WesWorld

My plans for a Mine Warfare Squadron are like this:

The 1928 cruiser-minelayer (Pluton-type) will act as squadron flagship. The squadron will be split into two flotillas, each consisting of one of the 1929 cruiser-minelayers (which I've posted previously) as leader and four Rabihorcado-class destroyers, which I will begin rebuilding in 1931 as fast minesweepers ("destroyer-minesweepers" officially), to the following design

Rabihorcado-class as built:

Quoted

Armament:
2 - 4.00" / 102 mm (2x1)
4 - 2.24" / 57.0 mm (2x2)
3 - 0.98" / 25.0 mm (3x1)
2 - 0.50" / 12.7 mm (2x1)
2 - 0.30" / 7.62 mm (2x1)

Weight of broadside 90 lbs / 41 kg
Shells per gun, main battery: 150

4 - 18.0" / 457.2 mm above water torpedoes

Depth charges @ 550lb each: 35

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 39,975 shp / 29,821 Kw = 32.76 kts
Range 4,375nm at 12.00 kts (Bunkerage = 222 tons)

Rabihorcado-class rebuilt as fast minesweeper:


Filipino Rabihorcado-class destroyer minesweeper, laid down 1923 (Engine 1931)

Displacement:
1,399 t light; 1,439 t standard; 1,574 t normal; 1,683 t full load

Dimensions: Length overall / water x beam x draught
309.64 ft / 300.00 ft x 32.00 ft x 14.00 ft (normal load)
94.38 m / 91.44 m x 9.75 m x 4.27 m

Armament:
4 - 2.95" / 75.0 mm guns (2x2 guns), 13.00lbs / 5.90kg shells, 1923 Model
Dual purpose guns in deck mounts with hoists
on centreline, all forward, 1 raised mount - superfiring
3 - 0.98" / 25.0 mm guns (1x3 guns), 0.57lbs / 0.26kg shells, 1923 Model
Anti-aircraft guns in deck mount
on centreline amidships, all raised guns - superfiring
8 - 0.54" / 13.7 mm guns (4x2 guns), 0.11lbs / 0.05kg shells, 1923 Model
Machine guns in deck mounts
on side ends, evenly spread, 2 raised mounts - superfiring

Weight of broadside 55 lbs / 25 kg
Shells per gun, main battery: 250

2 - 24.0" / 610 mm above water torpedoes

Mines @ 1,000lbs each: 60
Depth charges @ 550lb each: 75

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.18" / 30 mm 0.59" / 15 mm 0.98" / 25 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 39,921 shp / 29,781 Kw = 32.75 kts
Range 5,250nm at 12.00 kts (Bunkerage = 244 tons)

Complement:
124 - 162

Cost:
£0.513 million / $2.053 million

Distribution of weights at normal displacement:
Armament: 7 tons, 0.4 %
Armour: 6 tons, 0.4 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 6 tons, 0.4 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 870 tons, 55.3 %
Hull, fittings & equipment: 466 tons, 29.6 %
Fuel, ammunition & stores: 175 tons, 11.1 %
Miscellaneous weights: 50 tons, 3.2 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
410 lbs / 186 Kg = 31.8 x 3.0 " / 75 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.20
Metacentric height 1.3 ft / 0.4 m
Roll period: 11.9 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.15
Seaboat quality (Average = 1.00): 1.08

Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.410
Length to Beam Ratio: 9.38 : 1
'Natural speed' for length: 17.32 kts
Power going to wave formation at top speed: 71 %
Trim (Max stability = 0, Max steadiness = 100): 65
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 2.00 ft / 0.61 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 21.00 ft / 6.40 m
- Forecastle (20 %): 16.30 ft / 4.97 m
- Mid (50 %): 15.00 ft / 4.57 m
- Quarterdeck (15 %): 15.00 ft / 4.57 m
- Stern: 15.00 ft / 4.57 m
- Average freeboard: 15.83 ft / 4.83 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 185.4 %
- Above water (accommodation/working, high = better): 113.5 %
Waterplane Area: 5,945 Square feet or 552 Square metres
Displacement factor (Displacement / loading): 63 %
Structure weight / hull surface area: 34 lbs/sq ft or 164 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 3.83
- Overall: 0.61
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

Personally I think it would be a waste of time and material to convert these ships. They are too slow and the torpedo's are absolutely useless with only two of them. A purpose built design would fare better.

Ordinarily I'd agree, but (a) it's "cheaper" to rebuild and (b) these ships will have been superceded as DDs by that point anyway, so I need to find something to do with them. ^_^

As for the fish, they're included for the same reasons Rocky put them on his latest minelayers. :-)

And as for speed...since most minesweepers max out at ~20kts, I don't think they're all too slow. ;-)

You put torpedos on your minesweepers because somebody in the Indian Naval Design Bureau thought it was a good idea? Cool. I wish more people did things this way.

A little confused on the Rabihorcado class - are they sweepers or layers? Because nothing about the Rabihorcado rebuild says "sweeper" to me. An eight hundred ton ship with one big gun and twenty knots speed says "sweeper" to me.

Question to the board at large: was it common practice historically to put sweepers and layers in a common command structure? I'd have expected that their very different missions would see them under different commands.

Quoted

A little confused on the Rabihorcado class - are they sweepers or layers? Because nothing about the Rabihorcado rebuild says "sweeper" to me. An eight hundred ton ship with one big gun and twenty knots speed says "sweeper" to me.

Well, both actually. The conversion is intended to make the ships into something like the OTL USN fast minesweepers converted from DDs during WW2. However they also have the capability to lay mines as well, and also to act as fast DEs when not mine-whatevering.

...Targets.

With Chile's stand against mine warfare, I'd assume they would target minelayers quickly to deny that advantage to any enemy.

Quoted

With Chile's stand against mine warfare, I'd assume they would target minelayers quickly to deny that advantage to any enemy.

Japan is not too fond of Mine warfare either (depspite having a bunch of mine layers). Might not be a bad idea to target the minelayers as fast as possible.

I'm sure India is no fan of having mines sink its ships, but it makes for a great equalizer against bigger navies. Hence the introduction of purpose-built minelayers into the navy.

This force seems oriented toward 'offensive' mine warfare. You have relatively fast ships that can be deployed to lay mines to support offensive operations or conduct high speed mine clearance in support of these operations.

I don't know where WesWorld is in terms of magnetic mines. These ships would be vulnerable.

You would ideally need a complementary force of smaller, wooden hulled minesweepers to support localized operations and protect local resources.

Quoted

This force seems oriented toward 'offensive' mine warfare. You have relatively fast ships that can be deployed to lay mines to support offensive operations or conduct high speed mine clearance in support of these operations.

This is way I'd classify them as targets in times of war. Of course they could be as much danger to themselves as to any enemy they plan to mine.

As Offensive minelayers they would need more speed than a mere 20 knots and if the TT's are to ward off the enemy even 18" would be enough to do that so the measly 2x 24' TT's are not enough IMO to hit anything.

4x18" would give you a better ROF for a defensive torpedo spread, your certainly not goint to sink the enemy ship unless you entice them into your freshly laid minefield, so its better to force them to take evasive action or damage them enough for you to flee.

Personally I find the TT's useless, but whatever works for ya.

Quoted

You would ideally need a complementary force of smaller, wooden hulled minesweepers to support localized operations and protect local resources.

Indeed. I've got 15 of those already. :-)

Quoted

As Offensive minelayers they would need more speed than a mere 20 knots

???

"Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 39,921 shp / 29,781 Kw = 32.75 kts
Range 5,250nm at 12.00 kts (Bunkerage = 244 tons)"

Quoted

so its better to force them to take evasive action or damage them enough for you to flee.

...which is exactly the point. Not so much as to have a high PK%, but to force the enemy to turn to avoid the fish.

Will a quad 18" torpedo mount fit in roughly the same space as a twin 24"?

Cripes if you would stick to a design, I could acctually accurately comment on her design!!!

Quoted

Will a quad 18" torpedo mount fit in roughly the same space as a twin 24"?

I'm sure it would, you'd also fire off more fish too..

Quoted

Originally posted by thesmilingassassin
Cripes if you would stick to a design, I could acctually accurately comment on her design!!!

Huh? I didn't change anything...



Ah, I think this caused the confusion:

"And as for speed...since most minesweepers max out at ~20kts, I don't think they're all too slow."

What I meant was most other minesweepers are capable of 20kts max, so these ships, being capable of 32 and change, aren't all too slow.

Quoted

Originally posted by The Rock Doctor
Question to the board at large: was it common practice historically to put sweepers and layers in a common command structure? I'd have expected that their very different missions would see them under different commands.

Good question.

As I see it minesweepers were organized in common command structure. Mine layers however often were not. Reason is: There weren´t that many purpose-build minelayers anyway.

So the individual ships were attached to a regional command, not to a unit/squadron. For example the Oberbefehlshaber Ostsee had access to mine layers which where attached directly to his command. During operations they were then under local command of whoever was in charge for the operation.

This is of course only one way to handle it. Other minelayers, especially those converted during wartimes for this purpose to get higher numbers or those otherwise acting as CLs, were part of the standard fleet organisations - at least in the German Navy.

Hopefully somebody else has more information at hand...