Ultra-light Destroyer

Intermediate

Thursday, February 7th 2008, 7:34am

Ok, first off, I know she has only about 9 hours worth of endurance at 31 knots. As she's intended as a coast defense torpedo boat, I think she's got enough fuel to do her job. I looked at a radius of action, and 4 squadrons would be able to cover the Polish coast nicely, if I could afford another port at Ustka.

Now, that being said, her primary design requirements were :
1.) fit into the smallest dry dock I have.
2.) make as scant a use of resources as possible.
3.) be as cheap to produce in large numbers as possible.

Her weapons are the old Austrian 2.75" QF and the IJN's Hotchkiss 25mm clone which are becoming my small craft weapons of choice in N-verse. They probably didn't age too well... but hey, Poland isn't on the cutting edge of tech.

Or is it?

Source code

Torpedowce laid down 1935

Displacement:
	475 t light; 494 t standard; 549 t normal; 593 t full load

Dimensions: Length overall / water x beam x draught
	230.00 ft / 230.00 ft x 20.00 ft x 10.25 ft (normal load)
	70.10 m / 70.10 m x 6.10 m  x 3.12 m

Armament:
      4 - 2.75" / 69.9 mm guns (2x2 guns), 10.00lbs / 4.54kg shells, 1935 Model
	  Dual purpose guns in deck mounts 
	  on centreline ends, evenly spread, 1 raised mount aft - superfiring
      6 - 1.00" / 25.4 mm guns (2x3 guns), 0.50lbs / 0.23kg shells, 1935 Model
	  Anti-aircraft guns in deck mounts 
	  on side, all amidships, all raised mounts - superfiring
	Weight of broadside 43 lbs / 20 kg
	Shells per gun, main battery: 300
	3 - 20.0" / 508 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, 
	Direct drive, 2 shafts, 18,000 shp / 13,428 Kw = 30.91 kts
	Range 2,400nm at 14.91 kts
	Range 280nm at 30.91 kts
	Bunker at max displacement = 99 tons

Complement:
	56 - 73

Cost:
	£0.310 million / $1.239 million

Distribution of weights at normal displacement:
	Armament: 6 tons, 1.0 %
	Armour: 3 tons, 0.5 %
	   - Belts: 0 tons, 0.0 %
	   - Torpedo bulkhead: 0 tons, 0.0 %
	   - Armament: 3 tons, 0.5 %
	   - Armour Deck: 0 tons, 0.0 %
	   - Conning Tower: 0 tons, 0.0 %
	Machinery: 282 tons, 51.4 %
	Hull, fittings & equipment: 176 tons, 32.1 %
	Fuel, ammunition & stores: 74 tons, 13.4 %
	Miscellaneous weights: 9 tons, 1.6 %

Overall survivability and seakeeping ability:
	Survivability (Non-critical penetrating hits needed to sink ship):
	  149 lbs / 67 Kg = 14.3 x 2.8 " / 70 mm shells or 0.2 torpedoes
	Stability (Unstable if below 1.00): 1.20
	Metacentric height 0.6 ft / 0.2 m
	Roll period: 10.6 seconds
	Steadiness	- As gun platform (Average = 50 %): 51 %
			- Recoil effect (Restricted arc if above 1.00): 0.20
	Seaboat quality  (Average = 1.00): 1.00

Hull form characteristics:
	Hull has rise forward of midbreak
	Block coefficient: 0.408
	Length to Beam Ratio: 11.50 : 1
	'Natural speed' for length: 15.17 kts
	Power going to wave formation at top speed: 71 %
	Trim (Max stability = 0, Max steadiness = 100): 51
	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:		19.00 ft / 5.79 m
	   - Forecastle (15 %):	16.00 ft / 4.88 m
	   - Mid (35 %):		16.00 ft / 4.88 m (8.00 ft / 2.44 m aft of break)
	   - Quarterdeck (10 %):	8.00 ft / 2.44 m
	   - Stern:		9.00 ft / 2.74 m
	   - Average freeboard:	11.03 ft / 3.36 m

Ship space, strength and comments:
	Space	- Hull below water (magazines/engines, low = better): 176.3 %
		- Above water (accommodation/working, high = better): 58.1 %
	Waterplane Area: 2,844 Square feet or 264 Square metres
	Displacement factor (Displacement / loading): 51 %
	Structure weight / hull surface area: 23 lbs/sq ft or 112 Kg/sq metre
	Hull strength (Relative):
		- Cross-sectional: 0.50
		- Longitudinal: 4.15
		- Overall: 0.61
	Hull space for machinery, storage, compartmentation is cramped
	Room for accommodation and workspaces is cramped

Go to the top of the page

HoOmAn

Keeper of the Sacred Block Coefficient

Posts: 7,417

2

Thursday, February 7th 2008, 9:39am

Hi!

Isn´t 300 shells per man gun a bit excessive for a vessel not meant and build to run long operations?

Her l:b ratio of 11,5:1 is very, very high and sounds like she`ll go *snap* right in the middle once she hits a bigger wave first time....

Go to the top of the page

Tanthalas

Intermediate

Posts: 352

3

Thursday, February 7th 2008, 9:45am

Quoted

Originally posted by HoOmAn
Hi!

Isn´t 300 shells per man gun a bit excessive for a vessel not meant and build to run long operations?

Her l:b ratio of 11,5:1 is very, very high and sounds like she`ll go *snap* right in the middle once she hits a bigger wave first time....

its a Carthaginian thing, when I clicked this link I was afraid it was going to be one of his 250 toners that swarm all around the gulf of mexico in the Nverse, me i like nice healthy 1000 toners

Go to the top of the page

Hrolf Hakonson

Scooby-Doo

Posts: 6,178

4

Thursday, February 7th 2008, 12:05pm

70mm guns are really too small for use as main guns on anything that's intended to engage destroyers, that was true as far back as the Great War (when the German HSF started upgunning it's TBs to at least 88mm and better to 105mm). So far, Poland has seemed to settle on the Nordish 110mm gun as it's standard DD weapon, along with 600mm torpedoes in fair quantities. If Poland were looking to something smaller than around 1000 tons, it might be better served with MTBs.

Go to the top of the page

Carthaginian

Intermediate

Posts: 241

5

Thursday, February 7th 2008, 6:49pm

HoOmAn,

Radius of operation from shore is only about 130 miles.In the Baltic, that's a pretty fair piece; I'd hoped to get a 200 n. mi. range at max speed out of her, but alas, not to be on a 6 month construction run.

As-is, she's good for virtually the entire Polish coast with the condition I mentioned.

The 300 rpg was in case the ship was needed to do AA work for any larger ships she might be escorting; I figure the Baltic is small enough that aircraft will be a constant- and possibly the greatest- threat to surface ships. This was the rationale for the small gun with a lot of shells- something that would make for an adequate AA defense, but still be able to kill MTB's wasily enough. I'll try simming with something larger and see how that works out. What would be appropriate gun caliber and rpg figures in your opinion?

Also, her L:B is within WW's rule limits, and her small size would make her pretty tough; 0.61 is 22% greater than the minimum figure for small craft, and as the ship won't be leaving the Baltic, I'd think it would be sufficient... of course, I'm used to considering the Gulf of Mexico in my designs, which runs 6'-10' seas as 'normal', when I figure necessary strength for a design. About what kind of conditions would I expect from the Baltic, and how overbuilt would a ship need to be in comparison?

Hrolf Hakonson,

She's not really meant to take on destroyers. The guns are primarily considered AA and anti-TB weapons. In the event of destroyers coming within their operating radius, their best course of action would be to run for home and the cover of friendly shore batteries.

As for the choice of 70mm... well, I'm designing pre-WWI ships ATM in N-verse, and I stuck with a caliber I'm using already. I figured that a 10-pound flack shell would be enough to discourage aircraft, and thier common would also be sufficient to kill any MTB's that might attack the formation. Their high ROF would partially compensate for the small shell size in these roles, and the lighter weight of the guns/mount would make them easier to aim. Also, I used my standard 20" torp because that's what I'm used to using. I can design with a 600mm as far as that goes.

How would I sim MTB's? SInce we haven't gotten that far in N-verse, I have no experience in doing this... but I figured that ships of this 'in-between' size might have better luck in the Baltic.

Go to the top of the page

AdmKuznetsov

Sage

Posts: 2,918

6

Thursday, February 7th 2008, 7:35pm

Some good thinking here

Quoted

I figure the Baltic is small enough that aircraft will be a constant- and possibly the greatest- threat to surface ships.

Aircraft will be a bit threat. Probably a bigger one will be mines, which near the coasts of Russia and her allies, will be so dense you'd be able to walk through the minefields if they were to surface

Naval operations on the Baltic will be greatly restricted, by the narrow sea, strike aircraft buzzing like a swarm of hornets above the surface, and mines thick as fleas on a bear below the surface. The VMF has gotten everything bigger than a Light Cruiser out of there, and are downright gleeful that the Poles are wasting money and steel on a battlecruiser

Go to the top of the page

Carthaginian

Intermediate

Posts: 241

7

Thursday, February 7th 2008, 7:52pm

Ok, here's a larger version of the design, geared toward fixing the suggested gun problems.
To let you guys know what I'm shooting for, I'm thinking about something on the order of the turbine-powered TB's that the Baltic States used pre-WWII. Here's a generic example, a boat form Denmark laid down contemporary to the sim:
http://www.warshipsww2.eu/lode.php?langu…od=&idtrida=392
Now, unfortunately, I can't exactly sim THAT in SS; no way to get all that on a 60m, 300t hull and trick SS into thinking that she'll stay seaworthy on anything rougher than the Mississippi on a calm day... if I can trick SS into thinking that her keel wouldn't snap from her own weight while sitting by the dock.

Of course, such ships are going to be small and pretty weak-hulled compared to a real destroyer, but they weren't really meant to go up against a real DD either. Any German Zerstörere worth her salt would have cut through a ship like this in a heartbeat... but 10 of them coming out of the mist would have given the CO of Tirpitz a mild heart attack. Most of the CDS's that seem to be in vogue in WW at this point in time would have real cause to worry if faced with an equivalent tonnage of these little ships in confined waters.

That's the reason for building these:
1.) economy - more can be produced than larger destroyer designs
2.) utility - more useful than MTB's against other small craft
3.) range - longer-ranged than small MTB's, allowing for true patrols
Since I'm in confined waters and have a pretty small coastline to defend, I'm thinking a small DD under 750t would do the job. Yes, bigger ships look pretty and are nice for blue-water navies, but Poland sits at a point where ships can be small and their range can be short, yet they can still have major strategic value.

Anyway, here's the larger design... total build time is 9.5 months. Not sure how pricing runs here, but it's pretty cheap to build. These can cover the entire width of the Baltic (at the Polish coast) at top speed and two 10-boat squadrons would be able to cover the entire Polish coast with relative ease with plenty of overlap for cooperative operations. Though they aren't any good for a nation conducting open-sea warfare, they seem well-suited to their intended jobs:
1.) Coastal patrol and defense
2.) AA escort for local ops

Source code

T-01, Poland Torpedowce laid down 1935

Displacement:
	525 t light; 546 t standard; 646 t normal; 726 t full load

Dimensions: Length overall / water x beam x draught
	229.66 ft / 229.66 ft x 22.97 ft x 10.50 ft (normal load)
	70.00 m / 70.00 m x 7.00 m  x 3.20 m

Armament:
      3 - 3.46" / 88.0 mm guns in single mounts, 22.05lbs / 10.00kg shells, 1935 Model
	  Dual purpose guns in deck mounts 
	  on centreline, evenly spread
	  Aft Main mounts separated by engine room
      6 - 0.98" / 25.0 mm guns (2x3 guns), 0.55lbs / 0.25kg shells, 1935 Model
	  Anti-aircraft guns in deck mounts 
	  on side, all forward
      3 - 0.98" / 25.0 mm guns (1x3 guns), 0.55lbs / 0.25kg shells, 1935 Model
	  Anti-aircraft guns in deck mount 
	  on centreline aft, all raised guns - superfiring
	Weight of broadside 71 lbs / 32 kg
	Shells per gun, main battery: 200
	3 - 23.6" / 600 mm above water torpedoes

Armour:
   - Gun armour:	Face (max)	Other gunhouse (avg)	Barbette/hoist (max)
	Main:	0.98" / 25 mm	      -			      -
	2nd:	0.51" / 13 mm	      -			      -
	3rd:	0.51" / 13 mm	      -			      -

Machinery:
	Oil fired boilers, steam turbines, 
	Direct drive, 2 shafts, 18,000 shp / 13,428 Kw = 30.01 kts
	Range 3,800nm at 15.28 kts
	Range 470nm at 30.01 kts
	Bunker at max displacement = 180 tons

Complement:
	63 - 83

Cost:
	£0.358 million / $1.430 million

Distribution of weights at normal displacement:
	Armament: 8 tons, 1.3 %
	Armour: 6 tons, 0.9 %
	   - Belts: 0 tons, 0.0 %
	   - Torpedo bulkhead: 0 tons, 0.0 %
	   - Armament: 6 tons, 0.9 %
	   - Armour Deck: 0 tons, 0.0 %
	   - Conning Tower: 0 tons, 0.0 %
	Machinery: 321 tons, 49.6 %
	Hull, fittings & equipment: 181 tons, 28.0 %
	Fuel, ammunition & stores: 121 tons, 18.8 %
	Miscellaneous weights: 9 tons, 1.4 %
		3 x 600mm torps & launchers, no reloads

Overall survivability and seakeeping ability:
	Survivability (Non-critical penetrating hits needed to sink ship):
	  180 lbs / 82 Kg = 8.7 x 3.5 " / 88 mm shells or 0.2 torpedoes
	Stability (Unstable if below 1.00): 1.27
	Metacentric height 0.8 ft / 0.3 m
	Roll period: 10.5 seconds
	Steadiness	- As gun platform (Average = 50 %): 50 %
			- Recoil effect (Restricted arc if above 1.00): 0.17
	Seaboat quality  (Average = 1.00): 0.85

Hull form characteristics:
	Hull has rise forward of midbreak
	Block coefficient: 0.408
	Length to Beam Ratio: 10.00 : 1
	'Natural speed' for length: 15.15 kts
	Power going to wave formation at top speed: 71 %
	Trim (Max stability = 0, Max steadiness = 100): 59
	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:		18.86 ft / 5.75 m
	   - Forecastle (15 %):	15.58 ft / 4.75 m
	   - Mid (36 %):		14.76 ft / 4.50 m (8.20 ft / 2.50 m aft of break)
	   - Quarterdeck (10 %):	8.20 ft / 2.50 m
	   - Stern:		8.20 ft / 2.50 m
	   - Average freeboard:	10.97 ft / 3.34 m

Ship space, strength and comments:
	Space	- Hull below water (magazines/engines, low = better): 172.2 %
		- Above water (accommodation/working, high = better): 50.5 %
	Waterplane Area: 3,263 Square feet or 303 Square metres
	Displacement factor (Displacement / loading): 58 %
	Structure weight / hull surface area: 24 lbs/sq ft or 118 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 cramped
	Poor seaboat, wet and uncomfortable, reduced performance in heavy weather

This post has been edited 1 times, last edit by "Carthaginian" (Feb 7th 2008, 7:57pm)

Go to the top of the page

Carthaginian

Intermediate

Posts: 241

8

Thursday, February 7th 2008, 7:56pm

RE: Some good thinking here

Quoted

Originally posted by AdmKuznetsov
The VMF has gotten everything bigger than a Light Cruiser out of there, and are downright gleeful that the Poles are wasting money and steel on a battlecruiser

Oh, should I get Poland, that waste of steel would be turned into razorblades and recycled into something useful... like these little ships and aircraft to fight my enemies.

Big ships are for big oceans.
They don't belong on the Baltic.

Go to the top of the page

Vukovlad

Me too !!!

Posts: 4,137

9

Thursday, February 7th 2008, 7:58pm

Or sell it to Persia for a reasonable price

Go to the top of the page

Carthaginian

Intermediate

Posts: 241

10

Thursday, February 7th 2008, 8:05pm

Quoted

Originally posted by Vukovlad
Or sell it to Persia for a reasonable price

Start talkin'... it's your nickel.

If I get Poland, I'd be MORE than interested in getting rid of such a useless addition to my fleet. Persia would be welcome to purchase the ship.

BTW, exactly where is this ship being built, and how far along is it?

Go to the top of the page

Vukovlad

Me too !!!

Posts: 4,137

11

Thursday, February 7th 2008, 8:11pm

Good question, I cant see it being built in Nordmark...

Any way send an offer (PM) and let the haggling begin

Go to the top of the page

AdmKuznetsov

Sage

Posts: 2,918

12

Thursday, February 7th 2008, 8:13pm

No! Wait!

Quoted

Oh, should I get Poland, that waste of steel would be turned into razorblades and recycled into something useful... like these little ships and aircraft to fight my enemies.

Ummmm...., No! That would be a terrible mistake! She'll be the biggest ship target on the Baltic! She'll rule the sea! Appeal to Polish vanity/superiority complex vis-a-vis Russia... And look, she's far more powerful than anything the Russians have on the Baltic! Their little ships will all run in terror from her! dropping more mines as they go, praying for pursuit...

According to Poland's Q3/35 report, she's at the Type 3 drydock at Koszalin, and has 18,472 tons remaining out of 25,694.

So she's not far along at all, only 28% built.

This post has been edited 3 times, last edit by "AdmKuznetsov" (Feb 7th 2008, 8:18pm)

Go to the top of the page

Hrolf Hakonson

Scooby-Doo

Posts: 6,178

13

Thursday, February 7th 2008, 8:17pm

Quoted

Originally posted by Carthaginian

Quoted

Originally posted by Vukovlad
Or sell it to Persia for a reasonable price

Start talkin'... it's your nickel.
If I get Poland, I'd be MORE than interested in getting rid of such a useless addition to my fleet. Persia would be welcome to purchase the ship.

BTW, exactly where is this ship being built, and how far along is it?

From Poland's Q3 report:

at Koszalin
1 Type 3 drydock BC Warsaw laid down February 01 35, 3000t used (18472t to complete)

So she's being built in Poland, and has almost 1/3 of her steel delivered and made up (it's not all installed yet, but the materials have been paid for).

Go to the top of the page

Brockpaine

The Shadow

Posts: 15,109

14

Thursday, February 7th 2008, 8:18pm

Probably being built in Gdyna. It says laid down in 1935, and according to the infrastructure rules build time will be Light tonnage / 1000 + 9 months. So...

(25,694/1000) + 9 = 34.694 months

Presuming construction started in Q1 of 1935 (I am uncertain if it did or not) then you're looking at completion in November of 1937, followed by a six-month breaking in period.

Quoted

A ship may be launched when materials totalling 40% of its light displacement have been installed or when it is 40% through its theoretical building time, whichever is the later date.

A ship is completed when materials totalling 100% of its light displacement have been installed or when it is 100% through its theoretical building time, whichever is the later date.

So Warszawa should be launched in early to mid 1936 (or whenever 40% of materials are put on her) and should complete no earlier than November 1937. (Presuming that she was laid down in Q1 1935.)

EDIT: Ah, nvm, folks more knowledgeable than me answered first!

This post has been edited 1 times, last edit by "Brockpaine" (Feb 7th 2008, 8:19pm)

Go to the top of the page

Tanthalas

Intermediate

Posts: 352

15

Thursday, February 7th 2008, 8:19pm

doph she is up to the finish her or convert her stage then...

Go to the top of the page

Carthaginian

Intermediate

Posts: 241

16

Thursday, February 7th 2008, 8:23pm

Hmmm...
What would my losses be if she was broken up at this phase? Would the 'delivered, but not installed' steel be considered 'lost?' Or could I re-route it to other concerns?

Anyway, that white elephant's gotta go.
One way or another.

Go to the top of the page

Brockpaine

The Shadow

Posts: 15,109

17

Thursday, February 7th 2008, 8:26pm

Turn her into a carrier. Probably could sell her to Brazil or something.

Go to the top of the page

Hrolf Hakonson

Scooby-Doo

Posts: 6,178

18

Thursday, February 7th 2008, 8:27pm

On the small torpedo boats, I'd be a bit concerned about the relatively low top speed. As noted already, the most likely "playmates" for such a vessel in the Baltic are going to be MTBs, destroyers, and maybe light cruisers, most of which are pretty quick. A top speed of 30 knots might not get the job done. Also, for a 1935 design, you should replace the direct-drive turbines with geared models.

A 70mm gun will throw a shell that will, on a direct hit, kill any plane (as already noted in some Polish designs that use a 70mm gun, see the Polish destroyer entries). The problem is going to be that the amount of explosive fitted into the shell won't be enough to provide much of any kill radius when fitted with time fuzes.

As far as MTBs go, we haven't been trying to design those using SS, more using historical types (Germany's just sold several copies of the historical S-boat 1937 design, with minor cannon modifications, to Persia).