WesWorld

Im planning on reffiting the minesweepers I bought from the SAE. I have two options, which would be better?


1.- Level 3: Major Refits (cost = 15%)
Refurbished to extend life.
4.13" guns replaced with 5" guns
Changes to minesweeping equipment, mine/DC rails added

This ship would serve as a multipurpose light patrol boat. The aft 5" gun would be removed during peacetime.

Maple, Mexico (ex-SAE) Minesweeper laid down 1918

Displacement:
473 t light; 497 t standard; 629 t normal; 735 t full load

Dimensions: Length overall / water x beam x draught
182.00 ft / 182.00 ft x 24.60 ft x 8.20 ft (normal load)
55.47 m / 55.47 m x 7.50 m x 2.50 m

Armament:
2 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1931 Model
Dual purpose guns in deck mounts
on centreline ends, evenly spread
2 - 1.57" / 40.0 mm guns (1x2 guns), 1.95lbs / 0.89kg shells, 1918 Model
Anti-aircraft guns in deck mount
on centreline amidships
4 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1918 Model
Machine guns in deck mounts
on side, evenly spread
Weight of broadside 130 lbs / 59 kg
Shells per gun, main battery: 150

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.00" / 25 mm - -
2nd: 0.50" / 13 mm - -

Machinery:
Coal fired boilers, complex reciprocating steam engines,
Direct drive, 2 shafts, 1,609 ihp / 1,200 Kw = 15.91 kts
Range 6,500nm at 10.00 kts
Bunker at max displacement = 239 tons (100% coal)

Complement:
62 - 81

Cost:
£0.090 million / $0.359 million

Distribution of weights at normal displacement:
Armament: 16 tons, 2.6 %
Armour: 6 tons, 0.9 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 6 tons, 0.9 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 104 tons, 16.6 %
Hull, fittings & equipment: 271 tons, 43.1 %
Fuel, ammunition & stores: 156 tons, 24.8 %
Miscellaneous weights: 75 tons, 11.9 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
962 lbs / 436 Kg = 15.4 x 5.0 " / 127 mm shells or 0.6 torpedoes
Stability (Unstable if below 1.00): 1.22
Metacentric height 0.9 ft / 0.3 m
Roll period: 11.0 seconds
Steadiness - As gun platform (Average = 50 %): 71 %
- Recoil effect (Restricted arc if above 1.00): 0.29
Seaboat quality (Average = 1.00): 1.77

Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.600
Length to Beam Ratio: 7.40 : 1
'Natural speed' for length: 13.49 kts
Power going to wave formation at top speed: 56 %
Trim (Max stability = 0, Max steadiness = 100): 40
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 %): 9.50 ft / 2.90 m
- Mid (50 %): 9.50 ft / 2.90 m
- Quarterdeck (15 %): 9.50 ft / 2.90 m
- Stern: 9.50 ft / 2.90 m
- Average freeboard: 9.94 ft / 3.03 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 87.2 %
- Above water (accommodation/working, high = better): 95.6 %
Waterplane Area: 3,275 Square feet or 304 Square metres
Displacement factor (Displacement / loading): 150 %
Structure weight / hull surface area: 47 lbs/sq ft or 230 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.20
- Longitudinal: 4.54
- Overall: 1.37
Hull space for machinery, storage, compartmentation is adequate
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

***


2.- Level 4: Partial Reconstruction (cost = 25%)
Same as above but with new engines.

Would this be worth it? Is it realistic to increase their speed to 19 kts?

Maple, Mexico (ex-SAE) Minesweeper laid down 1918 (Engine 1932)

Displacement:
558 t light; 582 t standard; 657 t normal; 717 t full load

Dimensions: Length overall / water x beam x draught
190.00 ft / 190.00 ft x 24.60 ft x 8.20 ft (normal load)
57.91 m / 57.91 m x 7.50 m x 2.50 m

Armament:
2 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1931 Model
Dual purpose guns in deck mounts
on centreline ends, evenly spread
2 - 1.57" / 40.0 mm guns (1x2 guns), 1.95lbs / 0.89kg shells, 1918 Model
Anti-aircraft guns in deck mount
on centreline amidships
4 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1918 Model
Machine guns in deck mounts
on side, evenly spread
Weight of broadside 130 lbs / 59 kg
Shells per gun, main battery: 150

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.00" / 25 mm - -
2nd: 0.50" / 13 mm - -

Machinery:
Oil fired boilers, steam turbines,
Direct drive, 2 shafts, 3,343 shp / 2,494 Kw = 19.00 kts
Range 7,500nm at 10.00 kts
Bunker at max displacement = 134 tons

Complement:
64 - 84

Cost:
£0.094 million / $0.376 million

Distribution of weights at normal displacement:
Armament: 16 tons, 2.5 %
Armour: 6 tons, 0.9 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 6 tons, 0.9 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 99 tons, 15.0 %
Hull, fittings & equipment: 387 tons, 58.9 %
Fuel, ammunition & stores: 99 tons, 15.1 %
Miscellaneous weights: 50 tons, 7.6 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
1,125 lbs / 510 Kg = 18.0 x 5.0 " / 127 mm shells or 0.7 torpedoes
Stability (Unstable if below 1.00): 1.12
Metacentric height 0.8 ft / 0.2 m
Roll period: 11.9 seconds
Steadiness - As gun platform (Average = 50 %): 50 %
- Recoil effect (Restricted arc if above 1.00): 0.28
Seaboat quality (Average = 1.00): 1.21

Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.600
Length to Beam Ratio: 7.72 : 1
'Natural speed' for length: 13.78 kts
Power going to wave formation at top speed: 63 %
Trim (Max stability = 0, Max steadiness = 100): 41
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 %): 10.00 ft / 3.05 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: 10.40 ft / 3.17 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 76.8 %
- Above water (accommodation/working, high = better): 101.7 %
Waterplane Area: 3,418 Square feet or 318 Square metres
Displacement factor (Displacement / loading): 171 %
Structure weight / hull surface area: 62 lbs/sq ft or 305 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.53
- Longitudinal: 6.35
- Overall: 1.77
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is adequate
Good seaboat, rides out heavy weather easily

I'm not sure the three knots are worth the cost. Sixteen knots, 6500 nm range, and reciprocating engines might be satisfactory for the basic patrol and minesweeping functions.

Ah! I forgot that. The main reason I was going for the engine change is that Mexico has plenty of oil but not alot of coal and according to the rules I would have to do a Partial Reconstruction to change the ship from coal to oil.

Did Mexico know about its oil in the 1930s? I thought they just discovered in the 1970s.

Actually in 1930 Mexico was one of the 3 top oil exporters (I think the other 2 where US and DEI) in the world. There where some problems due to it in 1938 and some important newshere in WW will be related to oil.

I would not bother with the additional speed. I don't think that there many things you could catch at the higher that you could not at the lower. The oil/coal firing is more of a problem.

Mexico apparently does have coal, just low quality. According to http://www.cslforum.org/mexico.htm in the 1990s Mexico was a bituminous coal producer.
http://www.methanetomarkets.org/events/2…docs/mexico.pdf
indicates that it was first mined in 1850 but it sounds like it wasn't heavily exploited.

I don't know the extent of the holdings, but as early as 1919 there was Mexican Oil companies, as Royal Dutch Shell aquired one then
- From wikipedia : In 1919, Shell took control of the Mexican Eagle Petroleum Company and in 1921 formed Shell-Mex Limited which marketed products under the “Shell” and “Eagle” brands in the United Kingdom.

If you're replacing the engines, I'd give serious thought to diesels...