ARA General San Martin
Rebuilt ex-Brazilian Margay Class destroyer brought in 1942.
Project 451C (ex-Margay Class), Brazil School Ship (Argentine Refit 1942) laid down 1932 (Engine 1942)
Displacement:
2,118 t light; 2,204 t standard; 2,602 t normal; 2,919 t full load
Dimensions: Length overall / water x beam x draught
401.26 ft / 390.00 ft x 40.00 ft x 13.00 ft (normal load)
122.30 m / 118.87 m x 12.19 m x 3.96 m
Armament:
2 - 5.12" / 130 mm guns (1x2 guns), 70.55lbs / 32.00kg shells, 1937 Model
Dual purpose guns in a deck mount with hoist
on centreline forward
2 - 4.53" / 115 mm guns (1x2 guns), 55.12lbs / 25.00kg shells, 1937 Model
Dual purpose guns in a deck mount with hoist
on centreline forward, all raised guns - superfiring
12 - 1.46" / 37.0 mm guns (6x2 guns), 1.55lbs / 0.70kg shells, 1937 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
4 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1937 Model
Anti-aircraft guns in deck mounts
on side, all amidships, all raised mounts - superfiring
Weight of broadside 271 lbs / 123 kg
Shells per gun, main battery: 200
4 - 21.0" / 533.4 mm above water torpedoes
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 1.00" / 25 mm 390.00 ft / 118.87 m 8.00 ft / 2.44 m
Ends: Unarmoured
Main Belt covers 154 % of normal length
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.97" / 50 mm 0.98" / 25 mm 2.00" / 51 mm
2nd: 1.97" / 50 mm 0.98" / 25 mm 2.00" / 51 mm
3rd: 0.39" / 10 mm - -
4th: 0.39" / 10 mm - -
- Armour deck: 0.25" / 6 mm
Machinery:
Oil fired boilers, steam turbines plus diesel motors,
Geared drive, 3 shafts, 40,000 shp / 29,840 Kw = 31.39 kts
Range 13,000nm at 12.00 kts
Bunker at max displacement = 715 tons
Complement:
181 - 236
Cost:
£1.108 million / $4.432 million
Distribution of weights at normal displacement:
Armament: 31 tons, 1.2 %
Armour: 181 tons, 7.0 %
- Belts: 115 tons, 4.4 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 19 tons, 0.7 %
- Armour Deck: 46 tons, 1.8 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 1,027 tons, 39.5 %
Hull, fittings & equipment: 699 tons, 26.9 %
Fuel, ammunition & stores: 484 tons, 18.6 %
Miscellaneous weights: 180 tons, 6.9 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
1,065 lbs / 483 Kg = 15.9 x 5.1 " / 130 mm shells or 0.5 torpedoes
Stability (Unstable if below 1.00): 1.26
Metacentric height 1.9 ft / 0.6 m
Roll period: 12.1 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.31
Seaboat quality (Average = 1.00): 1.20
Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.449
Length to Beam Ratio: 9.75 : 1
'Natural speed' for length: 19.75 kts
Power going to wave formation at top speed: 63 %
Trim (Max stability = 0, Max steadiness = 100): 58
Bow angle (Positive = bow angles forward): 25.00 degrees
Stern overhang: 1.00 ft / 0.30 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 22.00 ft / 6.71 m
- Forecastle (20 %): 16.00 ft / 4.88 m
- Mid (50 %): 16.00 ft / 4.88 m
- Quarterdeck (15 %): 16.00 ft / 4.88 m
- Stern: 16.00 ft / 4.88 m
- Average freeboard: 16.48 ft / 5.02 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 144.9 %
- Above water (accommodation/working, high = better): 137.8 %
Waterplane Area: 9,943 Square feet or 924 Square metres
Displacement factor (Displacement / loading): 96 %
Structure weight / hull surface area: 38 lbs/sq ft or 184 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 1.59
- Overall: 0.56
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
Good seaboat, rides out heavy weather easily
Refit Changes
120mm mounts replaced by one 130mm Mk III DP mount and one 115mm Mk III DP mount
Removal of upper torpedo tube mount
Removal of Z mount
New main director
Addition of RDF
Addition of new boilers and tubines
Addition of 1,000hp diesel engine to drive third shaft (max speed 11 kts on diesel
New deckhouse aft with accomodation for 50 cadets and classroom
Landing spot abve deckhouse
Refurbishment of internal fittings
Misc Weight Breakdown
9 tons for one quad torpedo mount and four torpedoes
15 tons RDF
100 tons for accomodation for 50 cadets
26 tons for diesel and gearbox
25 tons for strengthened deck for landing spot
5 tons for classroom spaces