WesWorld

Here are a pair of ships I plan to build starting 1930. Both are also available in a slower (29kts) longer legged (9,000mi, at 12kts) version for the ocean escort role.


The first one can be considered a picket boat. Its role will be to operate a small floatplane for scouting. But it can also be modified for other missions including:
Fast minelayer
Fast Minesweeper
Flag boat for cutters (see below)
Rescue ship

Enter ship name, Australia Patrol Scout laid down 1930

Displacement:
598 t light; 614 t standard; 704 t normal; 776 t full load

Dimensions: Length overall / water x beam x draught
279.00 ft / 279.00 ft x 24.00 ft x 9.20 ft (normal load)
85.04 m / 85.04 m x 7.32 m x 2.80 m

Armament:
1 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1930 Model
Breech loading gun in deck mount
on centreline forward
2 - 1.57" / 40.0 mm guns in single mounts, 1.95lbs / 0.89kg shells, 1930 Model
Breech loading guns in deck mounts
on side, all amidships
4 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1930 Model
Breech loading guns in deck mounts
on side, evenly spread
Weight of broadside 37 lbs / 17 kg
Shells per gun, main battery: 90
4 - 21.0" / 533.4 mm above water torpedoes

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.20" / 30 mm - -

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 18,090 shp / 13,495 Kw = 32.00 kts
Range 5,900nm at 12.00 kts
Bunker at max displacement = 162 tons

Complement:
67 - 88

Cost:
£0.313 million / $1.250 million

Distribution of weights at normal displacement:
Armament: 5 tons, 0.7 %
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: 357 tons, 50.7 %
Hull, fittings & equipment: 209 tons, 29.7 %
Fuel, ammunition & stores: 106 tons, 15.0 %
Miscellaneous weights: 25 tons, 3.6 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
221 lbs / 100 Kg = 6.9 x 4.0 " / 102 mm shells or 0.2 torpedoes
Stability (Unstable if below 1.00): 1.27
Metacentric height 0.9 ft / 0.3 m
Roll period: 10.6 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.11
Seaboat quality (Average = 1.00): 1.22

Hull form characteristics:
Hull has low quarterdeck
and transom stern
Block coefficient: 0.400
Length to Beam Ratio: 11.63 : 1
'Natural speed' for length: 19.09 kts
Power going to wave formation at top speed: 68 %
Trim (Max stability = 0, Max steadiness = 100): 58
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: 17.00 ft / 5.18 m
- Forecastle (20 %): 12.90 ft / 3.93 m
- Mid (50 %): 12.90 ft / 3.93 m
- Quarterdeck (15 %): 9.00 ft / 2.74 m (12.90 ft / 3.93 m before break)
- Stern: 9.00 ft / 2.74 m
- Average freeboard: 12.64 ft / 3.85 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 172.4 %
- Above water (accommodation/working, high = better): 92.3 %
Waterplane Area: 4,278 Square feet or 397 Square metres
Displacement factor (Displacement / loading): 61 %
Structure weight / hull surface area: 21 lbs/sq ft or 102 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.42
- Longitudinal: 2.73
- Overall: 0.51
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


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This one is based on the same hull. Its a conventional fast patrol boat/ASW sloop.

Enter ship name, Australia Patrol Cutter laid down 1930

Displacement:
593 t light; 614 t standard; 704 t normal; 776 t full load

Dimensions: Length overall / water x beam x draught
279.00 ft / 279.00 ft x 24.00 ft x 9.20 ft (normal load)
85.04 m / 85.04 m x 7.32 m x 2.80 m

Armament:
3 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1930 Model
Breech loading guns in deck mounts
on centreline ends, majority forward, 1 raised mount
4 - 1.57" / 40.0 mm guns (2x2 guns), 1.95lbs / 0.89kg shells, 1930 Model
Breech loading guns in deck mounts
on centreline, evenly spread
4 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1930 Model
Breech loading guns in deck mounts
on side, evenly spread
Weight of broadside 105 lbs / 48 kg
Shells per gun, main battery: 120
4 - 21.0" / 533.4 mm above water torpedoes

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.20" / 30 mm - -

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 18,090 shp / 13,495 Kw = 32.00 kts
Range 5,900nm at 12.00 kts
Bunker at max displacement = 162 tons

Complement:
67 - 88

Cost:
£0.333 million / $1.332 million

Distribution of weights at normal displacement:
Armament: 13 tons, 1.9 %
Armour: 8 tons, 1.1 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 8 tons, 1.1 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 342 tons, 48.6 %
Hull, fittings & equipment: 220 tons, 31.2 %
Fuel, ammunition & stores: 111 tons, 15.8 %
Miscellaneous weights: 10 tons, 1.4 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
220 lbs / 100 Kg = 6.9 x 4.0 " / 102 mm shells or 0.2 torpedoes
Stability (Unstable if below 1.00): 1.30
Metacentric height 0.9 ft / 0.3 m
Roll period: 10.4 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.32
Seaboat quality (Average = 1.00): 1.23

Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.400
Length to Beam Ratio: 11.63 : 1
'Natural speed' for length: 19.09 kts
Power going to wave formation at top speed: 68 %
Trim (Max stability = 0, Max steadiness = 100): 57
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: 17.00 ft / 5.18 m
- Forecastle (20 %): 12.50 ft / 3.81 m
- Mid (50 %): 12.50 ft / 3.81 m
- Quarterdeck (15 %): 12.00 ft / 3.66 m
- Stern: 12.00 ft / 3.66 m
- Average freeboard: 12.70 ft / 3.87 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 172.5 %
- Above water (accommodation/working, high = better): 88.5 %
Waterplane Area: 4,278 Square feet or 397 Square metres
Displacement factor (Displacement / loading): 58 %
Structure weight / hull surface area: 22 lbs/sq ft or 107 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.43
- Longitudinal: 2.91
- Overall: 0.52
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is cramped
Ship has slow, easy roll, a good, steady gun platform
Good seaboat, rides out heavy weather easily

The cross-sectional strength should be 0.50 at least. Really if you want Oceanic escorts you probably need 1.00+, the more the better. For an Oceanic escort you want something like the Flower - Class corvettes which are nearly twice as large.

Oh, oh!

Quoted

For an Oceanic escort you want something like the Flower - Class corvettes which are nearly twice as large.

Well I do have the 900t frigates, but I want something faster. I think Ill build the 29ky version and keep the faster version for the future.

Quoted

The Royal Navy is considering the type to fill a significant gap in its' light craft.

There is an expected need for approximately two hundred such ships, which need not be of the same design.

If anyone else is likely to make a submission, I'll start a topic to state requirements.

And here is my proposal:

Enter ship name, Australia Patrol Cutter laid down 1931

Displacement:
549 t light; 570 t standard; 704 t normal; 810 t full load

Dimensions: Length overall / water x beam x draught
270.00 ft / 270.00 ft x 24.00 ft x 9.50 ft (normal load)
82.30 m / 82.30 m x 7.32 m x 2.90 m

Armament:
3 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1931 Model
Breech loading guns in deck mounts
on centreline ends, majority forward, 1 raised mount
4 - 1.57" / 40.0 mm guns (2x2 guns), 1.95lbs / 0.88kg shells, 1931 Model
Breech loading guns in deck mounts
on centreline, evenly spread
4 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1931 Model
Breech loading guns in deck mounts
on side, evenly spread
Weight of broadside 105 lbs / 48 kg
Shells per gun, main battery: 120
4 - 21.0" / 533.4 mm above water torpedoes

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.20" / 30 mm - -

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 12,267 shp / 9,151 Kw = 29.00 kts
Range 9,000nm at 12.00 kts
Bunker at max displacement = 240 tons

Complement:
67 - 88

Cost:
£0.321 million / $1.285 million

Distribution of weights at normal displacement:
Armament: 13 tons, 1.9 %
Armour: 8 tons, 1.1 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 8 tons, 1.1 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 310 tons, 44.0 %
Hull, fittings & equipment: 208 tons, 29.6 %
Fuel, ammunition & stores: 155 tons, 22.0 %
Miscellaneous weights: 10 tons, 1.4 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
277 lbs / 126 Kg = 8.6 x 4.0 " / 102 mm shells or 0.2 torpedoes
Stability (Unstable if below 1.00): 1.38
Metacentric height 1.0 ft / 0.3 m
Roll period: 9.9 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.27
Seaboat quality (Average = 1.00): 1.25

Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.400
Length to Beam Ratio: 11.25 : 1
'Natural speed' for length: 18.82 kts
Power going to wave formation at top speed: 64 %
Trim (Max stability = 0, Max steadiness = 100): 56
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: 15.00 ft / 4.57 m
- Forecastle (20 %): 11.00 ft / 3.35 m
- Mid (50 %): 11.00 ft / 3.35 m
- Quarterdeck (15 %): 11.00 ft / 3.35 m
- Stern: 11.00 ft / 3.35 m
- Average freeboard: 11.32 ft / 3.45 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 158.0 %
- Above water (accommodation/working, high = better): 74.4 %
Waterplane Area: 4,140 Square feet or 385 Square metres
Displacement factor (Displacement / loading): 82 %
Structure weight / hull surface area: 24 lbs/sq ft or 115 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.51
- Longitudinal: 2.23
- Overall: 0.59
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is cramped
Ship has slow, easy roll, a good, steady gun platform
Good seaboat, rides out heavy weather easily

If you want an antisubmarine design, that is about 28-29knts for Oceanic work, with a few 4" guns you are going far too small. Size is imperative for Oceanic work. Really you want something like the Hunt Class. Or to emphasize the ASW look at the River Class Frigates.

But a larger ship involves either using limited tonnage or slower speeds. Neither of which will work.

Depends on what you're escorting. For escorting mercantile shipping, 24 knots will work just fine, you'll be twice as fast as most merchants of the day. For escorting warships, no, it won't work, but then, that's more the job of the fleet destroyers than DEs anyway. And your fleet's relatively small (though stronger than mine at the moment), so a large number of ASW escorts wouldn't be necessary.

I have my doubts about a 600 t ship functioning well as an oceanic escort. The Flower class corvette was a larger ship, with less speed and armament, and even it was intended as a coastal escort, operating on the open ocean out of necessity.

The speed of the Australian designs is excessive for merchant protection; and the length to beam ratio, combined with the low (but legal, yes) hull strength should make for some mishaps on the high seas.

Quoted

But a larger ship involves either using limited tonnage or slower speeds. Neither of which will work.

You want a captial ship escort; use a destroyer or cruiser

You want a merchant ship escort, a speed of 20knts is fine. The speed of a "slow" convoy was 9knts. A "fast" convoy was 12knts. Then there were a few unescorted ships, banana boats et al which could go 18-20knts+ and so didn't have the need for escorts.