WesWorld

[SIZE=3]Deirdre-class, Irish Destroyer laid down 1941[/SIZE]

Displacement:
2,400 t light; 2,568 t standard; 3,147 t normal; 3,610 t full load

Dimensions: Length overall / water x beam x draught
437.40 ft / 426.51 ft x 42.98 ft x 12.80 ft (normal load)
133.32 m / 130.00 m x 13.10 m x 3.90 m

Armament:
6 - 4.50" / 114 mm guns (3x2 guns), 45.00lbs / 20.41kg shells, 1941 Model
Dual purpose guns in deck mounts with hoists
on centreline ends, majority forward, 1 raised mount - superfiring
4 - 1.57" / 40.0 mm guns (2x2 guns), 1.95lbs / 0.88kg shells, 1941 Model
Anti-aircraft guns in deck mounts
on side, all amidships, all raised mounts - superfiring
2 - 1.57" / 40.0 mm guns in single mounts, 1.95lbs / 0.88kg shells, 1941 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
4 - 0.66" / 16.8 mm guns in single mounts, 0.14lbs / 0.06kg shells, 1941 Model
Machine guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 282 lbs / 128 kg
Shells per gun, main battery: 650
5 - 21.0" / 533.4 mm above water torpedoes

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.18" / 30 mm 0.79" / 20 mm 0.79" / 20 mm
2nd: 0.79" / 20 mm 0.39" / 10 mm -
3rd: 0.79" / 20 mm 0.39" / 10 mm -
4th: 0.59" / 15 mm - -

- Conning tower: 1.18" / 30 mm

Machinery:
Oil fired boilers, steam turbines plus diesel motors,
Geared drive, 2 shafts, 51,363 shp / 38,317 Kw = 34.00 kts
Range 7,000nm at 18.00 kts
Bunker at max displacement = 1,043 tons

Complement:
209 - 273

Cost:
£1.879 million / $7.518 million

Distribution of weights at normal displacement:
Armament: 36 tons, 1.1 %
Armour: 26 tons, 0.8 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 20 tons, 0.6 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 5 tons, 0.2 %
Machinery: 1,357 tons, 43.1 %
Hull, fittings & equipment: 861 tons, 27.4 %
Fuel, ammunition & stores: 747 tons, 23.7 %
Miscellaneous weights: 120 tons, 3.8 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
1,237 lbs / 561 Kg = 27.1 x 4.5 " / 114 mm shells or 0.5 torpedoes
Stability (Unstable if below 1.00): 1.34
Metacentric height 2.4 ft / 0.7 m
Roll period: 11.7 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.23
Seaboat quality (Average = 1.00): 1.12

Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0.470
Length to Beam Ratio: 9.92 : 1
'Natural speed' for length: 23.67 kts
Power going to wave formation at top speed: 66 %
Trim (Max stability = 0, Max steadiness = 100): 63
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 1.64 ft / 0.50 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 25.43 ft / 7.75 m
- Forecastle (25 %): 22.97 ft / 7.00 m
- Mid (50 %): 20.51 ft / 6.25 m (13.12 ft / 4.00 m aft of break)
- Quarterdeck (15 %): 13.12 ft / 4.00 m
- Stern: 13.12 ft / 4.00 m
- Average freeboard: 17.98 ft / 5.48 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 155.1 %
- Above water (accommodation/working, high = better): 152.8 %
Waterplane Area: 12,354 Square feet or 1,148 Square metres
Displacement factor (Displacement / loading): 100 %
Structure weight / hull surface area: 39 lbs/sq ft or 190 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.51
- Longitudinal: 1.51
- Overall: 0.57
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

My first reaction is that the vessel seems very large for the proposed armament. I would think that the gun and torpedo outfit could be carried in a smaller ship. Are there particular reasons for choosing a hull of such dimensions?

Quoted

Originally posted by BruceDuncan
My first reaction is that the vessel seems very large for the proposed armament. I would think that the gun and torpedo outfit could be carried in a smaller ship. Are there particular reasons for choosing a hull of such dimensions?

It absolutely can be carried in a smaller ship - the Contae-II class destroyer the Irish are currently building is 1,350 tons light and carries the same armament. Actually, it carries more armament - ten torpedo tubes instead of five. However, the builders trials of the Contae and the performance of the Province-class in the NATO exercise have sparked an interest in designing a larger ship with superior seakeeping characteristics. There was also an interest in trying out a CODAS plant, with B+W diesels for economy cruising and auxiliary steam turbines for dash speeds.

The storm damage taken by the Irish vessels in the last NATO exercise would give pause and would be good reason to consider a larger vessel with superior sea-keeping abilities.

Also, as Ireland does not seem intent on maximizing numbers, it is reasonable to investigate 'quality'. It will be interesting to see how she fares in service.

Well, since it's still a design study, I'm still considering it. It *is* a pretty hefty ship, after all.

At the same time, the Irish haven't had any great difficulties with the 1,343-ton LÉ Shannon, though the Irish chalk that up to her lower Length-vs-beam ratio (compared to the Contaes and Provinces).

Found this in my image folder and cleaned it up for post. No specs, just a drawing. I'm not even sure what the main guns are, but they look like smaller versions of the twin 6" German turrets.

Went back over the originally-posted design and gave it a bit of a makeover.

Quoted

[SIZE=3]Deirdre, Irish Destroyer laid down 1944[/SIZE]

Displacement:
2,463 t light; 2,657 t standard; 3,274 t normal; 3,768 t full load

Dimensions: Length overall / water x beam x draught
447.55 ft / 436.35 ft x 44.62 ft x 12.80 ft (normal load)
136.41 m / 133.00 m x 13.60 m x 3.90 m

Armament:
6 - 4.50" / 114 mm guns (3x2 guns), 45.00lbs / 20.41kg shells, 1944 Model
Dual purpose guns in deck mounts with hoists
on centreline ends, majority forward, 1 raised mount - superfiring
8 - 1.57" / 40.0 mm guns (4x2 guns), 1.95lbs / 0.89kg shells, 1944 Model
Anti-aircraft guns in deck mounts
on side, all amidships, all raised mounts - superfiring
4 - 1.57" / 40.0 mm guns (1x4 guns), 1.95lbs / 0.89kg shells, 1944 Model
Anti-aircraft guns in deck mount
on centreline aft, all raised guns - superfiring
4 - 0.66" / 16.8 mm guns in single mounts, 0.14lbs / 0.07kg shells, 1944 Model
Machine guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 294 lbs / 133 kg
Shells per gun, main battery: 750
5 - 21.0" / 533.4 mm above water torpedoes

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.18" / 30 mm 0.79" / 20 mm 0.79" / 20 mm
2nd: 0.79" / 20 mm 0.39" / 10 mm -
3rd: 0.79" / 20 mm 0.39" / 10 mm -
4th: 0.59" / 15 mm - -

- Conning tower: 1.18" / 30 mm

Machinery:
Oil fired boilers, steam turbines plus diesel motors,
Geared drive, 2 shafts, 51,813 shp / 38,652 Kw = 34.00 kts
Range 7,500nm at 18.00 kts
Bunker at max displacement = 1,110 tons

Complement:
216 - 281

Cost:
£2.036 million / $8.144 million

Distribution of weights at normal displacement:
Armament: 37 tons, 1.1 %
Armour: 28 tons, 0.9 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 22 tons, 0.7 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 6 tons, 0.2 %
Machinery: 1,323 tons, 40.4 %
Hull, fittings & equipment: 915 tons, 27.9 %
Fuel, ammunition & stores: 811 tons, 24.8 %
Miscellaneous weights: 160 tons, 4.9 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
1,447 lbs / 656 Kg = 31.8 x 4.5 " / 114 mm shells or 0.5 torpedoes
Stability (Unstable if below 1.00): 1.34
Metacentric height 2.5 ft / 0.8 m
Roll period: 11.8 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.22
Seaboat quality (Average = 1.00): 1.17

Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0.460
Length to Beam Ratio: 9.78 : 1
'Natural speed' for length: 24.00 kts
Power going to wave formation at top speed: 65 %
Trim (Max stability = 0, Max steadiness = 100): 60
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 1.64 ft / 0.50 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 26.25 ft / 8.00 m
- Forecastle (25 %): 23.79 ft / 7.25 m
- Mid (50 %): 21.33 ft / 6.50 m (13.78 ft / 4.20 m aft of break)
- Quarterdeck (15 %): 13.78 ft / 4.20 m
- Stern: 13.78 ft / 4.20 m
- Average freeboard: 18.72 ft / 5.71 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 148.2 %
- Above water (accommodation/working, high = better): 164.7 %
Waterplane Area: 13,011 Square feet or 1,209 Square metres
Displacement factor (Displacement / loading): 105 %
Structure weight / hull surface area: 39 lbs/sq ft or 192 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 1.56
- Overall: 0.56
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

And a large minesweeper/patrol ship.

Quoted

[SIZE=3]Morrigan, Irish Minesweeper laid down 1942[/SIZE]

Displacement:
798 t light; 833 t standard; 1,040 t normal; 1,205 t full load

Dimensions: Length overall / water x beam x draught
232.78 ft / 229.66 ft x 31.82 ft x 10.83 ft (normal load)
70.95 m / 70.00 m x 9.70 m x 3.30 m

Armament:
1 - 3.70" / 94.0 mm guns in single mounts, 25.33lbs / 11.49kg shells, 1942 Model
Dual purpose gun in a deck mount with hoist
on centreline forward
2 - 1.57" / 40.0 mm guns (1x2 guns), 1.95lbs / 0.88kg shells, 1942 Model
Anti-aircraft guns in deck mount
on centreline aft
8 - 0.79" / 20.0 mm guns (4x2 guns), 0.24lbs / 0.11kg shells, 1942 Model
Machine guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 31 lbs / 14 kg
Shells per gun, main battery: 750

Machinery:
Diesel Internal combustion motors,
Geared drive, 2 shafts, 3,093 shp / 2,307 Kw = 18.00 kts
Range 6,500nm at 15.00 kts
Bunker at max displacement = 372 tons

Complement:
91 - 119

Cost:
£0.270 million / $1.082 million

Distribution of weights at normal displacement:
Armament: 4 tons, 0.4 %
Machinery: 81 tons, 7.8 %
Hull, fittings & equipment: 533 tons, 51.2 %
Fuel, ammunition & stores: 242 tons, 23.3 %
Miscellaneous weights: 180 tons, 17.3 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
2,795 lbs / 1,268 Kg = 110.3 x 3.7 " / 94 mm shells or 1.5 torpedoes
Stability (Unstable if below 1.00): 1.12
Metacentric height 1.1 ft / 0.3 m
Roll period: 12.7 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.07
Seaboat quality (Average = 1.00): 2.00

Hull form characteristics:
Hull has raised forecastle, rise forward of midbreak
Block coefficient: 0.460
Length to Beam Ratio: 7.22 : 1
'Natural speed' for length: 15.15 kts
Power going to wave formation at top speed: 52 %
Trim (Max stability = 0, Max steadiness = 100): 35
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: 17.72 ft / 5.40 m
- Forecastle (20 %): 18.04 ft / 5.50 m (17.06 ft / 5.20 m aft of break)
- Mid (45 %): 16.40 ft / 5.00 m (8.53 ft / 2.60 m aft of break)
- Quarterdeck (15 %): 8.53 ft / 2.60 m
- Stern: 8.53 ft / 2.60 m
- Average freeboard: 12.46 ft / 3.80 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 49.4 %
- Above water (accommodation/working, high = better): 115.0 %
Waterplane Area: 4,701 Square feet or 437 Square metres
Displacement factor (Displacement / loading): 279 %
Structure weight / hull surface area: 63 lbs/sq ft or 307 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.32
- Longitudinal: 5.34
- Overall: 1.51
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
Excellent seaboat, comfortable, can fire her guns in the heaviest weather

[SIZE=3]The Ideal Irish Naval Service, 1946[/SIZE]

I've been considering what sort of goals I'd like to reach moving forward with the Irish Naval Service. To some extent that's wrapped up in my ideas of what the "ideal navy" is for them. As I've stated on previous occasions, the Irish Naval Service is primarily engineered to serve in a trade protection role alongside the Royal Navy. This means that the force is engineered to undertake several roles:
- Antisubmarine warfare in support of convoy operations
- Defense against surface commerce raiders
- Creation of defensive mine barrages
- Sweeping of enemy minefields

Peacetime roles revolve around the continued policing of the coastal fisheries, search and rescue, and enforcement of the sea borders.

At present, the main combat strength of the INS is composed of one heavy cruiser, six modern destroyers, four old destroyers (soon to be retired), ten submarines, and four frigates / sloops, with three further vessels under construction. There are a number of smaller vessels and auxiliaries, which I shall not touch on here. I deem the size of the current force somewhat excessive, considering the political situation in western Europe; however, the four ex-British destroyers shall be scrapped soon, and with the completion of the next three Shannon class frigates, there may be the possibility of shuffling off some of the current sloops in turn.

Most of the current warships used by the Irish Naval Service were acquired with a bit of an... experimental air about them. As the Irish in 1936 had relatively limited ideas of what they wanted or needed, some mistakes were made - instances where I took the easy road for the sake of the fast build-up. The learning experience has been beneficial, and now it is time to move forward from there. I feel that the current budget - two factories worth - could tempt a player to over-build the fleet. In other words, I feel it's possible, but undesirable, to keep building ships with the out-of-character reason of "well, I've got money to spend, so I'll build ___ to use it up!" Since I'm in the somewhat enviable position of having a budget greater than my needs dictate, part of the side-effect is that my ships will be replaced relatively early in their service lives, and will probably be refitted on a much more regular basis than ships elsewhere in Wesworld. (A case in point is the destroyer Connacht, which was laid down in April 1936, and has already returned to the yard three times for a refit.)

That leads me to define what I see as the "ideal Irish fleet":
- 1 heavy cruiser
- 4 fleet destroyers
- 4 ASW frigates
- 4 minesweeper/patrol ships
- 2 fisheries sloops
- coastal forces

The purchase of the old USS Salt Lake City, now Granuaile, was one of the easy roads taken, but it's proven to be one of the good ones. While she's still a tinclad, she's capable of decisively trouncing many light cruisers and all armed merchant cruisers, which is precisely what the Irish wanted. At the present time, the plan is to maintain the Granuaile in top notch working condition, keeping her updated so much as possible within the budget. At the moment, I do not foresee a need for a replacement vessel.

For fleet destroyers, you might say I've already got that detail worked out - four Province class destroyers, backed by two modern Contae II class destroyers. The Provinces have proven to be pretty good ships all told - seaworthy, well-armed, and useful - but the INS is already having a few reservations about seakeeping on the new Contae II class. While I theoretically have this base well covered for now, a replacement destroyer (see above) is still highly likely. The main reason for this will be seakeeping and keeping everything modern. Though this is OOC foresight, I expect that by 1944, I'll probably be able to buy some sort of new ASW weapon system such as Squid or Hedgehog off the shelf. There may be a point for the Irish where it'll be easier to build a new ship rather than refit even relatively new ones.

I've already got a pretty satisfactory ASW frigate in the form of the Shannon class sloops. At the present time I don't see that changing, although the introduction of new ASW weapon systems may alter those plans a bit.

The final two categories, minesweepers and fisheries sloops, are where I'm going to focus in the immediate future. The current fisheries sloops are relatively small, and while they are not in immediate need of replacement, they are fairly high on the list. Similarly, Ireland's minesweeper fleet is composed exclusively of eight very small ships, all under two hundred tons. While they've proven highly satisfactory, they're not really designed for oceanic operation, and a larger minesweeper - with a bit of ASW patrol ship capability added in - is similarly important.

An idea with all the extra cash lying around is to build extra frigates but then place them immediately in reserve. Therefore, creating a force that is cheap to maintain in peacetime but can be immediately put to use in wartime. An escort carrier and a pocket battleship (OTL German style) could be useful too.

Your outline plan for the Irish Naval Service looks very good.

Of the ships in service, the only one which looks out of place is the Granuaille - and I understand the IC ratiionale behind her acquisition; it merely looks odd. Replacing her with a pocket battleship would make no sense; you're creating a commerce protection force, not a commerce raiding force.

In a sense, having a small aircraft carrier could make sense, but if the INS confines itself to the Western and Northern Approaches, land-based air assets can obviate the need for carrier aviation. Of course, it the Royal Navy were to offer one gratis, it might be worth considering.

I've looked at your frigate and destroyer designs and I think they are well suited to the type of missions you envision. Acquiring a standoff ASW weapon when they become available will enhance their ability while influencing design choices for replacements, as you've already noticed.

I agree that an oceanic minesweeper that could also function as an AA and/or ASW escort would be an excellent addition to your force mix - something in the 600-800 tons range, fitted with sonar and appropriate gun armament, and capable of carrying a basic AS outfit would be best I think.

One thought to consider that while generally operating close to home, it may be necessary to refuel at sea while carrying out operations. Acquisition of a small support tanker - like those building in Germany and elsewhere - could be beneficial. I'm envisioning something around 2,000 tons light or so, sized to refuel a small escort group and resupply them with the basics to maintain their time on station, not so much to increase their operational radius.

Those are my thoughts.

Looks well balanced.
I'd agree with Bruce on the idea of a support tanker. I don't think a carrier would enhance the role of the Navy, esp in peacetime, but in a general European war a small Escort Carrier like the OTL Casablanca might be useful.

The above destroyer and sloop designs look fine to me. I'd like to add that Ireland has access to whatever goodies it needs, usually perhaps a year behind RN introduction but I'm willing to lessen this period for certain items. The RN is now experimenting with ahead weapons (Parsnip).

I didn't touch any on auxiliaries; I mainly wished to address the combat side of the INS. I've got some plans for auxiliary ships, however.

An escort carrier doesn't serve my needs or interests at the present time. There's no interest in the Irish Air Corps to expand the naval aviation side of their duties any further than the current floatplanes, flying boats, and maritime patrol aircraft If a major war started, it would be considered - but unless that happens, I don't see it being justifiable.

Quoted

Originally posted by Desertfox
An idea with all the extra cash lying around is to build extra frigates but then place them immediately in reserve. Therefore, creating a force that is cheap to maintain in peacetime but can be immediately put to use in wartime.-

Actually, I'd had a similar thought - developing an ASW trawler design, building a number of them, and then renting them out (unarmed) to the civilian sector during peacetime. In wartime, call them up, load aboard the guns and DCs and a crew, and they're in service...

Went ahead and put together some various ideas for a small unrep ship.

Quoted

[SIZE=3]Flidais, Irish Underway Replenishment Ship laid down 1942[/SIZE]

Displacement:
4,477 t light; 4,800 t standard; 11,535 t normal; 16,922 t full load

Dimensions: Length overall / water x beam x draught
475.72 ft / 475.72 ft x 59.06 ft x 23.95 ft (normal load)
145.00 m / 145.00 m x 18.00 m x 7.30 m

Armament:
4 - 3.70" / 94.0 mm guns (2x2 guns), 25.33lbs / 11.49kg shells, 1942 Model
Dual purpose guns in deck mounts with hoists
on centreline ends, evenly spread
24 - 1.57" / 40.0 mm guns (2x12 guns), 1.95lbs / 0.89kg shells, 1942 Model
Anti-aircraft guns in deck mounts
on side, all amidships, all raised mounts - superfiring
12 - 0.79" / 20.0 mm guns (6x2 guns), 0.24lbs / 0.11kg shells, 1942 Model
Machine guns in deck mounts
on side, evenly spread
Weight of broadside 151 lbs / 69 kg
Shells per gun, main battery: 900

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Ends: Unarmoured

- Torpedo Bulkhead:
0.79" / 20 mm 360.89 ft / 110.00 m 23.95 ft / 7.30 m

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.98" / 25 mm 0.59" / 15 mm -
2nd: 0.59" / 15 mm 0.39" / 10 mm -

- Conning tower: 0.98" / 25 mm

Machinery:
Oil fired boilers, steam turbines plus diesel motors,
Electric motors, 2 shafts, 11,306 shp / 8,435 Kw = 18.00 kts
Range 35,000nm at 18.00 kts
Bunker at max displacement = 12,122 tons

Complement:
556 - 723

Cost:
£1.361 million / $5.445 million

Distribution of weights at normal displacement:
Armament: 19 tons, 0.2 %
Armour: 274 tons, 2.4 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 252 tons, 2.2 %
- Armament: 11 tons, 0.1 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 11 tons, 0.1 %
Machinery: 295 tons, 2.6 %
Hull, fittings & equipment: 2,644 tons, 22.9 %
Fuel, ammunition & stores: 7,057 tons, 61.2 %
Miscellaneous weights: 1,245 tons, 10.8 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
55,373 lbs / 25,117 Kg = 2,186.4 x 3.7 " / 94 mm shells or 14.4 torpedoes
Stability (Unstable if below 1.00): 1.56
Metacentric height 4.8 ft / 1.5 m
Roll period: 11.3 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.02
Seaboat quality (Average = 1.00): 2.00

Hull form characteristics:
Hull has raised forecastle, raised quarterdeck
Block coefficient: 0.600
Length to Beam Ratio: 8.06 : 1
'Natural speed' for length: 21.81 kts
Power going to wave formation at top speed: 38 %
Trim (Max stability = 0, Max steadiness = 100): 35
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: 26.25 ft / 8.00 m
- Forecastle (15 %): 23.79 ft / 7.25 m (16.40 ft / 5.00 m aft of break)
- Mid (50 %): 16.40 ft / 5.00 m
- Quarterdeck (20 %): 23.79 ft / 7.25 m (16.40 ft / 5.00 m before break)
- Stern: 26.25 ft / 8.00 m
- Average freeboard: 19.38 ft / 5.91 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 35.9 %
- Above water (accommodation/working, high = better): 115.5 %
Waterplane Area: 20,547 Square feet or 1,909 Square metres
Displacement factor (Displacement / loading): 510 %
Structure weight / hull surface area: 79 lbs/sq ft or 384 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.94
- Longitudinal: 1.61
- 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
Excellent seaboat, comfortable, can fire her guns in the heaviest weather

Notes:
The TDS is simmed to simulate the ship having a double bottom hull to survive wave action or damage, etc.

An interesting design and an interesting approach to the problem of a naval auxiliary.

I'm thinking though that the INS might be better off with two of something smaller than one large replenishment ship like this. Also, the AA outfit looks a bit on the heavy side - trying to imagine where the twelve 40mm mounts would fit among all the RAS hoists and equipment.

Just my two cents

It depends if the INS is going to field one large ASW force or a couple of smaller task forces. I would say one tanker would suffice to support a large group, two small ships would cost more to operate and would be a luxury in peacetime.

The 40mm problem could be solved by using qaud mounts.

Quoted

Originally posted by Hood
The 40mm problem could be solved by using qaud mounts.

...as opposed to the 12-gun mounts I seem to have used. Oops!

Quoted

Originally posted by Hood
It depends if the INS is going to field one large ASW force or a couple of smaller task forces. I would say one tanker would suffice to support a large group, two small ships would cost more to operate and would be a luxury in peacetime.

The 40mm problem could be solved by using qaud mounts.

Two smaller ships are not, ipso facto, more expensive to operate than one larger vessel; it depends on the relative size, manning levels, and capabilities of the competing designs.

The single large vessel has two potential drawbacks - it can only be in one place at a time (which admittedly is not a problem if the INS plans but a single task group) and it is either operational or not. Having two vessels allows one to undergo refit or repair while the other continues to support operations.

Is redundancy in peacetime a luxury? Perhaps. In wartime it is priceless.

Well, let's throw a smaller one out there, then.

Quoted

[SIZE=3]Deichtine, Irish Tiny Tanker laid down 1942[/SIZE]

Displacement:
3,730 t light; 3,976 t standard; 8,373 t normal; 11,890 t full load

Dimensions: Length overall / water x beam x draught
424.58 ft / 410.11 ft x 55.77 ft x 23.29 ft (normal load)
129.41 m / 125.00 m x 17.00 m x 7.10 m

Armament:
4 - 3.70" / 94.0 mm guns (2x2 guns), 25.33lbs / 11.49kg shells, 1942 Model
Dual purpose guns in deck mounts with hoists
on centreline ends, evenly spread
16 - 1.57" / 40.0 mm guns (4x4 guns), 1.95lbs / 0.89kg shells, 1942 Model
Anti-aircraft guns in deck mounts
on side, all amidships, all raised mounts - superfiring
8 - 0.79" / 20.0 mm guns (4x2 guns), 0.24lbs / 0.11kg shells, 1942 Model
Machine guns in deck mounts
on side, evenly spread
Weight of broadside 135 lbs / 61 kg
Shells per gun, main battery: 900

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Ends: Unarmoured

- Torpedo Bulkhead:
0.79" / 20 mm 393.70 ft / 120.00 m 29.53 ft / 9.00 m

Machinery:
Oil fired boilers, steam turbines plus diesel motors,
Electric motors, 1 shaft, 6,931 shp / 5,171 Kw = 16.50 kts
Range 37,000nm at 16.00 kts
Bunker at max displacement = 7,915 tons

Complement:
436 - 568

Cost:
£1.082 million / $4.328 million

Distribution of weights at normal displacement:
Armament: 17 tons, 0.2 %
Armour: 339 tons, 4.0 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 339 tons, 4.0 %
- Armament: 0 tons, 0.0 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 181 tons, 2.2 %
Hull, fittings & equipment: 1,943 tons, 23.2 %
Fuel, ammunition & stores: 4,643 tons, 55.5 %
Miscellaneous weights: 1,250 tons, 14.9 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
32,968 lbs / 14,954 Kg = 1,301.7 x 3.7 " / 94 mm shells or 9.7 torpedoes
Stability (Unstable if below 1.00): 1.41
Metacentric height 3.8 ft / 1.2 m
Roll period: 12.0 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.03
Seaboat quality (Average = 1.00): 2.00

Hull form characteristics:
Hull has raised forecastle, raised quarterdeck
Block coefficient: 0.550
Length to Beam Ratio: 7.35 : 1
'Natural speed' for length: 20.25 kts
Power going to wave formation at top speed: 37 %
Trim (Max stability = 0, Max steadiness = 100): 35
Bow angle (Positive = bow angles forward): 10.00 degrees
Stern overhang: 9.84 ft / 3.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 26.25 ft / 8.00 m
- Forecastle (20 %): 22.97 ft / 7.00 m (15.42 ft / 4.70 m aft of break)
- Mid (50 %): 15.42 ft / 4.70 m
- Quarterdeck (15 %): 22.97 ft / 7.00 m (15.42 ft / 4.70 m before break)
- Stern: 24.61 ft / 7.50 m
- Average freeboard: 18.45 ft / 5.62 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 42.5 %
- Above water (accommodation/working, high = better): 104.3 %
Waterplane Area: 15,482 Square feet or 1,438 Square metres
Displacement factor (Displacement / loading): 402 %
Structure weight / hull surface area: 73 lbs/sq ft or 358 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.92
- Longitudinal: 2.04
- 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
Excellent seaboat, comfortable, can fire her guns in the heaviest weather

Meteorite, Irish Tanker laid down 1942

Displacement:
2,210 t light; 2,351 t standard; 4,371 t normal; 5,987 t full load

Dimensions: Length overall / water x beam x draught
343.12 ft / 336.29 ft x 48.23 ft x 16.40 ft (normal load)
104.58 m / 102.50 m x 14.70 m x 5.00 m

Armament:
4 - 3.70" / 94.0 mm guns (2x2 guns), 25.33lbs / 11.49kg shells, 1942 Model
Dual purpose guns in deck mounts with hoists
on centreline ends, evenly spread
12 - 0.79" / 20.0 mm guns (6x2 guns), 0.24lbs / 0.11kg shells, 1942 Model
Machine guns in deck mounts
on side, all amidships
Weight of broadside 104 lbs / 47 kg
Shells per gun, main battery: 900

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.98" / 25 mm 0.59" / 15 mm -
2nd: 0.59" / 15 mm 0.39" / 10 mm -

- Conning tower: 0.98" / 25 mm

Machinery:
Oil fired boilers, steam turbines plus diesel motors,
Electric motors, 1 shaft, 3,474 shp / 2,592 Kw = 15.00 kts
Range 28,400nm at 15.00 kts
Bunker at max displacement = 3,635 tons

Complement:
268 - 349

Cost:
£0.643 million / $2.571 million

Distribution of weights at normal displacement:
Armament: 13 tons, 0.3 %
Armour: 15 tons, 0.3 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 9 tons, 0.2 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 6 tons, 0.1 %
Machinery: 91 tons, 2.1 %
Hull, fittings & equipment: 1,092 tons, 25.0 %
Fuel, ammunition & stores: 2,161 tons, 49.4 %
Miscellaneous weights: 1,000 tons, 22.9 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
13,074 lbs / 5,930 Kg = 516.2 x 3.7 " / 94 mm shells or 3.6 torpedoes
Stability (Unstable if below 1.00): 1.29
Metacentric height 2.6 ft / 0.8 m
Roll period: 12.5 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.04
Seaboat quality (Average = 1.00): 2.00

Hull form characteristics:
Hull has raised forecastle, raised quarterdeck
Block coefficient: 0.575
Length to Beam Ratio: 6.97 : 1
'Natural speed' for length: 18.34 kts
Power going to wave formation at top speed: 38 %
Trim (Max stability = 0, Max steadiness = 100): 35
Bow angle (Positive = bow angles forward): 10.00 degrees
Stern overhang: 2.50 ft / 0.76 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 24.61 ft / 7.50 m
- Forecastle (20 %): 19.69 ft / 6.00 m (12.47 ft / 3.80 m aft of break)
- Mid (50 %): 12.47 ft / 3.80 m
- Quarterdeck (20 %): 19.69 ft / 6.00 m (12.47 ft / 3.80 m before break)
- Stern: 19.69 ft / 6.00 m
- Average freeboard: 15.75 ft / 4.80 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 36.4 %
- Above water (accommodation/working, high = better): 100.0 %
Waterplane Area: 11,287 Square feet or 1,049 Square metres
Displacement factor (Displacement / loading): 336 %
Structure weight / hull surface area: 60 lbs/sq ft or 294 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.93
- Longitudinal: 1.93
- 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
Excellent seaboat, comfortable, can fire her guns in the heaviest weather