WesWorld

CM28, Filipino Minelayer laid down 1928

Displacement:
4,573 t light; 4,729 t standard; 5,501 t normal; 6,118 t full load

Dimensions: Length overall / water x beam x draught
488.24 ft / 472.50 ft x 51.00 ft x 17.00 ft (normal load)
148.81 m / 144.02 m x 15.54 m x 5.18 m

Armament:
4 - 6.10" / 155 mm guns in single mounts, 120.00lbs / 54.43kg shells, 1928 Model
Quick firing guns in deck mounts with hoists
on centreline ends, evenly spread, 2 raised mounts - superfiring
8 - 2.24" / 57.0 mm guns in single mounts, 6.00lbs / 2.72kg shells, 1928 Model
Dual purpose guns in deck mounts with hoists
on side, evenly spread, 4 raised mounts
6 - 0.98" / 25.0 mm guns (2x3 guns), 0.57lbs / 0.26kg shells, 1928 Model
Anti-aircraft guns in deck mounts
on side, all amidships
8 - 0.54" / 13.7 mm guns (4x2 guns), 0.11lbs / 0.05kg shells, 1928 Model
Machine guns in deck mounts
on side ends, evenly spread, all raised mounts

Weight of broadside 532 lbs / 241 kg
Shells per gun, main battery: 150

2 - 24.0" / 610 mm submerged torpedo tubes

Mines @ 1,000lbs each: 325
or Depth Charges @ 550lbs each: 600

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 3.15" / 80 mm 328.08 ft / 100.00 m 9.84 ft / 3.00 m
Ends: Unarmoured
Main Belt covers 107 % of normal length
Main belt does not fully cover magazines and engineering spaces

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.97" / 50 mm 1.18" / 30 mm 1.97" / 50 mm
2nd: 0.98" / 25 mm - 0.79" / 20 mm
3rd: 0.59" / 15 mm - -

- Armour deck: 1.18" / 30 mm, Conning tower: 3.15" / 80 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 60,126 shp / 44,854 Kw = 31.50 kts
Range 8,500nm at 15.00 kts (Bunkerage = 1,389 tons)

Complement:
319 - 415

Cost:
£1.813 million / $7.254 million

Distribution of weights at normal displacement:
Armament: 63 tons, 1.1 %
Armour: 825 tons, 15.0 %
- Belts: 421 tons, 7.7 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 41 tons, 0.7 %
- Armour Deck: 342 tons, 6.2 %
- Conning Tower: 21 tons, 0.4 %
Machinery: 1,872 tons, 34.0 %
Hull, fittings & equipment: 1,613 tons, 29.3 %
Fuel, ammunition & stores: 928 tons, 16.9 %
Miscellaneous weights: 200 tons, 3.6 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
3,460 lbs / 1,569 Kg = 30.4 x 6.1 " / 155 mm shells or 0.8 torpedoes
Stability (Unstable if below 1.00): 1.21
Metacentric height 2.6 ft / 0.8 m
Roll period: 13.3 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.29
Seaboat quality (Average = 1.00): 1.08

Hull form characteristics:
Hull has low quarterdeck
Block coefficient: 0.470
Length to Beam Ratio: 9.26 : 1
'Natural speed' for length: 21.74 kts
Power going to wave formation at top speed: 61 %
Trim (Max stability = 0, Max steadiness = 100): 65
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 7.00 ft / 2.13 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 24.00 ft / 7.32 m
- Forecastle (20 %): 19.00 ft / 5.79 m
- Mid (50 %): 19.00 ft / 5.79 m
- Quarterdeck (15 %): 10.00 ft / 3.05 m (18.00 ft / 5.49 m before break)
- Stern: 10.00 ft / 3.05 m
- Average freeboard: 17.88 ft / 5.45 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 128.4 %
- Above water (accommodation/working, high = better): 174.8 %
Waterplane Area: 15,632 Square feet or 1,452 Square metres
Displacement factor (Displacement / loading): 104 %
Structure weight / hull surface area: 62 lbs/sq ft or 302 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.70
- Longitudinal: 1.35
- Overall: 0.75
Caution: Hull subject to strain in open-sea
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform

Is there a reason her belt is too short?

In general she looks much like a "copy" or better call it "WesWorld version" of French mine cruiser PLUTON. Her hull dimensions and displacement is identical. However, using the 0,75 hs we allow for small units your design is superior to her real world sister by far in every aspect.

I just don´t understand what her TTs are good for and - to some degree - I wonder why the Filipinos build such ship.

Regards,

HoOmAn

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In general she looks much like a "copy" or better call it "WesWorld version" of French mine cruiser PLUTON.

How did you ever guess? ;-)

Quoted

Is there a reason her belt is too short?

It is intended to cover the machinery and the mine storage only. (It's also the maximum I could get at 80mm thickness.)

Quoted

I just don´t understand what her TTs are good for

Well, it's quite possible that her "official stats" will obmit that little item, and the first faster vessel to give chase will receve an exceedingly nasty Long Lance surprise. ^_^

Quoted

to some degree - I wonder why the Filipinos build such ship.

After having concentrated on light BCs and the 1927 CV, I'm turning my attention to defensive forces.

I have the following plan for a mine warfare force:

-This ship as Flag, Mine Forces.

-Two Mine Warfare Squadrons, each with a version of my previously posted CM29 as flag, and four Rabihorcado-class DDs converted to destroyer-minesweepers.

In addition, I'm musing on the possiblity of later on building a "WW-version" of the OTL Japanese Itukusima, to act as "leader" for my currently-exsisting light mine forces.

Shes far too slow for a minelayer. With a ship that big I'm sure you could get up to 36knts with ease. Why bother giving her armour? I can't really see the point as shes not going to be engaged in action.

Quoted

Well, it's quite possible that her "official stats" will obmit that little item, and the first faster vessel to give chase will receve an exceedingly nasty Long Lance surprise. ^_^

CM28 vs. one of my Commondante Class esploratori (to be built in 1927, details soon). If a stern chase starts as you think, CM28 will soon be run down. However first she'll be blown sky-high as multiple shells ignite the mines that she is carrying. How do you shoot torpedoes dead astern when you are doing full speed? Isn't the stern going to be already cluttered from mine storage?

I don't think submerged torpedoes on a +30knt ships is a good idea. They can't be launched at over 20knots so if you are being chased then you'll have to slow down even if they point aft.

Cheers,

I think alt_naval has a point here.

Regarding speed I´d like to point out that I disagree with RA. She´s not too slow, she´s probably too fast (machinery consuming too much space and weight).

For defensive mine laying speed doesn´t matter and offensive mine laying doesn´t happen in broad daylight. Further more history tells us that there were several successful mine ops in WW1 and WW2 and most of them were carried out by vessels MUCH slower than 31,5kn. An exception where the German DDs at the beginning of WW2 of course which run some very risky mine missions.

I also question the value of armor on such a vessel. If you really need a fast mine layer for offensive mine laying you´d better skip her armor and add another knot od speed or two. Think of the british MANXMAN-type MLs.

The torpedo tubes are actually broadside. I was thinking that turning to engage (and bringing all four guns to bear) would allow her to slow down enough...

Nevertheless, good points, and I'll try redoing her w/out the armour, and with the fish either removed or above-water.

The speed is due to the fact that this ship will be classified as a 'Cruiser Minelayer', and will have a secondary role with the fleet. In order to keep up with my Cruiser Groups, she has to have a minimum speed of 31.5 knots...

Decided against upping the speed, instead used the gains from removal of the armour torwards increased range and stowage. Also modified the secondary/AA armament. Now the hull strength is at 1.00 as well.

Forgot to mention that this ship will carry an a/c and catapult...

Also, the 155mm guns will be lined down to 6", for Treaty purposes.


PRS Dalupiri, Filipino minelaying cruiser laid down 1928

Displacement:
4,444 t light; 4,601 t standard; 5,504 t normal; 6,227 t full load

Dimensions: Length overall / water x beam x draught
491.24 ft / 472.44 ft x 50.85 ft x 17.06 ft (normal load)
149.73 m / 144.00 m x 15.50 m x 5.20 m

Armament:
4 - 6.10" / 155 mm guns in single mounts, 120.00lbs / 54.43kg shells, 1928 Model
Quick firing guns in deck mounts with hoists
on centreline ends, evenly spread, 2 raised mounts - superfiring
4 - 2.95" / 75.0 mm guns in single mounts, 13.00lbs / 5.90kg shells, 1928 Model
Dual purpose guns in deck mounts with hoists
on side ends, evenly spread, 2 raised mounts
2 - 1.57" / 40.0 mm guns in single mounts, 2.00lbs / 0.91kg shells, 1928 Model
Quick firing guns in deck mounts
on side, all aft, all raised mounts
6 - 0.98" / 25.0 mm guns (2x3 guns), 0.57lbs / 0.26kg shells, 1928 Model
Anti-aircraft guns in deck mounts
on side, all amidships
8 - 0.54" / 13.7 mm guns (4x2 guns), 0.11lbs / 0.05kg shells, 1928 Model
Machine guns in deck mounts
on side ends, evenly spread, all raised mounts

Weight of broadside 540 lbs / 245 kg
Shells per gun, main battery: 150

2 - 24.0" / 610 mm above water torpedoes

Mines @ 1,000lbs each: 425
or Depth Charges @ 550lbs each: 800

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.97" / 50 mm 1.18" / 30 mm 1.97" / 50 mm
2nd: 0.98" / 25 mm 0.59" / 15 mm 0.79" / 20 mm
3rd: 0.79" / 20 mm - -
4th: 0.59" / 15 mm - -

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 60,122 shp / 44,851 Kw = 31.50 kts
Range 10,000nm at 15.00 kts (Bunkerage = 1,626 tons)

Complement:
319 - 415

Cost:
£1.800 million / $7.201 million

Distribution of weights at normal displacement:
Armament: 64 tons, 1.2 %
Armour: 39 tons, 0.7 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 39 tons, 0.7 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 1,872 tons, 34.0 %
Hull, fittings & equipment: 2,168 tons, 39.4 %
Fuel, ammunition & stores: 1,060 tons, 19.3 %
Miscellaneous weights: 300 tons, 5.5 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
4,801 lbs / 2,178 Kg = 42.3 x 6.1 " / 155 mm shells or 0.9 torpedoes
Stability (Unstable if below 1.00): 1.17
Metacentric height 2.4 ft / 0.7 m
Roll period: 13.7 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.31
Seaboat quality (Average = 1.00): 1.07

Hull form characteristics:
Hull has low quarterdeck
Block coefficient: 0.470
Length to Beam Ratio: 9.29 : 1
'Natural speed' for length: 21.74 kts
Power going to wave formation at top speed: 61 %
Trim (Max stability = 0, Max steadiness = 100): 65
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 9.84 ft / 3.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 24.61 ft / 7.50 m
- Forecastle (20 %): 19.03 ft / 5.80 m
- Mid (50 %): 19.03 ft / 5.80 m
- Quarterdeck (15 %): 9.84 ft / 3.00 m (19.03 ft / 5.80 m before break)
- Stern: 9.84 ft / 3.00 m
- Average freeboard: 18.10 ft / 5.52 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 125.3 %
- Above water (accommodation/working, high = better): 163.8 %
Waterplane Area: 15,585 Square feet or 1,448 Square metres
Displacement factor (Displacement / loading): 120 %
Structure weight / hull surface area: 83 lbs/sq ft or 403 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.93
- Longitudinal: 1.87
- Overall: 1.00
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform

She's an Ocean Scout...that can lay mines.

From the range (and the armor originally) she's designed to patrol long distances in potentially hostile regions (or combat pirates), but have the ablility to mine an area...like a pirates hideout bay, or act as a Pacific raider by mining trade routes and then waiting for the unsuspecting to arrive...to "rescue" them.

Don't we all want to 'rescue' them?
... of course we only do it for a 'certain price'.

Even without the armour, she'll still make an interesting raider. You can be assured that the Filipinos were taking notes regarding the cruise of the Emden. :-)

And carrying eight hundred depth-charges, she'd be a submarine's worst nightmare... o_O

I wouldn´t use all the misc weight for depth-charges etc. Why not use her as some kind of supply ship for DDs or submarines carrying surplus torpedos etc.?

I agree. A useful additional function for the vessel.

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I wouldn´t use all the misc weight for depth-charges etc. Why not use her as some kind of supply ship for DDs or submarines carrying surplus torpedos etc.?

Good idea. I was calculating loads using 200t of the misc weight; include the plane+cat and there's still 50t left. And of course you could carry supplies in place of some of the mine load.

An excellent idea, thanks! :-)

Remind me in the next war, to use the Tylor's guns and sink that ship.

With the lack of armour, a guy in a rowboat with a 12 guage should be enough!!

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a guy in a rowboat with a 12 gauge

Only if it's loaded with golden BBs. ^_^

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a guy in a rowboat with a 12 gauge

I'd prefer to use fire for effect of the 12 guns on the broadside....with all those mines and depth charges....it will make for some nice fireworks.