 0,0%
   Machinery: 76 tons, 11,7%
   Hull, fittings & equipment: 237 tons, 36,6%
   Fuel, ammunition & stores: 149 tons, 23,0%
   Miscellaneous weights: 125 tons, 19,3%

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     1.323 lbs / 600 Kg = 15,8 x 5,5 " / 140 mm shells or 0,8 torpedoes
   Stability (Unstable if below 1.00): 1,23
   Metacentric height 1,2 ft / 0,4 m
   Roll period: 11,4 seconds
   Steadiness   - As gun platform (Average = 50 %): 72 %
         - Recoil effect (Restricted arc if above 1.00): 0,14
   Seaboat quality  (Average = 1.00): 1,40

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0,575
   Length to Beam Ratio: 6,89 : 1
   'Natural speed' for length: 14,26 kts
   Power going to wave formation at top speed: 48 %
   Trim (Max stability = 0, Max steadiness = 100): 51
   Bow angle (Positive = bow angles forward): 12,00 degrees
   Stern overhang: 6,56 ft / 2,00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      16,40 ft / 5,00 m
      - Forecastle (15%):   9,84 ft / 3,00 m
      - Mid (65%):      8,96 ft / 2,73 m
      - Quarterdeck (0%):   8,96 ft / 2,73 m
      - Stern:      8,96 ft / 2,73 m
      - Average freeboard:   9,70 ft / 2,96 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 74,5%
      - Above water (accommodation/working, high = better): 119,6%
   Waterplane Area: 4.291 Square feet or 399 Square metres
   Displacement factor (Displacement / loading): 153%
   Structure weight / hull surface area: 38 lbs/sq ft or 185 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0,95
      - Longitudinal: 1,62
      - Overall: 1,00
   Hull space for machinery, storage, compartmentation is excellent
   Room for accommodation and workspaces is adequate
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily




The hydraulic power can be diverted to the excavator that could be bolted to the deck.

[Carthaginian]

Mario's proposal of using the hydraulic engine to power a PTO which could be used for a wide variety of other uses necessary to a ship of this nature makes a lot of sense. The design is surely a contender.

[ledeper]

Icebear, Esc Icebreaker laid down 1920

Displacement:
   508 t light; 524 t standard; 727 t normal; 890 t full load

Dimensions: Length overall / water x beam x draught
   182,76 ft / 180,45 ft x 42,65 ft x 7,38 ft (normal load)
   55,71 m / 55,00 m x 13,00 m  x 2,25 m

Armament:
      1 - 4,72" / 120 mm guns in single mounts, 52,72lbs / 23,91kg shells, 1920 Model
     Breech loading gun in deck mount
     on centreline forward
   Weight of broadside 53 lbs / 24 kg
   Shells per gun, main battery: 50

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Ends:   3,94" / 100 mm     40,98 ft / 12,49 m   9,84 ft / 3,00 m
     16,44 ft / 5,01 m Unarmoured ends

Machinery:
   Oil fired boilers, complex reciprocating steam engines,
   Hydraulic drive, 2 shafts, 1.857 ihp / 1.386 Kw = 16,00 kts
   Range 8.000nm at 12,00 kts
   Bunker at max displacement = 366 tons

Complement:
   69 - 91

Cost:
   £0,091 million / $0,365 million

Distribution of weights at normal displacement:
   Armament: 7 tons, 0,9 %
   Armour: 59 tons, 8,1 %
      - Belts: 59 tons, 8,1 %
      - Torpedo bulkhead: 0 tons, 0,0 %
      - Armament: 0 tons, 0,0 %
      - Armour Deck: 0 tons, 0,0 %
      - Conning Tower: 0 tons, 0,0 %
   Machinery: 109 tons, 15,0 %
   Hull, fittings & equipment: 284 tons, 39,0 %
   Fuel, ammunition & stores: 219 tons, 30,2 %
   Miscellaneous weights: 50 tons, 6,9 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     2.191 lbs / 994 Kg = 41,6 x 4,7 " / 120 mm shells or 1,2 torpedoes
   Stability (Unstable if below 1.00): 1,60
   Metacentric height 3,1 ft / 0,9 m
   Roll period: 10,3 seconds
   Steadiness   - As gun platform (Average = 50 %): 54 %
         - Recoil effect (Restricted arc if above 1.00): 0,02
   Seaboat quality  (Average = 1.00): 1,09

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0,448
   Length to Beam Ratio: 4,23 : 1
   'Natural speed' for length: 13,43 kts
   Power going to wave formation at top speed: 57 %
   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): 63,6 %
      - Above water (accommodation/working, high = better): 143,4 %
   Waterplane Area: 4.901 Square feet or 455 Square metres
   Displacement factor (Displacement / loading): 192 %
   Structure weight / hull surface area: 44 lbs/sq ft or 214 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0,90
      - Longitudinal: 2,67
      - Overall: 1,00
   Hull space for machinery, storage, compartmentation is excellent
   Room for accommodation and workspaces is excellent

100 mm armor in the bow from 1,5 below MWL to 1,5 meters above
The gun is for shooting holes in the ice

[Borys]

Ahoj!
I believe that the gun would not be very effective.
Borys

[mentat]

perhaps a mortar instead?

[Nobody]

Yesterday I found an interesting article describing the differences between a normal ship and an icebreaker capable of handling at least 50 to 100 cm of ice. The typical icebreaker hull is described has having twice as many frames/ribs as normal ship and high tensile steel propellers (instead of brass). It also has thicker hull plating form 2 meters below to 0.5 meters above the waterline. The plating is roughly 50% thicker on sides and twice as thick in the specially shaped bow area - much thinner than I thought because the normal hull plating seems to be only about 10 to 13 mm (.4" to .5"), and even less above the "belt" (6 mm/.236").

[Jefgte]

The bow form is made to climb the ice.




Jef

[mentat]

great pic - but I don't recognise - is it composite pic?

Anyone else have good info. on Icebreakers - they are so Macho  ;D

[Jefgte]

Thats 1917 Black Sea Battleship - the Kostenko Design

http://www.gwpda.org/naval/irn16bb.htm


;)

[Sachmle]

great pic - but I don't recognise - is it composite pic?

Anyone else have good info. on Icebreakers - they are so Macho  ;D

Thats 1917 Black Sea Battleship - the Kostenko Design

http://www.gwpda.org/naval/irn16bb.htm


;)

Not exactly Jef, the little mark/note/symbol/whatever in the bottom right corner identifies it as one of Alt_Naval's altered pictures.

[Borys]

Ahoj!
Hmmm - maybe I will use that photo as base for my 3x4x15" ship ...
Bprys

[Sachmle]

Ahoj!
Hmmm - maybe I will use that photo as base for my 3x4x15" ship ...
Bprys

But the pic is a 3x3x16" ship.

[maddox]

I can see at least 3 turrets, were the A turret is a quad in that Bubnov ship .