WesWorld

[SIZE=3]High Speed Patrol Torpedo Vessel[/SIZE]
Displacement: 154 tonnes (light), 178 tonnes (normal)
Length: 40 m (131.3 ft) waterline; 42.55 m (139.6 ft) overall
Beam: 5.4 m (17.7 ft)
Draught: 1.65 m (5.4 ft) full load
Machinery: 2 Clerget 14G marine diesel radial engines, both of 850hp; plus 1 geared Indret steam turbine; two shafts
Speed: 20.5 knots (diesel only); 33.2 knots (steam and diesel, sprint speed)
Cruising range: 780nm at 19 knots (diesel only)
Crew: 31 men
Armament:
- 1 x 75mm deck gun forward
- 2 x 40mm AA guns aft
- 2 x 20mm HS.404 cannon amidships
- 2 x 550mm torpedoes
- 2 racks for six depth charges or four naval mines

Discussion: This craft was a result of a Chilean RFP. DCNS put together some designs to offer to the Chilean RFP but the offer from Denny was judged better developed and better met the Chilean requirements; this resulted in the Sea Gunboat Vina del Mar . DCNS continued refining their design with an idea towards other potential export customers, or French service. This craft is intended primarily as a substitute for motor torpedo boats in regions where rough seas may curtail regular MTB operation.

[SIZE=3]Motor Launch Type 1[/SIZE]
Displacement: 90 tonnes (light), 111 tonnes (normal)
Length: 35 m (114.8 ft) waterline; 37.22 m (122.1 ft) overall
Beam: 5.55 m (18.2 ft)
Draught: 1.35 m (4.4 ft) full load
Machinery: 2 Clerget 14F marine diesel radial engines, both of 720hp; three shafts
Speed: 19 knots
Cruising range: 1200 nm at 15 knots
Crew: 19 men
Armament:
- 1 x 40mm AA guns aft
- 2 x 20mm HS.404 cannon amidships
- 2 racks for six depth charges or four naval mines

[SIZE=3]Motor Launch Type 2[/SIZE]
Displacement: 48 tonnes (light), 56 tonnes (loaded)
Length: 22 m (72.18 ft) waterline; 23.75 m (77.9 ft) overall
Beam: 4.9 m (16 ft)
Draught: 1.4 m (4.6 ft) full load
Machinery: 2 x 225hp Renault marine diesel engines; 2 shafts
Speed: 14 knots
Cruising range: 1200 nm at 12 knots
Crew: 13 men
Armament:
- 2 x 20mm HS.404 cannon on centerline forward and centerline aft
- 2 x 12.7mm Hotchkiss MGs side amidships
- 2 racks for six depth charges or four naval mines

Discussion: These two motor launches are proposed for use as light coastal patrol vessels, guarding friendly ports against infiltrators or serving as light utility craft in harbor.

[SIZE=3]High Speed Patrol Launch[/SIZE]
Displacement: 22 tonnes (light), 24 tonnes (normal)
Length: 20 m (65.6 ft) overall
Beam: 5.2 m (17 ft)
Draught: 1.1 m (3.6 ft) full load
Machinery: 2 Clerget 14G marine diesel radial engines, both of 850hp, driving two shafts
Speed: 36 knots
Crew: 9 men
Armament:
- 2 x 20mm HS.404 cannon
- 1 rack for three depth charges or two naval mines

Discussion: This proposal is a higher-speed version of the vessel above, with less capacity and more speed.

Quoted

Originally posted by Brockpaine
[SIZE=3]High Speed Patrol Torpedo Vessel[/SIZE]

Machinery: 2 Clerget 14G marine diesel radial engines, both of 850hp; plus 1 geared Indret steam turbine; two shafts
Speed: 20.5 knots (diesel only); 33.2 knots (steam and diesel, sprint speed)

My chief concern is the application of a mixed powerplant to such a small vessel - the practicality of having two sets of fuel tanks - one for diesel oil and the other for bunker fuel. On a larger vessel there is space enough to allow for that - in such a small hull I think that there may not be. Perhaps a third diesel engine of greater HP for sprints?

Quoted

Originally posted by Brockpaine
[SIZE=3]Motor Launch Type 1[/SIZE]

Machinery: 2 Clerget 14F marine diesel radial engines, both of 720hp; three shafts
Speed: 19 knots

Two engines, three shafts? That seems odd, or has the DCNS come up with something new?

[SIZE=3]Vedette Rapide Type 1[/SIZE]
Displacement: 75 tonnes (light), 178 tonnes (normal)
Length: 31 m (101.7 ft) waterline; 33 m (108.1 ft) overall
Beam: 5 m (16.4 ft)
Draught: 1.2 m (3.9 ft) full load
Machinery: 2 Clerget 16Hd marine diesel engines, both of 1,915hp; two shafts
Speed: 39 knots
Cruising range: 1100nm at 25 knots
Crew: 25 men
Armament:
- 1 x 40mm AA guns aft
- 2 x 20mm HS.404 cannon forward
- 1 x 20mm HS.404 cannon aft
- 2 x 550mm torpedoes

[SIZE=3]Vedette Rapide Type 2[/SIZE]
Displacement: 45 tons
Length: 23 m
Beam: 5.8 m
Draught: 1.5 m
Machinery: 2 Clerget 16Hd marine diesel engines, both of 1,915hp; two shafts
Speed: 44 knots
Cruising range: 1100nm at 25 knots
Crew: 16 men
Armament:
- 1 x 40mm AA guns aft
- 1 x 20mm HS.404 cannon aft
- 2 x 550mm torpedoes

Discussion: Theoretical French-designed follow-on to the Schnellboot Typ 1936 acquired for MTB trials evaluations. One closely follows the Schnellboot model (a larger craft with better seakeeping) while the second follows the smaller pattern better-established in other countries like Britain, Atlantis, and Italy.

Quoted

Originally posted by BruceDuncan

Quoted

Originally posted by Brockpaine
[SIZE=3]Motor Launch Type 1[/SIZE]

Machinery: 2 Clerget 14F marine diesel radial engines, both of 720hp; three shafts
Speed: 19 knots

Two engines, three shafts? That seems odd, or has the DCNS come up with something new?

Typo. Designed for three shafts then stuck two engines on it. I think you can probably gear the engines to run different shafts, but that's probably not an efficient way of doing things.

Alternate version with all-diesel propulsion.

Quoted

[SIZE=3]High Speed Patrol Torpedo Vessel[/SIZE]
Displacement: 154 tonnes (light), 178 tonnes (normal)
Length: 40 m (131.3 ft) waterline; 42.55 m (139.6 ft) overall
Beam: 5.4 m (17.7 ft)
Draught: 1.65 m (5.4 ft) full load
Machinery: 4 Clerget 16He marine diesel engines, all of 2,400hp
Speed: 20.5 knots (cruising); 33.2 knots (sprint speed)
Cruising range: 780nm at 19 knots
Crew: 31 men
Armament:
- 1 x 75mm deck gun forward
- 2 x 40mm AA guns aft
- 2 x 20mm HS.404 cannon amidships
- 2 x 550mm torpedoes
- 2 racks for six depth charges or four naval mines

The high speed patrol torpedo vessel looks to be an interesting design, but I don't see it as meeting any French need. Smaller navies, without larger vessels, might find it a useful addition to their inventory. This would look to be a useful 'littoral mosquito'.

I like the look of that Brock, Denmark may be interested in licencing the design......

Quoted

Originally posted by Commodore Green
I like the look of that Brock, Denmark may be interested in licencing the design......

I've budgeted for a test craft in Q4; when it's done the Danes would be welcome to have a look at it, if they're interested in perhaps licensing the design.

Quoted

Originally posted by BruceDuncan

Quoted

Originally posted by Brockpaine
[SIZE=3]High Speed Patrol Torpedo Vessel[/SIZE]

Machinery: 2 Clerget 14G marine diesel radial engines, both of 850hp; plus 1 geared Indret steam turbine; two shafts
Speed: 20.5 knots (diesel only); 33.2 knots (steam and diesel, sprint speed)

My chief concern is the application of a mixed powerplant to such a small vessel - the practicality of having two sets of fuel tanks - one for diesel oil and the other for bunker fuel. On a larger vessel there is space enough to allow for that - in such a small hull I think that there may not be. Perhaps a third diesel engine of greater HP for sprints?

Well, you don't actually need two separate types of fuels. A boiler will run just fine on diesel oil (In fact it'll run better) and diesel engines were invented to run on bunker oil.

Quoted

Originally posted by Brockpaine

Quoted

Originally posted by Commodore Green
I like the look of that Brock, Denmark may be interested in licencing the design......

I've budgeted for a test craft in Q4; when it's done the Danes would be welcome to have a look at it, if they're interested in perhaps licensing the design.

As a matter of interest, what's she based on?
I assume she isn't simmed.........

No, not simmed. Well, I simmed the hull out to get the displacement, but didn't sim the speed onto her.

Concept's essentially based on the British Denny Steam Gunboat (SGB) from 1941. Basically, a larger vessel to stave off German Schnellboots in the English Channel.

In WW, the Chileans wanted something similar to use as a high-speed coastal patrol boat; the current theory is that a squadron of fast (33 knot) light combatants of 200-250 tons would be a useful alternative to MTBs and small destroyers. (The Chileans basically wanted something to do an MTB's job, but weren't happy with the seakeeping of MTBs.) The Chileans picked the larger British design by Denny - the historical Steam Gun Boat - while this is the proposed French design which does the same thing.

The French aren't fully sold on the idea yet, but they like the more roomy accommodations, better seakeeping, and the armament they could fit on the design. One alternative was to turn France's current 47mm AT gun into an automatic twin DP mount (or scaling up the French 40mm gun), but that would require a weapons development project, and I didn't want to get into that with this design.

Denny would be open to foreign sales too if this market gets bigger.

[SIZE=3]CDI-290 (Chaland de débarquement d'infanterie), French Landing Craft Infantry laid down 1941[/SIZE]
(Landing craft variant)

Displacement:
218 t light; 232 t standard; 291 t normal; 339 t full load

Dimensions: Length overall / water x beam x draught
170.46 ft / 164.04 ft x 22.97 ft x 4.92 ft (normal load)
51.96 m / 50.00 m x 7.00 m x 1.50 m

Armament:
2 - 1.57" / 40.0 mm guns (1x2 guns), 1.95lbs / 0.89kg shells, 1941 Model
Anti-aircraft guns in deck mount
on centreline forward
2 - 0.91" / 23.0 mm guns (1x2 guns), 0.37lbs / 0.17kg shells, 1941 Model
Machine guns in deck mount
on centreline aft, all raised guns - superfiring
2 - 0.91" / 23.0 mm guns in single mounts, 0.37lbs / 0.17kg shells, 1941 Model
Machine guns in deck mounts
on side, all aft, all raised mounts - superfiring
Weight of broadside 5 lbs / 2 kg
Shells per gun, main battery: 2,000

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Ends: 0.59" / 15 mm 22.97 ft / 7.00 m 9.84 ft / 3.00 m
141.08 ft / 43.00 m Unarmoured ends

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.79" / 20 mm 0.39" / 10 mm -
2nd: 0.59" / 15 mm 0.20" / 5 mm -
3rd: 0.59" / 15 mm 0.20" / 5 mm -

- Conning tower: 0.79" / 20 mm

Machinery:
Diesel Internal combustion motors,
Geared drive, 2 shafts, 913 shp / 681 Kw = 16.00 kts
Range 4,000nm at 15.00 kts
Bunker at max displacement = 108 tons

Complement:
34 - 45

Cost:
£0.072 million / $0.286 million

Distribution of weights at normal displacement:
Armament: 1 tons, 0.2 %
Armour: 7 tons, 2.5 %
- Belts: 5 tons, 1.7 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 1 tons, 0.5 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 1 tons, 0.3 %
Machinery: 24 tons, 8.3 %
Hull, fittings & equipment: 121 tons, 41.5 %
Fuel, ammunition & stores: 73 tons, 25.2 %
Miscellaneous weights: 65 tons, 22.3 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
879 lbs / 399 Kg = 450.3 x 1.6 " / 40 mm shells or 0.8 torpedoes
Stability (Unstable if below 1.00): 1.14
Metacentric height 0.7 ft / 0.2 m
Roll period: 11.5 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.02
Seaboat quality (Average = 1.00): 1.50

Hull form characteristics:
Hull has raised forecastle
and transom stern
Block coefficient: 0.550
Length to Beam Ratio: 7.14 : 1
'Natural speed' for length: 14.94 kts
Power going to wave formation at top speed: 55 %
Trim (Max stability = 0, Max steadiness = 100): 47
Bow angle (Positive = bow angles forward): 15.00 degrees
Stern overhang: 2.46 ft / 0.75 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 14.76 ft / 4.50 m
- Forecastle (15 %): 13.94 ft / 4.25 m (8.20 ft / 2.50 m aft of break)
- Mid (50 %): 8.20 ft / 2.50 m
- Quarterdeck (15 %): 8.20 ft / 2.50 m
- Stern: 8.20 ft / 2.50 m
- Average freeboard: 9.11 ft / 2.78 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 56.7 %
- Above water (accommodation/working, high = better): 125.8 %
Waterplane Area: 2,737 Square feet or 254 Square metres
Displacement factor (Displacement / loading): 232 %
Structure weight / hull surface area: 28 lbs/sq ft or 136 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.92
- Longitudinal: 3.10
- Overall: 1.04
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Good seaboat, rides out heavy weather easily

[SIZE=3]CDC-290 (Chaland de débarquement Canonnière), French Landing Craft Gunboat laid down 1942[/SIZE]
(Gunboat version of the above CDI-290, with increased armament)

Displacement:
218 t light; 232 t standard; 291 t normal; 339 t full load

Dimensions: Length overall / water x beam x draught
170.46 ft / 164.04 ft x 22.97 ft x 4.92 ft (normal load)
51.96 m / 50.00 m x 7.00 m x 1.50 m

Armament:
1 - 2.95" / 75.0 mm guns in single mounts, 12.87lbs / 5.84kg shells, 1942 Model
Dual purpose gun in deck mount
on centreline forward
2 - 1.57" / 40.0 mm guns (1x2 guns), 1.95lbs / 0.89kg shells, 1942 Model
Anti-aircraft guns in deck mount
on centreline aft, all raised guns - superfiring
2 - 0.91" / 23.0 mm guns in single mounts, 0.37lbs / 0.17kg shells, 1942 Model
Machine guns in deck mounts
on side, all aft, all raised mounts - superfiring
Weight of broadside 18 lbs / 8 kg
Shells per gun, main battery: 750

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Ends: 0.59" / 15 mm 22.97 ft / 7.00 m 9.84 ft / 3.00 m
141.08 ft / 43.00 m Unarmoured ends

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.79" / 20 mm 0.39" / 10 mm -
2nd: 0.59" / 15 mm 0.20" / 5 mm -
3rd: 0.59" / 15 mm 0.20" / 5 mm -

- Conning tower: 0.79" / 20 mm

Machinery:
Diesel Internal combustion motors,
Geared drive, 2 shafts, 913 shp / 681 Kw = 16.00 kts
Range 4,000nm at 15.00 kts
Bunker at max displacement = 107 tons

Complement:
34 - 45

Cost:
£0.081 million / $0.326 million

Distribution of weights at normal displacement:
Armament: 2 tons, 0.8 %
Armour: 8 tons, 2.6 %
- Belts: 5 tons, 1.7 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 2 tons, 0.7 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 1 tons, 0.3 %
Machinery: 24 tons, 8.2 %
Hull, fittings & equipment: 119 tons, 40.8 %
Fuel, ammunition & stores: 74 tons, 25.3 %
Miscellaneous weights: 65 tons, 22.3 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
829 lbs / 376 Kg = 64.4 x 3.0 " / 75 mm shells or 0.8 torpedoes
Stability (Unstable if below 1.00): 1.15
Metacentric height 0.7 ft / 0.2 m
Roll period: 11.4 seconds
Steadiness - As gun platform (Average = 50 %): 71 %
- Recoil effect (Restricted arc if above 1.00): 0.06
Seaboat quality (Average = 1.00): 1.50

Hull form characteristics:
Hull has raised forecastle
and transom stern
Block coefficient: 0.550
Length to Beam Ratio: 7.14 : 1
'Natural speed' for length: 14.94 kts
Power going to wave formation at top speed: 55 %
Trim (Max stability = 0, Max steadiness = 100): 47
Bow angle (Positive = bow angles forward): 15.00 degrees
Stern overhang: 2.46 ft / 0.75 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 14.76 ft / 4.50 m
- Forecastle (15 %): 13.94 ft / 4.25 m (8.20 ft / 2.50 m aft of break)
- Mid (50 %): 8.20 ft / 2.50 m
- Quarterdeck (15 %): 8.20 ft / 2.50 m
- Stern: 8.20 ft / 2.50 m
- Average freeboard: 9.11 ft / 2.78 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 60.3 %
- Above water (accommodation/working, high = better): 125.8 %
Waterplane Area: 2,737 Square feet or 254 Square metres
Displacement factor (Displacement / loading): 211 %
Structure weight / hull surface area: 27 lbs/sq ft or 134 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.88
- Longitudinal: 3.05
- Overall: 1.00
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable, can fire her guns in the heaviest weather

Breakdown of Miscellaneous Weights:
- 2 tons to mount four Mortier de 120mm Mle1935 infantry mortars

Notes:
This vessel is designed to provide close escort to a leading wave of landing craft, beaching alongside the regular landing craft and using its 75mm deck gun and the battery of 120mm mortars to provide close supporting firepower to the disembarking infantry.

[SIZE=3]CSM-125 (Chasseur de sous-marins), French Submarine Chaser laid down 1942[/SIZE]

Displacement:
96 t light; 102 t standard; 125 t normal; 143 t full load

Dimensions: Length overall / water x beam x draught
117.22 ft / 114.83 ft x 14.76 ft x 5.74 ft (normal load)
35.73 m / 35.00 m x 4.50 m x 1.75 m

Armament:
1 - 2.95" / 75.0 mm guns in single mounts, 12.87lbs / 5.84kg shells, 1942 Model
Dual purpose gun in deck mount
on centreline forward
2 - 0.91" / 23.0 mm guns (1x2 guns), 0.37lbs / 0.17kg shells, 1942 Model
Machine guns in deck mount
on side amidships
Weight of broadside 14 lbs / 6 kg
Shells per gun, main battery: 450

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.55" / 14 mm 0.31" / 8 mm -
2nd: 0.55" / 14 mm 0.31" / 8 mm -

- Conning tower: 0.31" / 8 mm

Machinery:
Diesel Internal combustion motors,
Geared drive, 2 shafts, 919 shp / 686 Kw = 18.00 kts
Range 2,500nm at 15.00 kts
Bunker at max displacement = 41 tons

Complement:
18 - 24

Cost:
£0.052 million / $0.208 million

Distribution of weights at normal displacement:
Armament: 2 tons, 1.4 %
Armour: 1 tons, 1.1 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 1 tons, 0.9 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.1 %
Machinery: 24 tons, 19.2 %
Hull, fittings & equipment: 54 tons, 43.2 %
Fuel, ammunition & stores: 29 tons, 23.2 %
Miscellaneous weights: 15 tons, 12.0 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
217 lbs / 98 Kg = 16.9 x 3.0 " / 75 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.10
Metacentric height 0.3 ft / 0.1 m
Roll period: 10.7 seconds
Steadiness - As gun platform (Average = 50 %): 52 %
- Recoil effect (Restricted arc if above 1.00): 0.19
Seaboat quality (Average = 1.00): 1.38

Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.450
Length to Beam Ratio: 7.78 : 1
'Natural speed' for length: 12.57 kts
Power going to wave formation at top speed: 68 %
Trim (Max stability = 0, Max steadiness = 100): 38
Bow angle (Positive = bow angles forward): 10.00 degrees
Stern overhang: 0.66 ft / 0.20 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 9.84 ft / 3.00 m
- Forecastle (20 %): 8.53 ft / 2.60 m
- Mid (50 %): 7.22 ft / 2.20 m
- Quarterdeck (15 %): 7.22 ft / 2.20 m
- Stern: 7.22 ft / 2.20 m
- Average freeboard: 7.78 ft / 2.37 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 88.4 %
- Above water (accommodation/working, high = better): 89.4 %
Waterplane Area: 1,123 Square feet or 104 Square metres
Displacement factor (Displacement / loading): 161 %
Structure weight / hull surface area: 21 lbs/sq ft or 101 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.79
- Longitudinal: 9.07
- Overall: 1.00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is cramped
Good seaboat, rides out heavy weather easily

Very similar to Atlantean designs, allthough not surprisingly they have vastly superior propulsion systems enabling them to have twice the range of their Atlantean counterparts on less tonnage.

Personally I'd like to see some heavier rapid fire weapons able to rake Sub decks, like 57-37mm guns.

There could be a twin 40mm added aft, yes; I don't want to ditch the 75mm gun, however.