New kind of cruiser for Peru

[Jefgte]

I agree partialy with you, but Peru want a battle squadron with big guns too.
Fast cruisers are going to be laid down with the new engines techno.


;)

[Jefgte]

7000T cruiser, Peru Escort Cruiser laid down 1918 (Engine 1916)

Displacement:
   7 000 t light; 7 473 t standard; 8 083 t normal; 8 570 t full load

Dimensions: Length overall / water x beam x draught
   393.70 ft / 393.70 ft x 65.62 ft x 21.90 ft (normal load)
   120.00 m / 120.00 m x 20.00 m  x 6.68 m

Armament:
      6 - 10.83" / 275 mm guns (2x3 guns), 661.39lbs / 300.00kg shells, 1918 Model
     Breech loading guns in turrets (on barbettes)
     on centreline, evenly spread
      12 - 4.72" / 120 mm guns in single mounts, 52.72lbs / 23.91kg shells, 1918 Model
     Quick firing guns in casemate mounts
     on side, evenly spread, 4 raised mounts
      4 - 1.57" / 40.0 mm guns (2x2 guns), 1.95lbs / 0.88kg shells, 1918 Model
     Anti-aircraft guns in deck mounts
     on side, evenly spread, all raised mounts
      4 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1918 Model
     Machine guns in deck mounts
     on side, evenly spread, all raised mounts
   Weight of broadside 4 609 lbs / 2 091 kg
   Shells per gun, main battery: 118
   6 - 21.0" / 533 mm above water torpedoes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   5.91" / 150 mm   255.91 ft / 78.00 m   11.15 ft / 3.40 m
   Ends:   1.57" / 40 mm   131.23 ft / 40.00 m   8.01 ft / 2.44 m
     6.56 ft / 2.00 m Unarmoured ends
     Main Belt covers 100 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   6.30" / 160 mm   3.15" / 80 mm      5.51" / 140 mm
   2nd:   0.79" / 20 mm         -               -
   3rd:   0.79" / 20 mm         -               -
   4th:   0.50" / 13 mm         -               -

   - Armour deck: 1.57" / 40 mm, Conning tower: 5.91" / 150 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 4 shafts, 22 000 shp / 16 412 Kw = 22.35 kts
   Range 7 000nm at 12.00 kts
   Bunker at max displacement = 1 097 tons

Complement:
   426 - 554

Cost:
   £1.654 million / $6.614 million

Distribution of weights at normal displacement:
   Armament: 556 tons, 6.9 %
   Armour: 1 813 tons, 22.4 %
      - Belts: 798 tons, 9.9 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 462 tons, 5.7 %
      - Armour Deck: 501 tons, 6.2 %
      - Conning Tower: 51 tons, 0.6 %
   Machinery: 820 tons, 10.1 %
   Hull, fittings & equipment: 3 511 tons, 43.4 %
   Fuel, ammunition & stores: 1 083 tons, 13.4 %
   Miscellaneous weights: 300 tons, 3.7 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     9 445 lbs / 4 284 Kg = 14.9 x 10.8 " / 275 mm shells or 1.7 torpedoes
   Stability (Unstable if below 1.00): 1.05
   Metacentric height 2.9 ft / 0.9 m
   Roll period: 16.2 seconds
   Steadiness   - As gun platform (Average = 50 %): 71 %
         - Recoil effect (Restricted arc if above 1.00): 0.93
   Seaboat quality  (Average = 1.00): 1.31

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.500
   Length to Beam Ratio: 6.00 : 1
   'Natural speed' for length: 19.84 kts
   Power going to wave formation at top speed: 55 %
   Trim (Max stability = 0, Max steadiness = 100): 54
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      23.62 ft / 7.20 m
      - Forecastle (23 %):   19.69 ft / 6.00 m
      - Mid (50 %):      16.40 ft / 5.00 m
      - Quarterdeck (21 %):   16.40 ft / 5.00 m
      - Stern:      16.40 ft / 5.00 m
      - Average freeboard:   17.95 ft / 5.47 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 89.4 %
      - Above water (accommodation/working, high = better): 111.2 %
   Waterplane Area: 17 212 Square feet or 1 599 Square metres
   Displacement factor (Displacement / loading): 99 %
   Structure weight / hull surface area: 133 lbs/sq ft or 652 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.88
      - Longitudinal: 3.08
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is adequate
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

[maddox]

You could shave off a tad of freeboard, what would would give you a tad more tonnage to invest in speed or armor.

[Jefgte]

Exact.

When I decrease freaboard by 0.5m everywhere, Overall is 1.04 & recoil decrease to 0.84

I could extend the belt height to 3.7m & increase the deck armor to 50mm

Stability 1.04
Seaboat quality 1.21


Thanks  ;)

[maddox]

For a Budget BB it's a good job.

One thing that could be changed, is the secundaries.

8 - 4.72" / 120 mm guns in single mounts, 52.72lbs / 23.91kg shells, 1918 Model
     Quick firing guns in casemate mounts
     on side, evenly spread, 4 raised mounts

2 - 4.72" / 120 mm guns in single mounts, 52.72lbs / 23.91kg shells, 1918 Model
     Quick firing guns in casemate mounts
     centerline ends, 2 raised mounts

[Jefgte]

Update



7000T cruiser, Peru Squadron Cruiser laid down 1918 (Engine 1916)

Displacement:
   7 000 t light; 7 464 t standard; 8 074 t normal; 8 561 t full load

Dimensions: Length overall / water x beam x draught
   393.70 ft / 393.70 ft x 65.62 ft x 21.88 ft (normal load)
   120.00 m / 120.00 m x 20.00 m  x 6.67 m

Armament:
      6 - 10.83" / 275 mm guns (2x3 guns), 661.39lbs / 300.00kg shells, 1918 Model
     Breech loading guns in turrets (on barbettes)
     on centreline, evenly spread
      8 - 4.72" / 120 mm guns in single mounts, 52.72lbs / 23.91kg shells, 1918 Model
     Quick firing guns in casemate mounts
     on side, evenly spread, 4 raised mounts
      2 - 4.72" / 120 mm guns in single mounts, 52.72lbs / 23.91kg shells, 1918 Model
     Quick firing guns in casemate mounts
     on centreline ends, evenly spread
      4 - 1.57" / 40.0 mm guns in single mounts, 1.95lbs / 0.88kg shells, 1918 Model
     Anti-aircraft guns in deck mounts
     on side, evenly spread, all raised mounts
      4 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1918 Model
     Machine guns in deck mounts
     on side, evenly spread, all raised mounts
   Weight of broadside 4 504 lbs / 2 043 kg
   Shells per gun, main battery: 118
   6 - 21.0" / 533 mm above water torpedoes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   5.91" / 150 mm   255.91 ft / 78.00 m   11.81 ft / 3.60 m
   Ends:   1.57" / 40 mm   131.23 ft / 40.00 m   8.01 ft / 2.44 m
     6.56 ft / 2.00 m Unarmoured ends
     Main Belt covers 100 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   6.30" / 160 mm   3.94" / 100 mm      5.91" / 150 mm
   2nd:   0.79" / 20 mm         -               -
   3rd:   0.79" / 20 mm         -               -
   4th:   0.50" / 13 mm         -               -

   - Armour deck: 1.77" / 45 mm, Conning tower: 5.91" / 150 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 4 shafts, 22 000 shp / 16 412 Kw = 22.35 kts
   Range 7 000nm at 12.00 kts
   Bunker at max displacement = 1 097 tons

Complement:
   425 - 553

Cost:
   £1.631 million / $6.526 million

Distribution of weights at normal displacement:
   Armament: 543 tons, 6.7 %
   Armour: 1 930 tons, 23.9 %
      - Belts: 841 tons, 10.4 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 474 tons, 5.9 %
      - Armour Deck: 564 tons, 7.0 %
      - Conning Tower: 51 tons, 0.6 %
   Machinery: 820 tons, 10.2 %
   Hull, fittings & equipment: 3 407 tons, 42.2 %
   Fuel, ammunition & stores: 1 074 tons, 13.3 %
   Miscellaneous weights: 300 tons, 3.7 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     9 063 lbs / 4 111 Kg = 14.3 x 10.8 " / 275 mm shells or 1.7 torpedoes
   Stability (Unstable if below 1.00): 1.04
   Metacentric height 2.8 ft / 0.9 m
   Roll period: 16.3 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.83
   Seaboat quality  (Average = 1.00): 1.20

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.500
   Length to Beam Ratio: 6.00 : 1
   'Natural speed' for length: 19.84 kts
   Power going to wave formation at top speed: 55 %
   Trim (Max stability = 0, Max steadiness = 100): 58
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      21.98 ft / 6.70 m
      - Forecastle (23 %):   18.04 ft / 5.50 m
      - Mid (50 %):      14.76 ft / 4.50 m
      - Quarterdeck (21 %):   14.76 ft / 4.50 m
      - Stern:      14.76 ft / 4.50 m
      - Average freeboard:   16.31 ft / 4.97 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 88.3 %
      - Above water (accommodation/working, high = better): 100.8 %
   Waterplane Area: 17 212 Square feet or 1 599 Square metres
   Displacement factor (Displacement / loading): 98 %
   Structure weight / hull surface area: 132 lbs/sq ft or 647 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.89
      - Longitudinal: 2.75
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is adequate
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

[Sachmle]

No offense Jef, but it looks like an underarmored, overranged, highspeed CDS.

[maddox]

It is an underarmored, overranged Coastal defence ship.

So, what would you , Sam, use against it when it's is escorting a convoy? Preferably with a sister or 2 (3 of these are still lighter/cheaper than a new BB/BC)

[Sachmle]

It is an underarmored, overranged Coastal defence ship.

So, what would you , Sam, use against it when it's is escorting a convoy? Preferably with a sister or 2 (3 of these are still lighter/cheaper than a new BB/BC)

Presuming they would be positioned AROUND the convoy, as opposed to GROUPED and only have 5 12cm per side I'd start w/ a mass DD attack w/ some CLs to provide support fire followed up w/ a sub attack once they are even more spread out. Probably 2 CL w/4 DD each. My CLs weigh in ~4000t, so there's 8K, plus 8x500t for TBs, so another 4K. So 12000t in service ships plus 2-3 500t SS, so 1000-1500t...grand total 13000-13500t spent to counter 21000t of warships. Looks good to me.

[Guinness]

I think a ship with 8x9.2" could take one of these. One of those on a bit more displacement could be fast enough for general purpose roles.

Could this ship make 27 knots on less then 12,000 tons I wonder?

My fear with this ship is it will be helplessly slow for even battleline escort in 10 years. In that regard this may be a case of false economy.

[Jefgte]

It was a challenge to study this kind of ship.

I think, one of the most powerfull for 120m lenght.

6x275 on a 7000t hull at 22.3kts with correct protection.

In the battleline, she could engage enemy cruisers inf to 10000t.


;)

[mentat]

It certainly packs a punch - but agree the low speed limit's its capability for the future.

Possible a 6 x 9.2 inch version - to make 25/6 knots with same protection - still a handful for any cruiser - and much more difficult to outmanouevre - you need 3/4 knot advantage to get past/round quickly - and 30 knots is very expensive on fuel ....

Overall - I think would be more effective vs cruisers - and not quite such deadmeat vs Large AC/BC

[The Bushranger]

I'd agree on shrinking the main batteries to the 230-240mm calibre range, and I'd up the armour. Speed isn't really a concern - it's an escort cruiser, and therefore it only needs to be faster than what it's escorting. Merchies won't be making this ship's speed advantage too small for a very long time...

I have to say I blinked twice at the end casemates.

[maddox]

I would make the end casemates superfiring over the main turrets. 
But how they would work, that's another question. Casemates with a traverse more than 180°?

Maybe a giant Scarf ring setup?

[Kaiser Kirk]

I've always figured the forward casements on the US Omaha class CLs could bear both forward (which is how they are usually pictured) and to the side, figured that was an advantage of a corner casement.  Rather expect the end casements on my vessels to bear in such a manner.