WesWorld

Right, this time two versions of the same vessel.

To make sure it all fits, I went against my tendencies and fiddled with pics of a couple USN destroyers, winding up with a vessel needing about 103m.



One as a pure escort, with the 1.0 hull.
Frankly, I'm still peeved that...despite our rules that ships going 24+ knots only need 0.5 to be adequate, folks were saying that 0.6 or 0.75 were still far to lightly built.

So that leads to the second question...gee, what can I get on the same darn hull, but if I call it a light destroyer not an escort and put the hull at 0.5?

Quoted

S52, Netherlands Escort laid down 1941

Displacement:
1,440 t light; 1,528 t standard; 1,745 t normal; 1,918 t full load

Dimensions: Length overall / water x beam x draught
350.22 ft / 337.93 ft x 37.73 ft x 11.98 ft (normal load)
106.75 m / 103.00 m x 11.50 m x 3.65 m

Armament:
4 - 4.92" / 125 mm guns (2x2 guns), 59.52lbs / 27.00kg shells, 1941 Model
Breech loading guns in deck mounts with hoists
on centreline ends, evenly spread
8 - 1.57" / 40.0 mm guns (2x4 guns), 1.94lbs / 0.88kg shells, 1941 Model
Breech loading guns in deck mounts
on centreline ends, evenly spread, all raised mounts
8 - 1.57" / 40.0 mm guns (2x4 guns), 1.94lbs / 0.88kg shells, 1941 Model
Breech loading guns in deck mounts
on side, all amidships, all raised mounts - superfiring
14 - 0.91" / 23.0 mm guns in single mounts, 0.44lbs / 0.20kg shells, 1941 Model
Breech loading guns in deck mounts
on side, evenly spread, 4 raised mounts
Weight of broadside 275 lbs / 125 kg
Shells per gun, main battery: 315
4 - 0.0" / 0 mm above water torpedoes

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.97" / 50 mm 2.95" / 75 mm 1.97" / 50 mm
2nd: 0.39" / 10 mm 0.83" / 21 mm -
3rd: 0.39" / 10 mm 0.83" / 21 mm -

Machinery:
Diesel Internal combustion generators,
Electric motors, 2 shafts, 17,126 shp / 12,776 Kw = 28.00 kts
Range 9,400nm at 12.00 kts
Bunker at max displacement = 390 tons

Complement:
134 - 175

Cost:
£0.882 million / $3.527 million

Distribution of weights at normal displacement:
Armament: 34 tons, 2.0 %
Armour: 43 tons, 2.5 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 43 tons, 2.5 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 453 tons, 25.9 %
Hull, fittings & equipment: 840 tons, 48.1 %
Fuel, ammunition & stores: 305 tons, 17.5 %
Miscellaneous weights: 70 tons, 4.0 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
2,196 lbs / 996 Kg = 36.8 x 4.9 " / 125 mm shells or 0.7 torpedoes
Stability (Unstable if below 1.00): 1.10
Metacentric height 1.4 ft / 0.4 m
Roll period: 13.4 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.34
Seaboat quality (Average = 1.00): 1.21

Hull form characteristics:
Hull has raised forecastle
and transom stern
Block coefficient: 0.400
Length to Beam Ratio: 8.96 : 1
'Natural speed' for length: 21.47 kts
Power going to wave formation at top speed: 60 %
Trim (Max stability = 0, Max steadiness = 100): 58
Bow angle (Positive = bow angles forward): 22.00 degrees
Stern overhang: 3.28 ft / 1.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 22.31 ft / 6.80 m
- Forecastle (20 %): 20.67 ft / 6.30 m (12.70 ft / 3.87 m aft of break)
- Mid (50 %): 12.70 ft / 3.87 m
- Quarterdeck (20 %): 12.70 ft / 3.87 m
- Stern: 14.34 ft / 4.37 m
- Average freeboard: 14.59 ft / 4.45 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 105.8 %
- Above water (accommodation/working, high = better): 147.0 %
Waterplane Area: 8,145 Square feet or 757 Square metres
Displacement factor (Displacement / loading): 135 %
Structure weight / hull surface area: 60 lbs/sq ft or 291 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.89
- Longitudinal: 2.76
- Overall: 1.00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Good seaboat, rides out heavy weather easily

Designed as a fast escort for a variety of duties, primarily convoy escort, but also can be pressed into other roles.
50mm of "Other' weight on 125mm is RPC gear. 21mm on 40mm mounts is tri-axle stabilization gear.

Quoted

Z90, Netherlands Light DD laid down 1941

Displacement:
1,600 t light; 1,696 t standard; 1,960 t normal; 2,171 t full load

Dimensions: Length overall / water x beam x draught
350.22 ft / 337.93 ft x 37.73 ft x 13.45 ft (normal load)
106.75 m / 103.00 m x 11.50 m x 4.10 m

Armament:
4 - 4.92" / 125 mm guns (2x2 guns), 59.52lbs / 27.00kg shells, 1941 Model
Breech loading guns in deck mounts with hoists
on centreline ends, evenly spread
8 - 1.57" / 40.0 mm guns (2x4 guns), 1.94lbs / 0.88kg shells, 1941 Model
Breech loading guns in deck mounts
on centreline ends, evenly spread, all raised mounts
8 - 1.57" / 40.0 mm guns (2x4 guns), 1.94lbs / 0.88kg shells, 1941 Model
Breech loading guns in deck mounts
on side, all amidships, all raised mounts - superfiring
14 - 0.91" / 23.0 mm guns in single mounts, 0.44lbs / 0.20kg shells, 1941 Model
Breech loading guns in deck mounts
on side, evenly spread, 4 raised mounts
Weight of broadside 275 lbs / 125 kg
Shells per gun, main battery: 340
4 - 0.0" / 0 mm above water torpedoes

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.97" / 50 mm 2.95" / 75 mm 1.97" / 50 mm
2nd: 0.39" / 10 mm 0.83" / 21 mm -
3rd: 0.39" / 10 mm 0.83" / 21 mm -

Machinery:
Diesel Internal combustion generators,
Electric motors, 2 shafts, 31,670 shp / 23,626 Kw = 32.00 kts
Range 6,500nm at 15.00 kts
Bunker at max displacement = 475 tons

Complement:
146 - 191

Cost:
£1.226 million / $4.903 million

Distribution of weights at normal displacement:
Armament: 34 tons, 1.8 %
Armour: 43 tons, 2.2 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 43 tons, 2.2 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 810 tons, 41.3 %
Hull, fittings & equipment: 637 tons, 32.5 %
Fuel, ammunition & stores: 360 tons, 18.4 %
Miscellaneous weights: 75 tons, 3.8 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
828 lbs / 376 Kg = 13.9 x 4.9 " / 125 mm shells or 0.4 torpedoes
Stability (Unstable if below 1.00): 1.19
Metacentric height 1.6 ft / 0.5 m
Roll period: 12.6 seconds
Steadiness - As gun platform (Average = 50 %): 71 %
- Recoil effect (Restricted arc if above 1.00): 0.41
Seaboat quality (Average = 1.00): 1.20

Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0.400
Length to Beam Ratio: 8.96 : 1
'Natural speed' for length: 21.47 kts
Power going to wave formation at top speed: 67 %
Trim (Max stability = 0, Max steadiness = 100): 59
Bow angle (Positive = bow angles forward): 22.00 degrees
Stern overhang: 3.28 ft / 1.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 22.31 ft / 6.80 m
- Forecastle (20 %): 20.67 ft / 6.30 m
- Mid (53 %): 20.67 ft / 6.30 m (12.70 ft / 3.87 m aft of break)
- Quarterdeck (20 %): 12.70 ft / 3.87 m
- Stern: 14.34 ft / 4.37 m
- Average freeboard: 17.22 ft / 5.25 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 153.2 %
- Above water (accommodation/working, high = better): 181.5 %
Waterplane Area: 8,145 Square feet or 757 Square metres
Displacement factor (Displacement / loading): 95 %
Structure weight / hull surface area: 39 lbs/sq ft or 189 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 2.99
- Overall: 0.60
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

Designed as a light destroyer for a mix of duties, from convoy to battle group escort.
Lacking in speed and armanent, they have the saving grace of being fairly cheap.
50mm of "Other' weight on 125mm is RPC gear.

I question the logic of a non-DP 5" gun in this timeframe.

I'm also unsure of how 'mm' refers to a weight measurement.

Quoted

Originally posted by ShinRa_Inc
I'm also unsure of how 'mm' refers to a weight measurement.

He means 50mm of the 75mm specified in the "other" armor on the 125mm guns. The actual armor would be 50mm face/25mm other (top/side)/50mm below deck (handling room/magazine). It works out to about 8t per mount.

Quoted

Originally posted by ShinRa_Inc
I question the logic of a non-DP 5" gun in this timeframe.

I'm also unsure of how 'mm' refers to a weight measurement.

drop down menu error.

And Sachmle's right.
Perhaps there is a better way to explain it. Alternately I had thought of going to "turret and barbette" on 125mm and "mount & hoist" on 40mm to "account" for RPC training gear. Not sure the best way to go about it, but I want the weight on the mount somehow rather than being in miscellaneous.

I like the 0.0" torpedos best. ;o)

Atlantean technology!

Quoted

despite our rules that ships going 24+ knots only need 0.5 to be adequate, folks were saying that 0.6 or 0.75 were still far to lightly built.

I'm not sure who these folks are, but the decision was made back then that for everything that goes faster than 24 knots the relative composite hull strength can go down as far as 0.50. When you look at the design rules, it is for "light fast combattants" and right behind that is given pretty much the definition of "light fast combattants": <6000 tons standard; >24kn. That S52 design is less than 6000 tons and is faster than 24 knots so no matter what those folks say and how unrealistic it might turn out to be, you are allowed to go down to 0.5 cross-sectional hull strength with that design.

Quoted

Originally posted by Rooijen10
That S52 design is less than 6000 tons and is faster than 24 knots so no matter what those folks say and how unrealistic it might turn out to be, you are allowed to go down to 0.5 cross-sectional hull strength with that design.

However such a design will be unrealistic for the real-world. Having a more strongly built ship that can pull alongside other ships underway without suffering damage is quite valuable, as is the additional weather protection and longer lifetime of the hulls. However these don't get factored into SS.

Personally I think the topweight is the largest issue for these sorts of ships. Removing engine mass doesn't make the stability characteristics so much better in order to add in lots of AAA and radars high up in the ship.

Quoted

Originally posted by HoOmAn
I like the 0.0" torpedos best. ;o)

D'oh.
Supposed to be 4x24" Torps, and DP 125mm guns.
The 40mm and 23mm aren't breechloaders either. Making those changes seems to not effect anything.

Oh and I should point out the hulls do differ slightly in draft, but not in deckspace. Which is much of the light tonnage difference.

Anyone have any better ideas on how to model RPC? At this point it's an 'in progress' tech, but by time these are completed, there should be an in-service mount.

Any comments about one being better/worse than the other? Viability of concept? Lack of armor

In regards to Red Admiral's comments :

As for hull strength, the issue is that lightweight engines weigh to much and allowing to go to 0.5 is to allow for that.

Generally speaking, ages ago while browsing books, I noted that weight in framing tended to be around the ships main gun size- battleships ran 12-15%+, while DDs were in the 4-5% range. The observation may or may not be correct, but overall, DDs are lighter built, which again the 0.5 reflects.

As for lifetime of the hulls, the Vs & Ws served from just after WWI to just after WWII. That's not bad.

The Gearings lasted in USN service- with refurbishment- from WWII until the 1970s, and some were then sold, with the Chinese ones retiring in the 2000s. Half a century is not bad.

The Sumners not only served in the war, but also continued into the 1970s, and then were transfered.

For escorts, I expect them to spend most of their time in reserve- being pulled out for such things as Red Sea Convoys I & II, SAE convoys, SEA convoys, etc.

So I'm really not seeing why the escorts would need double the hull strength of the comparable destroyer, if the destroyer can last 30-50 years.

Quoted

Anyone have any better ideas on how to model RPC? At this point it's an 'in progress' tech, but by time these are completed, there should be an in-service mount.

For the acronym-challenged among us, what is "RPC"?

"RPC? Are you sure, sir? Do your vessels really need a Reformed Presbyterian Church aboard??"

Quoted

Originally posted by BruceDuncan
For the acronym-challenged among us, what is "RPC"?

Remote power control, where the AA suite is slaved to the Fire control center instead of each being fed information and performing their own inputs/training.

Quoted

Originally posted by Kaiser Kirk

Quoted

Originally posted by BruceDuncan
For the acronym-challenged among us, what is "RPC"?

Remote power control, where the AA suite is slaved to the Fire control center instead of each being fed information and performing their own inputs/training.

Ah. Thank you.