WesWorld

A class of 15 units laid down in 1922. Because of the treaty many of the older destroyers (and many not so old) had to be scrapped, thus the Admiralty has decided to lay down some series of light units in the 600t limit until the needs of the RN are fullfilled.

This is the first series, a TB, to be followed in the next years by others of "second class" DDs.



1922 TB, British Torpedo Boat laid down 1922

Displacement:
582 t light; 600 t standard; 687 t normal; 754 t full load

Dimensions: Length overall / water x beam x draught
255,89 ft / 250,00 ft x 25,45 ft x 9,00 ft (normal load)
78,00 m / 76,20 m x 7,76 m x 2,74 m

Armament:
2 - 4,00" / 102 mm guns in single mounts, 32,00lbs / 14,51kg shells, 1922 Model
Breech loading guns in deck mounts
on centreline ends, evenly spread
4 - 1,57" / 40,0 mm guns (1x4 guns), 1,95lbs / 0,88kg shells, 1922 Model
Anti-aircraft guns in deck mount
on side amidships
2 - 0,79" / 20,0 mm guns in single mounts, 0,24lbs / 0,11kg shells, 1922 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
Weight of broadside 72 lbs / 33 kg
Shells per gun, main battery: 100
3 - 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:
Diesel Internal combustion motors,
Geared drive, 2 shafts, 23.755 shp / 17.721 Kw = 32,00 kts
Range 1.830nm at 18,00 kts (Bunkerage = 157 tons)

Complement:
66 - 87

Cost:
£0,218 million / $0,872 million

Distribution of weights at normal displacement:
Armament: 9 tons, 1,3 %
Armour: 3 tons, 0,4 %
- Belts: 0 tons, 0,0 %
- Torpedo bulkhead: 0 tons, 0,0 %
- Armament: 3 tons, 0,4 %
- Armour Deck: 0 tons, 0,0 %
- Conning Tower: 0 tons, 0,0 %
Machinery: 371 tons, 54,1 %
Hull, fittings & equipment: 199 tons, 28,9 %
Fuel, ammunition & stores: 106 tons, 15,4 %
Miscellaneous weights: 0 tons, 0,0 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
163 lbs / 74 Kg = 5,1 x 4,0 " / 102 mm shells or 0,2 torpedoes
Stability (Unstable if below 1.00): 1,44
Metacentric height 1,2 ft / 0,4 m
Steadiness - As gun platform (Average = 50 %): 52 %
- Recoil effect (Restricted arc if above 1.00): 0,12
Seaboat quality (Average = 1.00): 1,04

Hull form characteristics:
Hull has raised forecastle
Block coefficient: 0,420
Length to Beam Ratio: 9,82 : 1
'Natural speed' for length: 15,81 kts
Power going to wave formation at top speed: 73 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 15,00 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 (30 %): 20,00 ft / 6,10 m (11,00 ft / 3,35 m aft of break)
- Mid (50 %): 11,00 ft / 3,35 m
- Quarterdeck (15 %): 10,00 ft / 3,05 m
- Stern: 10,00 ft / 3,05 m
- Average freeboard: 13,62 ft / 4,15 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 184,3 %
- Above water (accommodation/working, high = better): 78,3 %
Waterplane Area: 3.761 Square feet or 349 Square metres
Displacement factor (Displacement / loading): 41 %
Structure weight / hull surface area: 21 lbs/sq ft or 103 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0,40
- Longitudinal: 3,74
- Overall: 0,50
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is cramped

Quoted

4 - 1,57" / 40,0 mm guns (1x4 guns), 1,95lbs / 0,88kg shells, 1922 Model
Anti-aircraft guns in deck mount
on side amidships

Wouldn't this work better as 'on centerline, aft, raised mount - superfiring'?

Nice little boat - except the cross-sectional hull strength is under .50, that'll cause trouble...

Quoted

Wouldn't this work better as 'on centerline, aft, raised mount - superfiring'?

I´ll work it out, though I don´t think it will make much a difference...

Quoted

Nice little boat - except the cross-sectional hull strength is under .50, that'll cause trouble...

I guess we could allways say that these ships are intended as coastal vessels, not oceangoing... I´ll try to modify the design anyway.

Awww she is sooo cute!

But how do they get around without propellers ; )

Cheers,

Thats what the warp drive is for, those life boats are cleverly disguised warp engine nacelles!

Well she's make .5 past lightspeed...warp 1.5 that is.

Nice little ship. And the speed makes her a threat.

As mentioned before her cross-sec hs should be 0,5+ but otherwise she´s a nice little ship. Propably inferior to the RSANs light DDs as your design is lacking misc weight for depth charges, carries less TTs and main guns. Okay, she´s a little bit faster but I doubt that will make a difference in service. One also has to note that the LD23-design is 4% heavier but build to the cross-sec hs strength limit of 0,5...

Cheers,

HoOmAn

I guess now I´ve to call the class after HMS Defiant or HMS Millenum Falcon... hmmmmm... Photon torpedoes....

There she is corrected, a bit slower, but up to all the limits, and some minor nitpicks corrected. And Hooman, perhaps your DDs are superior, but this ship is not a DD, not event a second class one, It´s just an old style torpedo boat. Perhaps another series later could have improved AA and torpedo weaponry, but time will tell.



1922 TB, British Torpedo Boat laid down 1922

Displacement:
583 t light; 600 t standard; 650 t normal; 687 t full load

Dimensions: Length overall / water x beam x draught
254,82 ft / 250,00 ft x 25,00 ft x 9,10 ft (normal load)
77,67 m / 76,20 m x 7,62 m x 2,77 m

Armament:
2 - 4,00" / 102 mm guns in single mounts, 32,00lbs / 14,51kg shells, 1922 Model
Breech loading guns in deck mounts
on centreline ends, evenly spread
4 - 1,57" / 40,0 mm guns (1x4 guns), 1,95lbs / 0,88kg shells, 1922 Model
Anti-aircraft guns in deck mount
on centreline aft, all raised guns - superfiring
2 - 0,79" / 20,0 mm guns in single mounts, 0,24lbs / 0,11kg shells, 1922 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
Weight of broadside 72 lbs / 33 kg
Shells per gun, main battery: 100
3 - 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, 20.996 shp / 15.663 Kw = 31,50 kts
Range 1.440nm at 16,00 kts (Bunkerage = 89 tons)

Complement:
63 - 83

Cost:
£0,208 million / $0,831 million

Distribution of weights at normal displacement:
Armament: 9 tons, 1,4 %
Armour: 3 tons, 0,4 %
- Belts: 0 tons, 0,0 %
- Torpedo bulkhead: 0 tons, 0,0 %
- Armament: 3 tons, 0,4 %
- Armour Deck: 0 tons, 0,0 %
- Conning Tower: 0 tons, 0,0 %
Machinery: 344 tons, 53,0 %
Hull, fittings & equipment: 227 tons, 35,0 %
Fuel, ammunition & stores: 67 tons, 10,3 %
Miscellaneous weights: 0 tons, 0,0 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
182 lbs / 83 Kg = 5,7 x 4,0 " / 102 mm shells or 0,2 torpedoes
Stability (Unstable if below 1.00): 1,32
Metacentric height 1,0 ft / 0,3 m
Steadiness - As gun platform (Average = 50 %): 53 %
- Recoil effect (Restricted arc if above 1.00): 0,14
Seaboat quality (Average = 1.00): 1,05

Hull form characteristics:
Hull has raised forecastle
Block coefficient: 0,400
Length to Beam Ratio: 10,00 : 1
'Natural speed' for length: 15,81 kts
Power going to wave formation at top speed: 71 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 15,00 degrees
Stern overhang: 0,00 ft / 0,00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 18,00 ft / 5,49 m
- Forecastle (40 %): 18,00 ft / 5,49 m (10,00 ft / 3,05 m aft of break)
- Mid (50 %): 10,00 ft / 3,05 m
- Quarterdeck (15 %): 10,00 ft / 3,05 m
- Stern: 8,00 ft / 2,44 m
- Average freeboard: 13,05 ft / 3,98 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 181,3 %
- Above water (accommodation/working, high = better): 73,6 %
Waterplane Area: 3.638 Square feet or 338 Square metres
Displacement factor (Displacement / loading): 43 %
Structure weight / hull surface area: 25 lbs/sq ft or 123 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0,50
- Longitudinal: 4,14
- Overall: 0,62
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is cramped

Quoted

Originally posted by Gravina
And Hooman, perhaps your DDs are superior, but this ship is not a DD, not event a second class one, It´s just an old style torpedo boat. Perhaps another series later could have improved AA and torpedo weaponry, but time will tell.

I´m also not calling my 600ts vessels DDs. They surely can´t do what a real DD can do. They´re more along the lines of an DE (destroyer escort) - but I don´t like that abbreviation so I choosed LD for Light Destroyer.

For a TB yours are rather slow, aren´t they? A TBs main weapon are its torpedos so it needs to dash in, launch its TTs and retreat. To do so 31,5kn may be too slow and 3 TTs not enough for a successful salvo.

Am I wrong?

HoOmAn

Perhaps a bit slower than other TBs, but fast enough IMO, just check the following linK:

http://www.german-navy.de/kriegsmarine/s…/mowe/tech.html

The ship is almost double the size and the tonnage, yet is almost the same speed. 3 TTs might not be enough for a succesful salvo, I´m not sure, but I´m almost certain that these ships would never act alone, perhaps in squadrons of 4-5 ships, and that would make the difference.

There were also some other vessels historically classed as TBs in other navies that are almost the same speed or slower, for example:

- Otori class IJN, 1934, 28 knots, 595t (Jane´s data, could be wrong)
- Kuri class IJN, 1920, classed as DD, 31,5 knots, 4TT, 770t

On the other hand the french Melpomene class, 1935, almost the same size, is much faster, 34.5 knots, but they only have 2 TTs...

I don´t think you´re wrong or right, I guess there are many different design philosophies and place for many different kind of vessels.

Well I like the design, Atlantis lacks some of these smaller more nimble ships. Now with the CT limiting the numbers of ships to be built I'll surely be looking at these smaller designs with great interest. Shes still a decent threat to a loitering BB.

I definitly vote to call them the Defiant-class.

After producing an armoured TB I'm now going cold on the 600ton ship. The appeal is that you can build 3 per slip per year. However, they are just not capable enough - as they were in RL. I'm leaning to a Hunt type ship but without torps (as they are illegal) rather than a fast TB. This will free up DD's for real DD work rather than escort.

Cheers,

If I ever can spare the resources, I can see both types in service in India - a Hunt-type as an ASW/AA escort, and a TB for littorial actions along my coasts (or somebody else's coast, if appropriate).

But for now, I'm still years away from getting up to my limits for regular warships, and will concentrate on building them before I turn to less capable alternatives.

I want to avoid 'block obsolecence' with regards to DD. I'm working on 32 DD at 2 per year with a service life of 16 years to have a perpetual CT level fleet. I have capacity for 8 per year but I think I'm going for a force structure of 32 Escorts even though I could build 180 'escorts'. The lack of torps in this capacity of ship will be a problem.

Cheers,