WesWorld

Taking the Shakespeare class leaders as a model and designing to the 1600ton limit set by the CT the RN started with a trial class of 4 ships, the X class. With the abandoned large destroyers adoption of the 4.5" gun these ships incorporated 5 guns on the same layout as the late war leaders but were 200tons lighter. They also employed a transome stern after the success of the I class battlecruisers.

X Class, GB Destroyer laid down 1926

Displacement:
1,528 t light; 1,585 t standard; 1,740 t normal; 1,863 t full load

Dimensions: Length overall / water x beam x draught
375.00 ft / 375.00 ft x 33.00 ft x 12.30 ft (normal load)
114.30 m / 114.30 m x 10.06 m x 3.75 m

Armament:
5 - 4.50" / 114 mm guns in single mounts, 45.56lbs / 20.67kg shells, 1926 Model
Quick firing guns in deck mounts with hoists
on centreline ends, majority forward, all raised mounts - superfiring
1 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1926 Model
Anti-aircraft gun in deck mount
on side amidships, 1 raised gun
4 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1926 Model
Machine guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 260 lbs / 118 kg
Shells per gun, main battery: 150
6 - 21.0" / 533.4 mm above water torpedoes

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.50" / 13 mm - -

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 35,581 shp / 26,544 Kw = 34.00 kts
Range 5,500nm at 12.00 kts (Bunkerage = 279 tons)

Complement:
134 - 175

Cost:
£0.699 million / $2.797 million

Distribution of weights at normal displacement:
Armament: 33 tons, 1.9 %
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: 869 tons, 50.0 %
Hull, fittings & equipment: 530 tons, 30.5 %
Fuel, ammunition & stores: 212 tons, 12.2 %
Miscellaneous weights: 90 tons, 5.2 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
456 lbs / 207 Kg = 10.0 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 %): 51 %
- Recoil effect (Restricted arc if above 1.00): 0.47
Seaboat quality (Average = 1.00): 1.05

Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.400
Length to Beam Ratio: 11.36 : 1
'Natural speed' for length: 22.17 kts
Power going to wave formation at top speed: 64 %
Trim (Max stability = 0, Max steadiness = 100): 48
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: 22.00 ft / 6.71 m
- Forecastle (20 %): 21.00 ft / 6.40 m
- Mid (33 %): 12.00 ft / 3.66 m
- Quarterdeck (15 %): 12.00 ft / 3.66 m
- Stern: 12.00 ft / 3.66 m
- Average freeboard: 14.47 ft / 4.41 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 181.1 %
- Above water (accommodation/working, high = better): 96.5 %
Waterplane Area: 7,905 Square feet or 734 Square metres
Displacement factor (Displacement / loading): 66 %
Structure weight / hull surface area: 34 lbs/sq ft or 166 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 1.62
- Overall: 0.57
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is adequate

---
The RN also started Destroyer production again with an updated and enlarged V&W design to go in production along side the experimental X class. Unlike the X class, there is no room for growth and this is seen as the limit for a 1400ton ship. Future RN DD will be larger and more adaptable.

U Class, GB Destroyer laid down 1925

Displacement:
1,377 t light; 1,428 t standard; 1,580 t normal; 1,702 t full load

Dimensions: Length overall / water x beam x draught
360.00 ft / 360.00 ft x 32.00 ft x 12.00 ft (normal load)
109.73 m / 109.73 m x 9.75 m x 3.66 m

Armament:
4 - 4.50" / 114 mm guns in single mounts, 45.56lbs / 20.67kg shells, 1925 Model
Quick firing guns in deck mounts with hoists
on centreline ends, evenly spread, all raised mounts - superfiring
1 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1925 Model
Anti-aircraft gun in deck mount
on side amidships, 1 raised gun
4 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1925 Model
Machine guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 214 lbs / 97 kg
Shells per gun, main battery: 150
6 - 21.0" / 533.4 mm above water torpedoes

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.50" / 13 mm - -

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 37,990 shp / 28,341 Kw = 33.50 kts
Range 5,500nm at 12.00 kts (Bunkerage = 274 tons)

Complement:
124 - 162

Cost:
£0.625 million / $2.498 million

Distribution of weights at normal displacement:
Armament: 27 tons, 1.7 %
Armour: 5 tons, 0.3 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 5 tons, 0.3 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 858 tons, 54.3 %
Hull, fittings & equipment: 488 tons, 30.9 %
Fuel, ammunition & stores: 202 tons, 12.8 %
Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
396 lbs / 180 Kg = 8.7 x 4.5 " / 114 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.44
Metacentric height 1.7 ft / 0.5 m
Roll period: 10.3 seconds
Steadiness - As gun platform (Average = 50 %): 51 %
- Recoil effect (Restricted arc if above 1.00): 0.38
Seaboat quality (Average = 1.00): 1.08

Hull form characteristics:
Hull has raised forecastle, rise forward of midbreak
Block coefficient: 0.400
Length to Beam Ratio: 11.25 : 1
'Natural speed' for length: 18.97 kts
Power going to wave formation at top speed: 65 %
Trim (Max stability = 0, Max steadiness = 100): 47
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: 22.00 ft / 6.71 m
- Forecastle (20 %): 22.00 ft / 6.71 m (21.00 ft / 6.40 m aft of break)
- Mid (30 %): 21.00 ft / 6.40 m (11.00 ft / 3.35 m aft of break)
- Quarterdeck (15 %): 11.00 ft / 3.35 m
- Stern: 11.00 ft / 3.35 m
- Average freeboard: 14.20 ft / 4.33 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 188.2 %
- Above water (accommodation/working, high = better): 87.6 %
Waterplane Area: 7,091 Square feet or 659 Square metres
Displacement factor (Displacement / loading): 59 %
Structure weight / hull surface area: 33 lbs/sq ft or 163 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 1.74
- Overall: 0.57
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is cramped

Looks like only 3 or 2 raised guns on each ship to me, is there a reason they're all listed as raised mountings?

Also, the top views seem to show quadruple torpedo banks, where the SS design shows triple banks.

The 4" gun on the X class should be listed as centerline, not side mounted.

Nice pics.

The X class is an interesting design with the six single mounts - you should have a chat with Australia about that...

The U class is decent for its size, but I'm curious whether the lack of any miscellaneous weight implies no ASW capability...

So does this mean the 4.5" is going to be the standard British destroyer gun of this time?

Why is the 4.5"(4.45") calibre being used? The 4.7"(4.724") calibre is a better choice. Use the 40-cal Mk VIII. It has 90-degree elevation, powered rammers and RoF of 12rpm. The same as used for Nelson/Rodney. It worked, it had a long barrel life, a proper AA mount, and commonanilty with other British guns. There isn't much point in switching to the 4.5"(/45?) gun. It just makes logistics harder. The 4.5" used a fixed charge and shell and so had a combined weight of 87lb. Too heavy for prolonged firing. So they had to separate the charge and shell, nullifying any advantage of the smaller calibre. If more anti-surface punch is needed, then adopt a longer 4.7" gun, either the -45 cal of the V&W, or a new -50cal weapon. Or jump calibre and use the experimental 5.1"/50 gun that was tried.

I'm not sure of the usefulness of the 4" weapon. If switching to the 4.7"/40 with 90degree elevation, the need for this weapon is removed.

You want a mid-break to sim the raised forecastle. She currently is simmed as having a flush deck. You want 12ft in box 8, and 21ft in box 9 to sim this.

Quoted

Why is the 4.5"(4.45") calibre being used? The 4.7"(4.724") calibre is a better choice. Use the 40-cal Mk VIII. It has 90-degree elevation, powered rammers and RoF of 12rpm.

Basically, it's Gravina's choice of DD gun, which Alt_Naval is trying to honour. Personally, I prefer the 4.7" gun, but the 4.5" gun (I'm told) should make the logistics easier.

No, doesn't make much sense here, either. Sticking with the 'traditional' calibre seems more likely.

RLBH

Logistics are a tricky issue: if you don't change, you can use some older weapons and ammunition; but if you do, you can take more advantage of improvements in technology. With the Brits having a LOT of small ships that are due for replacement over the next decade, if there's a desire to make a change in bore size, it's a good time to get started with it. Either way is a valid choice.

True, but if you want a better performing gun, you use either the -50cal weapon, or move up to 62lb shell. Or skipping up to 4.5" guns.

Obviously these need some work. I just checked and Gravina had 4.7" twin AA on his g3 (as opposed to G3) so I guess that leans against a change. RLBH, pick either 4.5 or 4.7 and I'll fix these based on the comments so far. 4.7" is only on a handful of V&W. The RN tried a 5.1" on A-I class DD and found it too heavy for the size of the ships.

Cheers,

The 5.1"/50 experimental gun had a few problems. The most problematic was that it used a combined shell and charge making for a considerable weight. It was difficult to move around in the mount, and sustained rate of fire was low. Crew fatigue was another issue. For a heavier-hitting gun, it might have been a good idea with separate shell and charge, but it wouldn't have had much advantage over the 4.7"/50 with a 62lb shell.

I've taken the liberty of doing a redesign of both ships with the 4.7" gun, as I intend to use it.

X Class, Royal Navy Destroyer laid down 1926

Displacement:
1,545 t light; 1,611 t standard; 1,768 t normal; 1,893 t full load

Dimensions: Length overall / water x beam x draught
382.64 ft / 375.00 ft x 33.00 ft x 12.50 ft (normal load)
116.63 m / 114.30 m x 10.06 m x 3.81 m

Armament:
5 - 4.70" / 119 mm guns in single mounts, 62.00lbs / 28.12kg shells, 1926 Model
Quick firing guns in deck mounts with hoists
on centreline ends, majority forward, all raised mounts - superfiring
4 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1926 Model
Machine guns in deck mounts
on side, evenly spread
Weight of broadside 310 lbs / 141 kg
Shells per gun, main battery: 180
6 - 21.0" / 533.4 mm above water torpedoes

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.50" / 13 mm - -

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 35,953 shp / 26,821 Kw = 34.00 kts
Range 5,500nm at 12.00 kts
Bunker at max displacement = 281 tons

Complement:
136 - 177

Cost:
£0.709 million / $2.835 million

Distribution of weights at normal displacement:
Armament: 32 tons, 1.8 %
Armour: 7 tons, 0.4 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 7 tons, 0.4 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 884 tons, 50.0 %
Hull, fittings & equipment: 532 tons, 30.1 %
Fuel, ammunition & stores: 223 tons, 12.6 %
Miscellaneous weights: 90 tons, 5.1 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
431 lbs / 195 Kg = 8.3 x 4.7 " / 119 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.19
Metacentric height 1.3 ft / 0.4 m
Roll period: 12.1 seconds
Steadiness - As gun platform (Average = 50 %): 60 %
- Recoil effect (Restricted arc if above 1.00): 0.68
Seaboat quality (Average = 1.00): 1.00

Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0.400
Length to Beam Ratio: 11.36 : 1
'Natural speed' for length: 22.17 kts
Power going to wave formation at top speed: 64 %
Trim (Max stability = 0, Max steadiness = 100): 60
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: 21.00 ft / 6.40 m
- Forecastle (20 %): 20.00 ft / 6.10 m
- Mid (34 %): 20.00 ft / 6.10 m (11.00 ft / 3.35 m aft of break)
- Quarterdeck (15 %): 11.00 ft / 3.35 m
- Stern: 11.00 ft / 3.35 m
- Average freeboard: 14.14 ft / 4.31 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 181.5 %
- Above water (accommodation/working, high = better): 95.4 %
Waterplane Area: 7,905 Square feet or 734 Square metres
Displacement factor (Displacement / loading): 67 %
Structure weight / hull surface area: 35 lbs/sq ft or 169 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 1.52
- Overall: 0.55
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is adequate

----------------------------------------------------------------------------------------------------------

U Class, Royal Navy Destroyer laid down 1925

Displacement:
1,375 t light; 1,428 t standard; 1,580 t normal; 1,702 t full load

Dimensions: Length overall / water x beam x draught
368.37 ft / 360.00 ft x 32.00 ft x 12.00 ft (normal load)
112.28 m / 109.73 m x 9.75 m x 3.66 m

Armament:
4 - 4.70" / 119 mm guns in single mounts, 61.99lbs / 28.12kg shells, 1925 Model
Quick firing guns in deck mounts with hoists
on centreline ends, evenly spread, 3 raised mounts - superfiring
4 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1925 Model
Machine guns in deck mounts
on side, evenly spread
Weight of broadside 248 lbs / 113 kg
Shells per gun, main battery: 150
6 - 21.0" / 533.4 mm above water torpedoes

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.50" / 13 mm - -

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 37,990 shp / 28,341 Kw = 33.50 kts
Range 5,500nm at 12.00 kts
Bunker at max displacement = 274 tons

Complement:
124 - 162

Cost:
£0.621 million / $2.485 million

Distribution of weights at normal displacement:
Armament: 26 tons, 1.6 %
Armour: 5 tons, 0.3 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 5 tons, 0.3 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 856 tons, 54.2 %
Hull, fittings & equipment: 473 tons, 29.9 %
Fuel, ammunition & stores: 205 tons, 13.0 %
Miscellaneous weights: 15 tons, 0.9 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
362 lbs / 164 Kg = 7.0 x 4.7 " / 119 mm shells or 0.2 torpedoes
Stability (Unstable if below 1.00): 1.33
Metacentric height 1.5 ft / 0.5 m
Roll period: 10.9 seconds
Steadiness - As gun platform (Average = 50 %): 59 %
- Recoil effect (Restricted arc if above 1.00): 0.48
Seaboat quality (Average = 1.00): 1.01

Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0.400
Length to Beam Ratio: 11.25 : 1
'Natural speed' for length: 18.97 kts
Power going to wave formation at top speed: 65 %
Trim (Max stability = 0, Max steadiness = 100): 58
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: 23.00 ft / 7.01 m
- Forecastle (20 %): 21.00 ft / 6.40 m
- Mid (32 %): 20.00 ft / 6.10 m (10.00 ft / 3.05 m aft of break)
- Quarterdeck (15 %): 10.00 ft / 3.05 m
- Stern: 11.00 ft / 3.35 m
- Average freeboard: 13.70 ft / 4.17 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 188.6 %
- Above water (accommodation/working, high = better): 83.4 %
Waterplane Area: 7,091 Square feet or 659 Square metres
Displacement factor (Displacement / loading): 59 %
Structure weight / hull surface area: 33 lbs/sq ft or 163 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 1.55
- Overall: 0.56
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is cramped

On the X-class, why would all mounts be raised? Also, what would be the layout of the 3 forward mounts? Light on AA, but there's plenty of miscellaneous tonnage to improve this later as necessary.

On the U-class, why 3 raised mounts? AA mountings are light again, but this ship doesn't have a lot of growth room.

Layout is as per the pictures at the top of the page; I've no light AA as the 2pdr is probably rather extravagant on these ships. That said, the RN seems to have a 20mm gun that might be well suited to lighter craft.

I know the U-class is a dead end. It's a case of building something we know works whilst trying out the next generation (the X class).

RLBH

If the layout is as the pictures, I'd expect the X class to be set up with mounts on the centerline ends and another mount on the centerline midships, with 2 of the end mounts raise and the midships mount also raised. The U class would have only 2 raised mounts. The pictured X-class also has another gun mount of some sort (originally a 4" gun) on the centerline.

The 4" guns had to go when I went to 4.7" guns, unfortunately. But I've revised the sims with more AA and a better layout, although the X class now have a deck-level midships mount.

X Class, Royal Navy Destroyer laid down 1926

Displacement:
1,544 t light; 1,611 t standard; 1,768 t normal; 1,893 t full load

Dimensions: Length overall / water x beam x draught
382.64 ft / 375.00 ft x 33.00 ft x 12.50 ft (normal load)
116.63 m / 114.30 m x 10.06 m x 3.81 m

Armament:
4 - 4.70" / 119 mm guns in single mounts, 62.00lbs / 28.12kg shells, 1926 Model
Quick firing guns in deck mounts with hoists
on centreline ends, evenly spread, 2 raised mounts - superfiring
1 - 4.70" / 119 mm guns in single mounts, 62.00lbs / 28.12kg shells, 1926 Model
Quick firing gun in a deck mount with hoist
on centreline amidships
2 - 1.57" / 40.0 mm guns (1x2 guns), 2.01lbs / 0.91kg shells, 1926 Model
Anti-aircraft guns in deck mount
on centreline aft, all raised guns - superfiring
4 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1926 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
Weight of broadside 315 lbs / 143 kg
Shells per gun, main battery: 175
6 - 21.0" / 533.4 mm above water torpedoes

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.50" / 13 mm - -
2nd: 0.50" / 13 mm - -

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 35,953 shp / 26,821 Kw = 34.00 kts
Range 5,500nm at 12.00 kts
Bunker at max displacement = 281 tons

Complement:
136 - 177

Cost:
£0.710 million / $2.839 million

Distribution of weights at normal displacement:
Armament: 33 tons, 1.9 %
Armour: 7 tons, 0.4 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 7 tons, 0.4 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 883 tons, 50.0 %
Hull, fittings & equipment: 531 tons, 30.0 %
Fuel, ammunition & stores: 224 tons, 12.7 %
Miscellaneous weights: 90 tons, 5.1 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
437 lbs / 198 Kg = 8.4 x 4.7 " / 119 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.23
Metacentric height 1.4 ft / 0.4 m
Roll period: 11.8 seconds
Steadiness - As gun platform (Average = 50 %): 60 %
- Recoil effect (Restricted arc if above 1.00): 0.57
Seaboat quality (Average = 1.00): 1.02

Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0.400
Length to Beam Ratio: 11.36 : 1
'Natural speed' for length: 22.17 kts
Power going to wave formation at top speed: 64 %
Trim (Max stability = 0, Max steadiness = 100): 59
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: 21.00 ft / 6.40 m
- Forecastle (20 %): 20.00 ft / 6.10 m
- Mid (34 %): 20.00 ft / 6.10 m (11.00 ft / 3.35 m aft of break)
- Quarterdeck (15 %): 11.00 ft / 3.35 m
- Stern: 11.00 ft / 3.35 m
- Average freeboard: 14.14 ft / 4.31 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 181.7 %
- Above water (accommodation/working, high = better): 95.4 %
Waterplane Area: 7,905 Square feet or 734 Square metres
Displacement factor (Displacement / loading): 66 %
Structure weight / hull surface area: 35 lbs/sq ft or 169 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 1.55
- Overall: 0.56
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is adequate

---------------------------------------------------------------------------

U Class, Royal Navy Destroyer laid down 1925

Displacement:
1,375 t light; 1,428 t standard; 1,580 t normal; 1,702 t full load

Dimensions: Length overall / water x beam x draught
368.37 ft / 360.00 ft x 32.00 ft x 12.00 ft (normal load)
112.28 m / 109.73 m x 9.75 m x 3.66 m

Armament:
4 - 4.70" / 119 mm guns in single mounts, 62.00lbs / 28.12kg shells, 1925 Model
Quick firing guns in deck mounts with hoists
on centreline ends, evenly spread, 2 raised mounts - superfiring
2 - 1.57" / 40.0 mm guns (1x2 guns), 2.00lbs / 0.91kg shells, 1925 Model
Anti-aircraft guns in deck mount
on centreline amidships, all raised guns - superfiring
4 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1925 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
Weight of broadside 253 lbs / 115 kg
Shells per gun, main battery: 150
6 - 21.0" / 533.4 mm above water torpedoes

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.50" / 13 mm - -

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 37,990 shp / 28,341 Kw = 33.50 kts
Range 5,500nm at 12.00 kts
Bunker at max displacement = 274 tons

Complement:
124 - 162

Cost:
£0.622 million / $2.489 million

Distribution of weights at normal displacement:
Armament: 27 tons, 1.7 %
Armour: 5 tons, 0.3 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 5 tons, 0.3 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 855 tons, 54.1 %
Hull, fittings & equipment: 473 tons, 29.9 %
Fuel, ammunition & stores: 205 tons, 13.0 %
Miscellaneous weights: 15 tons, 0.9 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
364 lbs / 165 Kg = 7.0 x 4.7 " / 119 mm shells or 0.2 torpedoes
Stability (Unstable if below 1.00): 1.34
Metacentric height 1.5 ft / 0.5 m
Roll period: 10.9 seconds
Steadiness - As gun platform (Average = 50 %): 60 %
- Recoil effect (Restricted arc if above 1.00): 0.46
Seaboat quality (Average = 1.00): 1.02

Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0.400
Length to Beam Ratio: 11.25 : 1
'Natural speed' for length: 18.97 kts
Power going to wave formation at top speed: 65 %
Trim (Max stability = 0, Max steadiness = 100): 59
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: 23.00 ft / 7.01 m
- Forecastle (20 %): 21.00 ft / 6.40 m
- Mid (32 %): 20.00 ft / 6.10 m (10.00 ft / 3.05 m aft of break)
- Quarterdeck (15 %): 10.00 ft / 3.05 m
- Stern: 11.00 ft / 3.35 m
- Average freeboard: 13.70 ft / 4.17 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 188.7 %
- Above water (accommodation/working, high = better): 83.4 %
Waterplane Area: 7,091 Square feet or 659 Square metres
Displacement factor (Displacement / loading): 59 %
Structure weight / hull surface area: 33 lbs/sq ft or 163 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 1.57
- Overall: 0.56
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is cramped

X-class looks good now, the only remaining nit is on the U-class: you probably don't want the 40mm mount on the side, it should either be a centerline mount, like on the X-class, or single mounts on either side of the centerline.

Curses! Changed.

Looks good to me!