DM-1-class, Chilean Minesweeper laid down 1935, Refit 1948
A general-purpose minesweeper and patrol ship, used for coastal purposes. As refitted 1948.
Displacement:
425 t light; 440 t standard; 528 t normal; 599 t full load
Dimensions: Length overall / water x beam x draught
190.00 ft / 190.00 ft x 24.00 ft x 8.00 ft (normal load)
57.91 m / 57.91 m x 7.32 m x 2.44 m
Armament:
2 - 2.95" / 75.0 mm guns in single mounts, 13.23lbs / 6.00kg shells, 1948 Model
Dual purpose guns in deck mounts with hoists
on centreline ends, evenly spread
2 - 1.57" / 40.0 mm guns (1x2 guns), 1.95lbs / 0.89kg shells, 1948 Model
Anti-aircraft guns in deck mount
on centreline forward, all raised guns - superfiring
2 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1935 Model
Machine guns in deck mounts
on side, evenly spread
Weight of broadside 30 lbs / 14 kg
Shells per gun, main battery: 210
Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.79" / 20 mm 0.59" / 15 mm 0.59" / 15 mm
2nd: 0.59" / 15 mm - -
- Conning tower: 0.79" / 20 mm
Machinery:
Diesel Internal combustion motors,
Geared drive, 2 shafts, 1,385 shp / 1,033 Kw = 16.00 kts
Range 5,500nm at 13.00 kts
Bunker at max displacement = 160 tons
Complement:
54 - 71
Cost:
£0.120 million / $0.479 million
Distribution of weights at normal displacement:
Armament: 4 tons, 0.7 %
Armour: 4 tons, 0.8 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 3 tons, 0.6 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 1 tons, 0.2 %
Machinery: 39 tons, 7.4 %
Hull, fittings & equipment: 248 tons, 46.9 %
Fuel, ammunition & stores: 103 tons, 19.5 %
Miscellaneous weights: 130 tons, 24.6 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
1,284 lbs / 583 Kg = 99.8 x 3.0 " / 75 mm shells or 0.9 torpedoes
Stability (Unstable if below 1.00): 1.08
Metacentric height 0.7 ft / 0.2 m
Roll period: 12.2 seconds
Steadiness - As gun platform (Average = 50 %): 50 %
- Recoil effect (Restricted arc if above 1.00): 0.16
Seaboat quality (Average = 1.00): 2.00
Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.507
Length to Beam Ratio: 7.92 : 1
'Natural speed' for length: 13.78 kts
Power going to wave formation at top speed: 51 %
Trim (Max stability = 0, Max steadiness = 100): 25
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: 15.50 ft / 4.72 m
- Forecastle (20 %): 11.00 ft / 3.35 m
- Mid (50 %): 10.00 ft / 3.05 m
- Quarterdeck (15 %): 10.00 ft / 3.05 m
- Stern: 10.00 ft / 3.05 m
- Average freeboard: 10.71 ft / 3.26 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 57.6 %
- Above water (accommodation/working, high = better): 110.3 %
Waterplane Area: 3,058 Square feet or 284 Square metres
Displacement factor (Displacement / loading): 218 %
Structure weight / hull surface area: 41 lbs/sq ft or 202 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.07
- Longitudinal: 5.44
- Overall: 1.26
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is adequate
Excellent seaboat, comfortable, can fire her guns in the heaviest weather
Breakdown of Miscellaneous Weights:
- 9 tons for Kodkod launchers (with 64 reloads)
- 15 tons for Suite-48 electronics
- 6 tons for depth charges (28x420-lb bombs)
- 55 tons for minesweeping gear
- 10 tons for heating / air conditioning system
- 35 tons for miscellaneous gear
Suite-48 Electronics:
- Type 103.1 "Nalca" navigational surface and air search radar (1 radar, 2 tons)
- Sisdef SPR-48P Passive (Rochelle Salt) Hydrophones (1 primary, 1 secondary, 5 tons)
- Sisdef SPR-48A Active Hydrophones (2 primary, 2 secondary, 5 tons)
- Roth-389b backup diesel generator set (3 tons)
Change log:
- Radar added
- Sonar updated
- 37mm AA replaced with 40mm AA
- 76.2mm deck gun replaced with 75mm deck gun
- Kodkod added
- Excess miscellaneous weight dropped to improve stability.
Refitted 1948 for 64t each.
*****
DM1935 Dragaminas, Chile Minesweeper laid down 1935
Displacement:
425 t light; 440 t standard; 528 t normal; 599 t full load
Dimensions: Length overall / water x beam x draught
190.00 ft / 190.00 ft x 24.00 ft x 8.00 ft (normal load)
57.91 m / 57.91 m x 7.32 m x 2.44 m
Armament:
2 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1935 Model
Dual purpose guns in deck mounts with hoists
on centreline ends, evenly spread
2 - 1.46" / 37.0 mm guns (1x2 guns), 1.55lbs / 0.70kg shells, 1935 Model
Anti-aircraft guns in deck mount
on centreline forward, all raised guns - superfiring
2 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1935 Model
Machine guns in deck mounts
on side, all amidships
Weight of broadside 30 lbs / 14 kg
Shells per gun, main battery: 210
Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.79" / 20 mm 0.59" / 15 mm 0.59" / 15 mm
2nd: 0.59" / 15 mm - -
- Conning tower: 0.79" / 20 mm
Machinery:
Diesel Internal combustion motors,
Geared drive, 2 shafts, 1,385 shp / 1,033 Kw = 16.00 kts
Range 5,500nm at 13.00 kts
Bunker at max displacement = 160 tons
Complement:
54 - 71
Cost:
£0.120 million / $0.480 million
Distribution of weights at normal displacement:
Armament: 4 tons, 0.7 %
Armour: 4 tons, 0.8 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 3 tons, 0.6 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 1 tons, 0.2 %
Machinery: 39 tons, 7.4 %
Hull, fittings & equipment: 199 tons, 37.7 %
Fuel, ammunition & stores: 103 tons, 19.5 %
Miscellaneous weights: 179 tons, 33.9 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
1,082 lbs / 491 Kg = 80.1 x 3.0 " / 76 mm shells or 0.8 torpedoes
Stability (Unstable if below 1.00): 1.06
Metacentric height 0.7 ft / 0.2 m
Roll period: 12.5 seconds
Steadiness - As gun platform (Average = 50 %): 50 %
- Recoil effect (Restricted arc if above 1.00): 0.16
Seaboat quality (Average = 1.00): 2.00
Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.507
Length to Beam Ratio: 7.92 : 1
'Natural speed' for length: 13.78 kts
Power going to wave formation at top speed: 51 %
Trim (Max stability = 0, Max steadiness = 100): 25
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: 15.50 ft / 4.72 m
- Forecastle (20 %): 11.00 ft / 3.35 m
- Mid (50 %): 10.00 ft / 3.05 m
- Quarterdeck (15 %): 10.00 ft / 3.05 m
- Stern: 10.00 ft / 3.05 m
- Average freeboard: 10.71 ft / 3.26 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 67.6 %
- Above water (accommodation/working, high = better): 110.3 %
Waterplane Area: 3,058 Square feet or 284 Square metres
Displacement factor (Displacement / loading): 181 %
Structure weight / hull surface area: 33 lbs/sq ft or 162 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.86
- Longitudinal: 4.35
- Overall: 1.01
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is adequate
Excellent seaboat, comfortable, can fire her guns in the heaviest weather
Ships in Class (DM1935):
-
DM-1: In service
-
DM-2: In service
-
DM-3: In service
-
DM-4: In service
-
DM-5: In service
-
DM-6: In service
-
DM-7: In service
-
DM-8: In service
-
DM-9: In service
-
DM-10: In service
-
DM-11: In service
-
DM-12: In service
Ships in Class (DM1935/38):
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DM-13: In service
-
DM-14: In service
-
DM-15: In service
-
DM-16: In service