WesWorld

This is a planned German escort vessel, built on the same hull as the R-11 class minehunters but equipped with ASW sonar rather than minehunting/minesweeping gear. She can still lay mines, like her R-11 class cousins, so future mine operations flotillas might well contain some F-1 class vessels to provide organic anti-submarine protection.


F-1, German Escort laid down 1931

F-1 - laid down 1931

Displacement:
539 t light; 568 t standard; 678 t normal; 766 t full load

Dimensions: Length overall / water x beam x draught
235.87 ft / 229.66 ft x 26.25 ft x 7.87 ft (normal load)
71.89 m / 70.00 m x 8.00 m x 2.40 m

Armament:
4 - 4.13" / 105 mm guns (2x2 guns), 35.32lbs / 16.02kg shells, 1931 Model
Dual purpose guns in deck mounts
on centreline ends, evenly spread
4 - 1.46" / 37.0 mm guns (2x2 guns), 1.55lbs / 0.70kg shells, 1929 Model
Anti-aircraft guns in deck mounts
on centreline ends, evenly spread, all raised mounts
4 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1928 Model
Machine guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 148 lbs / 67 kg
Shells per gun, main battery: 180

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.79" / 20 mm - -
2nd: 0.39" / 10 mm - -

- Conning tower: 1.97" / 50 mm

Machinery:
Diesel Internal combustion motors,
Geared drive, 2 shafts, 9,152 shp / 6,827 Kw = 25.00 kts
Range 4,000nm at 15.00 kts
Bunker at max displacement = 197 tons

Complement:
66 - 86

Cost:
£0.298 million / $1.191 million

Distribution of weights at normal displacement:
Armament: 19 tons, 2.7 %
Armour: 10 tons, 1.4 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 6 tons, 0.9 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 3 tons, 0.5 %
Machinery: 241 tons, 35.5 %
Hull, fittings & equipment: 190 tons, 28.0 %
Fuel, ammunition & stores: 139 tons, 20.4 %
Miscellaneous weights: 80 tons, 11.8 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
282 lbs / 128 Kg = 8.0 x 4.1 " / 105 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.25
Metacentric height 1.0 ft / 0.3 m
Roll period: 11.0 seconds
Steadiness - As gun platform (Average = 50 %): 64 %
- Recoil effect (Restricted arc if above 1.00): 0.32
Seaboat quality (Average = 1.00): 1.29

Hull form characteristics:
Hull has raised forecastle
Block coefficient: 0.500
Length to Beam Ratio: 8.75 : 1
'Natural speed' for length: 15.15 kts
Power going to wave formation at top speed: 67 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 15.00 degrees
Stern overhang: 1.64 ft / 0.50 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 17.06 ft / 5.20 m
- Forecastle (33 %): 16.40 ft / 5.00 m (10.50 ft / 3.20 m aft of break)
- Mid (50 %): 10.50 ft / 3.20 m
- Quarterdeck (15 %): 10.50 ft / 3.20 m
- Stern: 10.50 ft / 3.20 m
- Average freeboard: 12.53 ft / 3.82 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 149.2 %
- Above water (accommodation/working, high = better): 121.7 %
Waterplane Area: 4,016 Square feet or 373 Square metres
Displacement factor (Displacement / loading): 86 %
Structure weight / hull surface area: 23 lbs/sq ft or 113 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 2.96
- Overall: 0.60
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is excellent
Good seaboat, rides out heavy weather easily

10 tons reserved for depth charge rails and depth charges.

30 tons reserved for sonar

40 tons reserved for mines and growth.

Is 25kn her official speed?

Her main armament is quite heavy but she doesn´t have that many shells for her guns...

Why a conning tower on such a vessel?

In general she´s not a bad design....

Yep, 25 knots is her official speed (and her actual speed, come to that). As a vessel under 600 tons standard, her speed doesn't matter for CT purposes, she's an unlimited tonnage vessel.

Granted, her ammunition supply is a little low, perhaps, but then, she's not really intended to engage in long gun battles. If circumstances demand it, though, some of the reserved weight could easily be used to carry additional ammunition.

The conning tower is mostly a national characteristic, and it helps protect the command crew from a submarine's light guns, or from strafing attacks by aircraft.

She might be a bit light & fragile for anything but escorting other light forces, certainly not a vessel to be mucking about in the North Sea in on a bad day.

She's not really intended for operations out in the depths of the North Sea during a storm, though her average freeboard's about the same as your ASW trawler. Her area of operations is more coastal, and the Baltic.

Interesting to compare with Italian escort vessel for 1932. Extremely similar roles but vastly different ships.

Italian Corvetta Cacciasommergibili laid down 1932

Displacement:
611 t light; 628 t standard; 728 t normal; 808 t full load

Dimensions: Length overall / water x beam x draught
207.89 ft / 196.85 ft x 28.54 ft x 8.20 ft (normal load)
63.37 m / 60.00 m x 8.70 m x 2.50 m

Armament:
1 - 3.94" / 100 mm guns in single mounts, 33.07lbs / 15.00kg shells, 1932 Model
Anti-aircraft gun in deck mount
on centreline forward
4 - 0.98" / 25.0 mm guns (2x2 guns), 0.48lbs / 0.22kg shells, 1932 Model
Anti-aircraft guns in deck mounts
on centreline, all aft
4 - 0.98" / 25.0 mm guns in single mounts, 0.48lbs / 0.22kg shells, 1932 Model
Anti-aircraft guns in deck mounts
on side, all forward
Weight of broadside 37 lbs / 17 kg
Shells per gun, main battery: 100
2 - 17.7" / 450 mm above water torpedoes

Machinery:
Diesel Internal combustion motors,
Electric cruising motors plus geared drives, 2 shafts, 4,000 shp / 2,984 Kw = 19.62 kts
Range 6,000nm at 12.00 kts
Bunker at max displacement = 180 tons

Complement:
69 - 91

Cost:
£0.189 million / $0.755 million

Distribution of weights at normal displacement:
Armament: 4 tons, 0.6 %
Machinery: 118 tons, 16.2 %
Hull, fittings & equipment: 450 tons, 61.8 %
Fuel, ammunition & stores: 117 tons, 16.1 %
Miscellaneous weights: 39 tons, 5.4 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
1,897 lbs / 860 Kg = 62.2 x 3.9 " / 100 mm shells or 1.0 torpedoes
Stability (Unstable if below 1.00): 1.14
Metacentric height 1.0 ft / 0.3 m
Roll period: 12.2 seconds
Steadiness - As gun platform (Average = 50 %): 51 %
- Recoil effect (Restricted arc if above 1.00): 0.07
Seaboat quality (Average = 1.00): 1.75

Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0.553
Length to Beam Ratio: 6.90 : 1
'Natural speed' for length: 14.03 kts
Power going to wave formation at top speed: 64 %
Trim (Max stability = 0, Max steadiness = 100): 29
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 3.28 ft / 1.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 21.33 ft / 6.50 m
- Forecastle (20 %): 18.04 ft / 5.50 m
- Mid (60 %): 16.40 ft / 5.00 m (8.20 ft / 2.50 m aft of break)
- Quarterdeck (15 %): 8.20 ft / 2.50 m
- Stern: 8.20 ft / 2.50 m
- Average freeboard: 14.04 ft / 4.28 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 63.9 %
- Above water (accommodation/working, high = better): 123.2 %
Waterplane Area: 3,932 Square feet or 365 Square metres
Displacement factor (Displacement / loading): 235 %
Structure weight / hull surface area: 56 lbs/sq ft or 274 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.25
- Longitudinal: 11.30
- Overall: 1.55
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
Excellent seaboat, comfortable, can fire her guns in the heaviest weather

10t Sonar
2t torpedoes
6t 2xduple 25mm mounts
7t = Scaricabombe
4t = 40 DC + throwers
10t = ASW mortar

And then the In between ship. Nordmarks next class of escort:

F32, Nordmark Frigate laid down 1932

Displacement:
592 t light; 636 t standard; 892 t normal; 1,097 t full load

Dimensions: Length overall / water x beam x draught
233.53 ft / 230.00 ft x 29.00 ft x 9.00 ft (normal load)
71.18 m / 70.10 m x 8.84 m x 2.74 m

Armament:
4 - 4.33" / 110 mm guns (2x2 guns), 40.61lbs / 18.42kg shells, 1932 Model
Dual purpose guns in deck mounts
on centreline ends, evenly spread
8 - 1.46" / 37.0 mm guns (4x2 guns), 1.55lbs / 0.70kg shells, 1932 Model
Anti-aircraft guns in deck mounts
on side, all amidships
8 - 0.79" / 20.0 mm guns (4x2 guns), 0.24lbs / 0.11kg shells, 1932 Model
Machine guns in deck mounts
on side, evenly spread
Weight of broadside 177 lbs / 80 kg
Shells per gun, main battery: 250

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 2.00" / 51 mm 1.00" / 25 mm -
2nd: 2.00" / 51 mm - -
3rd: 1.00" / 25 mm - -

- Conning tower: 1.00" / 25 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 4,375 shp / 3,264 Kw = 20.00 kts
Range 8,000nm at 15.00 kts
Bunker at max displacement = 461 tons

Complement:
81 - 106

Cost:
£0.261 million / $1.043 million

Distribution of weights at normal displacement:
Armament: 22 tons, 2.5 %
Armour: 22 tons, 2.4 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 20 tons, 2.2 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 2 tons, 0.2 %
Machinery: 129 tons, 14.5 %
Hull, fittings & equipment: 339 tons, 38.0 %
Fuel, ammunition & stores: 300 tons, 33.6 %
Miscellaneous weights: 80 tons, 9.0 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
1,566 lbs / 710 Kg = 38.6 x 4.3 " / 110 mm shells or 0.8 torpedoes
Stability (Unstable if below 1.00): 1.21
Metacentric height 1.1 ft / 0.3 m
Roll period: 11.6 seconds
Steadiness - As gun platform (Average = 50 %): 98 %
- Recoil effect (Restricted arc if above 1.00): 0.30
Seaboat quality (Average = 1.00): 1.96

Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0.520
Length to Beam Ratio: 7.93 : 1
'Natural speed' for length: 15.17 kts
Power going to wave formation at top speed: 58 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 10.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 20.00 ft / 6.10 m
- Forecastle (40 %): 15.00 ft / 4.57 m
- Mid (40 %): 15.00 ft / 4.57 m (10.25 ft / 3.12 m aft of break)
- Quarterdeck (15 %): 10.25 ft / 3.12 m
- Stern: 10.25 ft / 3.12 m
- Average freeboard: 12.95 ft / 3.95 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 77.9 %
- Above water (accommodation/working, high = better): 109.1 %
Waterplane Area: 4,526 Square feet or 421 Square metres
Displacement factor (Displacement / loading): 166 %
Structure weight / hull surface area: 39 lbs/sq ft or 190 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.85
- Longitudinal: 4.24
- Overall: 1.00
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is adequate
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable, can fire her guns in the heaviest weather

Misc weight is 30tons for mines, 30tons for ASW, and 20tons stores

Problem with all of these ships is the gun armament. There are good reasons that the historical vessels didn't mount 4 guns. Weight and space being the main problems, but also need. These vessels are not likely to encounter destroyers or larger vessels, but submarines armed with a single gun, MTBs or merchant vessels. The large gun armament is redundant. You want lots of structural strength, ease of maintenance and idiot proof technology. Mines on these vessels? About 10 or so, hardly worth it considering the restrictions on space by mounting rails on the deck. Makes it extremely hard to put DC racks and projectors on them.

I like this quote from www.prinzeugen.com

Quoted

The Kriegsmarine planners failed to anticipate the qualities that would make ships like the British Flower Class successful convoy escorts: they were cheap, uncomplicated, slow and, ultimately, expendible. The Flottenbegleitschiffe were none of these things. They were, after all, German.

Weight allowed for Mines on these ships is probably too much, I might re-design the ships to either have 30tons of ASW or 10tons of ASW and 20tons of Mines. That will certainly give these ships more strength.

As far as the number of Main guns go, these ships are intended to combat anything up to small destroyers.

Gavin's got a valid point - that's a lot of stuff being jammed into a small area. India's Rabkavi class isn't much smaller than this, but I only included 1x10.5 cm, 1x2 35 mm, and a quad 15 mm - and that's enough to fill up the deck plan quite nicely.

Take a look at the historical Minensuchboote 1935 (here), which the R-11 class is based on. The R-11's a little longer (4 meters), and a little shallower (-0.25 m), propelled by diesels instead of boilers and a bit faster. The gun armament's using twin mountings instead of singles, but the main guns are the same, 105mm weapons fore and aft, supported by 37mm and 20mm weapons. Mines and DCs were carried historically without any great difficulty, so there's no reason to think it will be difficult this time.

The comments made about the historical Flottenbegleitschiffe are fine, but have little to do with this vessel, and its role is not deep-sea ASW, but shallow-sea ASW and general escorting vs air, surface, and sub-surface threats.

Chile has two responces to the small destroyer issue. One is overly heavy gunned and the other is still heavily gunned but faster. The Teniente-class has a higher seakeeping because it was expected to do Pacific and Cape Horn patrols.


Teniente Riquelme: Light Destroyer 1925

Chilean Light Destroyer laid down 1925

Displacement:
669 t light; 701 t standard; 749 t normal; 785 t full load

Dimensions: Length overall / water x beam x draught
226.00 ft / 220.00 ft x 27.50 ft x 11.00 ft (normal load)
68.89 m / 67.06 m x 8.38 m x 3.35 m

Armament:
1 - 5.90" / 150 mm guns in single mounts, 102.69lbs / 46.58kg shells, 1925 Model
Breech loading gun in deck mount
on centreline forward
2 - 4.30" / 109 mm guns in single mounts, 39.75lbs / 18.03kg shells, 1925 Model
Breech loading guns in deck mounts
on centreline ends, majority aft, 1 raised mount
2 - 1.46" / 37.0 mm guns (1x2 guns), 1.55lbs / 0.70kg shells, 1925 Model
Anti-aircraft guns in deck mount
on centreline amidships
2 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1925 Model
Machine guns in deck mounts
on side, evenly spread
Weight of broadside 185 lbs / 84 kg
Shells per gun, main battery: 150
5 - 18.0" / 457.2 mm above water torpedoes

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 18,080 shp / 13,488 Kw = 29.00 kts
Range 1,500nm at 15.00 kts (Bunkerage = 87 tons)

Complement:
71 - 93

Cost:
£0.301 million / $1.206 million

Distribution of weights at normal displacement:
Armament: 23 tons, 3.1 %
Machinery: 352 tons, 46.9 %
Hull, fittings & equipment: 284 tons, 37.9 %
Fuel, ammunition & stores: 80 tons, 10.7 %
Miscellaneous weights: 10 tons, 1.3 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
238 lbs / 108 Kg = 2.3 x 5.9 " / 150 mm shells or 0.2 torpedoes
Stability (Unstable if below 1.00): 1.05
Metacentric height 0.8 ft / 0.2 m
Steadiness - As gun platform (Average = 50 %): 84 %
- Recoil effect (Restricted arc if above 1.00): 0.58
Seaboat quality (Average = 1.00): 1.20

Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.394
Length to Beam Ratio: 8.00 : 1
'Natural speed' for length: 14.83 kts
Power going to wave formation at top speed: 73 %
Trim (Max stability = 0, Max steadiness = 100): 70
Bow angle (Positive = bow angles forward): 12.14 degrees
Stern overhang: 1.00 ft / 0.30 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 23.25 ft / 7.09 m
- Forecastle (20 %): 15.75 ft / 4.80 m
- Mid (50 %): 14.00 ft / 4.27 m
- Quarterdeck (15 %): 14.00 ft / 4.27 m
- Stern: 14.00 ft / 4.27 m
- Average freeboard: 15.21 ft / 4.64 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 176.8 %
- Above water (accommodation/working, high = better): 78.8 %
Waterplane Area: 3,508 Square feet or 326 Square metres
Displacement factor (Displacement / loading): 55 %
Structure weight / hull surface area: 30 lbs/sq ft or 147 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 8.37
- Overall: 0.66
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

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Guardia Marina Contrerra: Light Destroyer 1927

Chilean Destroyer laid down 1927

Displacement:
850 t light; 897 t standard; 965 t normal; 1,015 t full load

Dimensions: Length overall / water x beam x draught
300.00 ft / 289.00 ft x 29.00 ft x 10.00 ft (normal load)
91.44 m / 88.09 m x 8.84 m x 3.05 m

Armament:
3 - 4.33" / 110 mm guns in single mounts, 40.59lbs / 18.41kg shells, 1927 Model
Quick firing guns in deck mounts
on centreline ends, majority forward, 1 raised mount
4 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1927 Model
Dual purpose guns in deck mounts
on side, evenly spread
2 - 1.46" / 37.0 mm guns (1x2 guns), 1.55lbs / 0.70kg shells, 1927 Model
Anti-aircraft guns in deck mount
on centreline
6 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1927 Model
Machine guns in deck mounts
on side, evenly spread, 2 raised mounts
Weight of broadside 179 lbs / 81 kg
Shells per gun, main battery: 250
2 - 21.0" / 533.4 mm above water torpedoes

Machinery:
Oil fired boilers, steam turbines,
Direct drive, 2 shafts, 27,500 shp / 20,515 Kw = 32.27 kts
Range 5,000nm at 10.00 kts (Bunkerage = 122 tons)

Complement:
86 - 112

Cost:
£0.431 million / $1.723 million

Distribution of weights at normal displacement:
Armament: 22 tons, 2.3 %
Machinery: 499 tons, 51.7 %
Hull, fittings & equipment: 329 tons, 34.0 %
Fuel, ammunition & stores: 115 tons, 11.9 %
Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
276 lbs / 125 Kg = 6.8 x 4.3 " / 110 mm shells or 0.2 torpedoes
Stability (Unstable if below 1.00): 1.27
Metacentric height 1.2 ft / 0.4 m
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.30
Seaboat quality (Average = 1.00): 1.06

Hull form characteristics:
Hull has rise forward of midbreak, low quarterdeck
Block coefficient: 0.403
Length to Beam Ratio: 9.97 : 1
'Natural speed' for length: 17.00 kts
Power going to wave formation at top speed: 70 %
Trim (Max stability = 0, Max steadiness = 100): 66
Bow angle (Positive = bow angles forward): 24.63 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 24.00 ft / 7.32 m
- Forecastle (20 %): 18.00 ft / 5.49 m
- Mid (50 %): 17.00 ft / 5.18 m (10.00 ft / 3.05 m aft of break)
- Quarterdeck (15 %): 7.00 ft / 2.13 m (10.00 ft / 3.05 m before break)
- Stern: 7.00 ft / 2.13 m
- Average freeboard: 13.88 ft / 4.23 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 186.1 %
- Above water (accommodation/working, high = better): 121.8 %
Waterplane Area: 4,889 Square feet or 454 Square metres
Displacement factor (Displacement / loading): 50 %
Structure weight / hull surface area: 30 lbs/sq ft or 145 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 3.09
- 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