WesWorld

Cúige/Provinces-class Destroyers
- LÉ Connacht (S1) - completed 1937
- LÉ Munster (S2) - completed 1938
- LÉ Ulster (S3) - completed 1938
- LÉ Leinster (S4) - completed 1939

Contae II/County II-class Destroyers
- LÉ Contae Mhuineacháin / County Monaghan (S9) - completed 1940, sold 1942
- LÉ Contae Chill Mhantáin / County Wicklow (S10) - completed 1941, sold 1942
- LÉ Contae Cheatharlach / County Carlow (S11) - order delayed then cancelled
- LÉ Contae Shligigh / County Sligo (S12) - order delayed then cancelled

Deirdre-class Destroyers
- LÉ Deirdre (S11): Laid down in Cork January 1944, completed December 1944.
- LÉ Eithne (S12): Laid down in Cork July 1944, completed June 1945.
- LÉ Aoife (S13): Laid down in Cork January 1945, completed December 1945.
- LÉ Niamh (S14): Laid down in Cork July 1945, completed June 1946.

Summary:
Upon the formation of the Irish Naval Service, a comprehensive threat evaluation indicated that in the event of war the INS would most likely be engaged in minesweeping operations and extensive antisubmarine patrols. As a result, the Irish Naval Service sought to acquire multi-role Patrol/ASW units (such as the Deirdres). A fierce debate erupted in the Dail, however, over the INS's more controversial plan to acquire a squadron of destroyers. Eventually it was decided to build an Atlantean-designed fleet destroyer as a testbed and political trial-balloon for the Irish Naval Service.

Eventually, with relations with Britain settling satisfactorily, Ireland purchased four S-class destroyers from the Royal Navy for modernization into antisubmarine escorts. Three further vessels of the Cúige/Provinces class, started in late 1937, permitted the INS to field a full eight-ship destroyer division by mid-1939.

In 1940, a class of new destroyers of a smaller design was laid down as eventual replacements for the secondhand S-class destroyers. These ships, dubbed the "Contae IIs", were a fully modern fleet destroyer armed with six 4.5" DP guns. However, initial trials with the first ship indicated some issues with seakeeping as a result of their small size, and the final two vessels were delayed and finally cancelled. The INS quickly resold the two completed vessels to the Iraqi Navy.

On the basis of experience with their three different destroyer classes, the Irish are designing a new fleet destroyer to replace the Connacht class ships in service.

Image by thesmilingassassin and modified by Brockpaine.

Cúige-class Irish Destroyer laid down 1936

Displacement:
1,688 t light; 1,790 t standard; 2,029 t normal; 2,221 t full load

Dimensions: Length overall / water x beam x draught
394.37 ft / 385.00 ft x 36.00 ft x 12.20 ft (normal load)
120.20 m / 117.35 m x 10.97 m x 3.72 m

Armament:
8 - 5.12" / 130 mm guns (4x2 guns), 67.03lbs / 30.40kg shells, 1936 Model
Dual purpose guns in deck mounts
on centreline ends, evenly spread, 2 raised mounts - superfiring
4 - 1.57" / 40.0 mm guns (2x2 guns), 1.95lbs / 0.88kg shells, 1936 Model
Anti-aircraft guns in deck mounts
on side, all amidships, all raised mounts - superfiring
2 - 0.79" / 20.0 mm guns (1x2 guns), 0.24lbs / 0.11kg shells, 1936 Model
Anti-aircraft guns in deck mount
on side, all raised guns
4 - 0.79" / 20.0 mm guns (2x2 guns), 0.24lbs / 0.11kg shells, 1936 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
6 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1936 Model
Machine guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 546 lbs / 248 kg
Shells per gun, main battery: 200
10 - 21.0" / 533.4 mm above water torpedoes

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

- Conning tower: 1.57" / 40 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 38,156 shp / 28,464 Kw = 33.75 kts
Range 5,400nm at 15.00 kts
Bunker at max displacement = 431 tons

Complement:
150 - 196

Cost:
£1.271 million / $5.085 million

Distribution of weights at normal displacement:
Armament: 68 tons, 3.4 %
Armour: 33 tons, 1.6 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 28 tons, 1.4 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 5 tons, 0.3 %
Machinery: 891 tons, 43.9 %
Hull, fittings & equipment: 650 tons, 32.1 %
Fuel, ammunition & stores: 341 tons, 16.8 %
Miscellaneous weights: 45 tons, 2.2 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
705 lbs / 320 Kg = 10.5 x 5.1 " / 130 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.34
Metacentric height 1.8 ft / 0.6 m
Roll period: 11.2 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.46
Seaboat quality (Average = 1.00): 1.28

Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0.420
Length to Beam Ratio: 10.69 : 1
'Natural speed' for length: 22.50 kts
Power going to wave formation at top speed: 65 %
Trim (Max stability = 0, Max steadiness = 100): 55
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 25.75 ft / 7.85 m
- Forecastle (20 %): 20.50 ft / 6.25 m
- Mid (50 %): 20.50 ft / 6.25 m (12.00 ft / 3.66 m aft of break)
- Quarterdeck (15 %): 12.00 ft / 3.66 m
- Stern: 12.00 ft / 3.66 m
- Average freeboard: 16.67 ft / 5.08 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 170.7 %
- Above water (accommodation/working, high = better): 91.2 %
Waterplane Area: 8,970 Square feet or 833 Square metres
Displacement factor (Displacement / loading): 73 %
Structure weight / hull surface area: 36 lbs/sq ft or 175 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 2.24
- Overall: 0.58
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
Good seaboat, rides out heavy weather easily.

Ships in Class:
- LÉ Connacht (S1) - completed February 1937

(Remaining ships ordered to a modified design)

Image by thesmilingassassin and modified by Brockpaine.

Province-class, Irish Destroyer laid down 1937

Displacement:
1,655 t light; 1,747 t standard; 1,981 t normal; 2,168 t full load

Dimensions: Length overall / water x beam x draught
394.37 ft / 385.00 ft x 36.00 ft x 12.20 ft (normal load)
120.20 m / 117.35 m x 10.97 m x 3.72 m

Armament:
8 - 4.50" / 114 mm guns (4x2 guns), 45.00lbs / 20.41kg shells, 1937 Model
Dual purpose guns in deck mounts
on centreline ends, evenly spread, 2 raised mounts - superfiring
4 - 1.57" / 40.0 mm guns (2x2 guns), 1.95lbs / 0.88kg shells, 1937 Model
Anti-aircraft guns in deck mounts
on side, all amidships, all raised mounts - superfiring
2 - 0.79" / 20.0 mm guns (1x2 guns), 0.24lbs / 0.11kg shells, 1937 Model
Anti-aircraft guns in deck mount
on side, all raised guns
4 - 0.79" / 20.0 mm guns (2x2 guns), 0.24lbs / 0.11kg shells, 1937 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
6 - 0.66" / 16.8 mm guns in single mounts, 0.14lbs / 0.06kg shells, 1937 Model
Machine guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 370 lbs / 168 kg
Shells per gun, main battery: 250
10 - 21.0" / 533.4 mm above water torpedoes

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

- Conning tower: 1.57" / 40 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 37,316 shp / 27,837 Kw = 33.75 kts
Range 5,400nm at 15.00 kts
Bunker at max displacement = 421 tons

Complement:
147 - 192

Cost:
£1.211 million / $4.842 million

Distribution of weights at normal displacement:
Armament: 47 tons, 2.4 %
Armour: 29 tons, 1.5 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 24 tons, 1.2 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 5 tons, 0.3 %
Machinery: 891 tons, 45.0 %
Hull, fittings & equipment: 623 tons, 31.5 %
Fuel, ammunition & stores: 326 tons, 16.5 %
Miscellaneous weights: 65 tons, 3.3 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
718 lbs / 326 Kg = 15.8 x 4.5 " / 114 mm shells or 0.4 torpedoes
Stability (Unstable if below 1.00): 1.35
Metacentric height 1.8 ft / 0.6 m
Roll period: 11.2 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.31
Seaboat quality (Average = 1.00): 1.32

Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0.410
Length to Beam Ratio: 10.69 : 1
'Natural speed' for length: 22.54 kts
Power going to wave formation at top speed: 65 %
Trim (Max stability = 0, Max steadiness = 100): 53
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 25.75 ft / 7.85 m
- Forecastle (20 %): 20.50 ft / 6.25 m
- Mid (50 %): 20.50 ft / 6.25 m (12.00 ft / 3.66 m aft of break)
- Quarterdeck (15 %): 12.00 ft / 3.66 m
- Stern: 12.00 ft / 3.66 m
- Average freeboard: 16.67 ft / 5.08 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 168.0 %
- Above water (accommodation/working, high = better): 92.4 %
Waterplane Area: 8,909 Square feet or 828 Square metres
Displacement factor (Displacement / loading): 78 %
Structure weight / hull surface area: 35 lbs/sq ft or 169 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 2.22
- Overall: 0.58
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
Good seaboat, rides out heavy weather easily

[SIZE=3]Ships in Class:[/SIZE]
- LÉ Munster (S2) - 1937
- LÉ Ulster (S3) - 1938
- LÉ Leinster (S4) - 1938

[SIZE=3]Notes:[/SIZE]
The remaining three Province-class destroyers were built to a slightly modified design compared to the class leader Connacht. While Connacht carried the Atlantean-made 5.12" (130mm) dual-purpose gun, the Munster, Ulster, and Leinster were ordered with the British-manufactured 4.5" (114mm) dual-purpose gun. This change allowed the INS to save weight while increasing ammunition stowage, and answered critics concerned about ammunition availability during times of crisis. The ships are otherwise identical.

County Monaghan, Irish Destroyer laid down 1940

Displacement:
1,350 t light; 1,439 t standard; 1,646 t normal; 1,811 t full load

Dimensions: Length overall / water x beam x draught
366.17 ft / 354.33 ft x 33.46 ft x 11.48 ft (normal load)
111.61 m / 108.00 m x 10.20 m x 3.50 m

Armament:
6 - 4.50" / 114 mm guns (3x2 guns), 45.00lbs / 20.41kg shells, 1940 Model
Dual purpose guns in deck mounts
on centreline ends, majority forward, 1 raised mount - superfiring
2 - 1.57" / 40.0 mm guns (1x2 guns), 1.95lbs / 0.88kg shells, 1940 Model
Anti-aircraft guns in deck mount
on centreline aft, all raised guns - superfiring
4 - 1.57" / 40.0 mm guns in single mounts, 1.95lbs / 0.88kg shells, 1940 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
Weight of broadside 282 lbs / 128 kg
Shells per gun, main battery: 350
10 - 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 -
2nd: 0.79" / 20 mm 0.79" / 20 mm -
3rd: 0.39" / 10 mm - -

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 34,268 shp / 25,564 Kw = 33.60 kts
Range 5,500nm at 15.00 kts
Bunker at max displacement = 372 tons

Complement:
128 - 167

Cost:
£1.096 million / $4.385 million

Distribution of weights at normal displacement:
Armament: 36 tons, 2.2 %
Armour: 18 tons, 1.1 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 18 tons, 1.1 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 754 tons, 45.8 %
Hull, fittings & equipment: 477 tons, 29.0 %
Fuel, ammunition & stores: 296 tons, 18.0 %
Miscellaneous weights: 65 tons, 3.9 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
520 lbs / 236 Kg = 11.4 x 4.5 " / 114 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.29
Metacentric height 1.5 ft / 0.5 m
Roll period: 11.3 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.27
Seaboat quality (Average = 1.00): 1.06

Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0.423
Length to Beam Ratio: 10.59 : 1
'Natural speed' for length: 21.60 kts
Power going to wave formation at top speed: 67 %
Trim (Max stability = 0, Max steadiness = 100): 66
Bow angle (Positive = bow angles forward): 30.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 20.51 ft / 6.25 m
- Forecastle (20 %): 19.69 ft / 6.00 m
- Mid (35 %): 18.86 ft / 5.75 m (11.81 ft / 3.60 m aft of break)
- Quarterdeck (15 %): 12.30 ft / 3.75 m
- Stern: 13.12 ft / 4.00 m
- Average freeboard: 14.83 ft / 4.52 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 170.9 %
- Above water (accommodation/working, high = better): 111.4 %
Waterplane Area: 7,691 Square feet or 715 Square metres
Displacement factor (Displacement / loading): 75 %
Structure weight / hull surface area: 32 lbs/sq ft or 155 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 1.89
- Overall: 0.57
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

Breakdown of Miscellaneous Weights:

Ships in Class:
- LÉ Contae Mhuineacháin / County Monaghan (S9) - completed 1940
- LÉ Contae Chill Mhantáin / County Wicklow (S10) - completed 1941
- LÉ Contae Cheatharlach / County Carlow (S11) - order cancelled
- LÉ Contae Shligigh / County Sligo (S12) - order cancelled

Notes:
The two completed ships were sold to Iraq in 1942.

Deirdre-class, Irish Destroyer laid down 1944

Displacement:
2,300 t light; 2,440 t standard; 2,760 t normal; 3,016 t full load

Dimensions: Length overall / water x beam x draught
402.37 ft / 393.70 ft x 40.19 ft x 14.76 ft (normal load)
122.64 m / 120.00 m x 12.25 m x 4.50 m

Armament:
5 - 5.00" / 127 mm guns in single mounts, 55.12lbs / 25.00kg shells, 1944 Model
Dual purpose guns in deck mounts with hoists
on centreline ends, majority aft, 3 raised mounts - superfiring
8 - 1.57" / 40.0 mm guns (4x2 guns), 1.95lbs / 0.88kg shells, 1944 Model
Anti-aircraft guns in deck mounts
on side, all amidships, all raised mounts - superfiring
6 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1944 Model
Machine guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 293 lbs / 133 kg
Shells per gun, main battery: 500
10 - 21.0" / 533.4 mm above water torpedoes

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.57" / 40 mm 0.98" / 25 mm 0.98" / 25 mm

- Conning tower: 1.18" / 30 mm

Machinery:
Oil fired boilers, steam turbines plus diesel motors,
Geared drive, 2 shafts, 53,210 shp / 39,694 Kw = 35.00 kts
Range 6,500nm at 15.00 kts
Bunker at max displacement = 576 tons

Complement:
189 - 247

Cost:
£1.973 million / $7.891 million

Distribution of weights at normal displacement:
Armament: 41 tons, 1.5 %
Armour: 29 tons, 1.1 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 24 tons, 0.9 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 5 tons, 0.2 %
Machinery: 1,272 tons, 46.1 %
Hull, fittings & equipment: 838 tons, 30.3 %
Fuel, ammunition & stores: 460 tons, 16.6 %
Miscellaneous weights: 120 tons, 4.3 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
889 lbs / 403 Kg = 14.2 x 5.0 " / 127 mm shells or 0.4 torpedoes
Stability (Unstable if below 1.00): 1.19
Metacentric height 1.7 ft / 0.5 m
Roll period: 12.8 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.40
Seaboat quality (Average = 1.00): 1.17

Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.414
Length to Beam Ratio: 9.80 : 1
'Natural speed' for length: 22.94 kts
Power going to wave formation at top speed: 67 %
Trim (Max stability = 0, Max steadiness = 100): 60
Bow angle (Positive = bow angles forward): 15.00 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 %): 21.33 ft / 6.50 m
- Mid (50 %): 16.40 ft / 5.00 m
- Quarterdeck (15 %): 16.40 ft / 5.00 m
- Stern: 16.40 ft / 5.00 m
- Average freeboard: 18.74 ft / 5.71 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 167.3 %
- Above water (accommodation/working, high = better): 101.1 %
Waterplane Area: 10,195 Square feet or 947 Square metres
Displacement factor (Displacement / loading): 86 %
Structure weight / hull surface area: 40 lbs/sq ft or 194 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 2.53
- Overall: 0.58
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

Breakdown of Miscellaneous Weights:
Not yet available; includes radar.

Ships in Class:
- LÉ Deirdre (S11): Laid down in Cork January 1944, completed December 1944.
- LÉ Eithne (S12): Laid down in Cork July 1944, completed June 1945.
- LÉ Aoife (S13): Laid down in Cork January 1945, completed December 1945.
- LÉ Niamh (S12): Laid down in Cork July 1945, completed June 1946.

Notes:
Since the 5"/L38 guns are being bought separately from the US for 25t apiece, 125t was subtracted from the construction price of each ship.