WesWorld

Preposed refit for 1919 P-class Patrol Boats



Orriginal configuration
E-class Patrol Boats 1919 (Now P-class)
*now classed as escorts*

P-1 through P-51 (50 ships)

Atlantean Patrol vessels laid down 1919

Displacement:
445 t light; 467 t standard; 523 t normal; 567 t full load

Dimensions: Length overall / water x beam x draught
201.05 ft / 200.00 ft x 25.00 ft x 7.32 ft (normal load)
61.28 m / 60.96 m x 7.62 m x 2.23 m

Armament:
2 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1919 Model
Breech loading guns in deck mounts
on centreline ends, evenly spread
2 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1919 Model
Anti-aircraft guns in deck mounts
on centreline ends, evenly spread, all raised mounts
4 - 1.00" / 25.4 mm guns in single mounts, 0.50lbs / 0.23kg shells, 1919 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 93 lbs / 42 kg
Shells per gun, main battery: 200

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 1 shaft, 2,153 shp / 1,606 Kw = 18.00 kts
Range 3,500nm at 12.00 kts
Bunker at max displacement = 100 tons

Complement:
54 - 71

Cost:
£0.079 million / $0.315 million

Distribution of weights at normal displacement:
Armament: 12 tons, 2.2 %
Machinery: 76 tons, 14.6 %
Hull, fittings & equipment: 342 tons, 65.5 %
Fuel, ammunition & stores: 77 tons, 14.8 %
Miscellaneous weights: 15 tons, 2.9 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
1,054 lbs / 478 Kg = 32.9 x 4.0 " / 102 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 %): 71 %
- Recoil effect (Restricted arc if above 1.00): 0.25
Seaboat quality (Average = 1.00): 1.45

Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.500
Length to Beam Ratio: 8.00 : 1
'Natural speed' for length: 14.14 kts
Power going to wave formation at top speed: 55 %
Trim (Max stability = 0, Max steadiness = 100): 49
Bow angle (Positive = bow angles forward): 5.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 12.00 ft / 3.66 m
- Forecastle (20 %): 9.50 ft / 2.90 m
- Mid (50 %): 9.50 ft / 2.90 m
- Quarterdeck (15 %): 9.00 ft / 2.74 m
- Stern: 9.00 ft / 2.74 m
- Average freeboard: 9.54 ft / 2.91 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 69.3 %
- Above water (accommodation/working, high = better): 105.8 %
Waterplane Area: 3,202 Square feet or 297 Square metres
Displacement factor (Displacement / loading): 200 %
Structure weight / hull surface area: 61 lbs/sq ft or 298 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.57
- Longitudinal: 4.61
- Overall: 1.75
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
Good seaboat, rides out heavy weather easily

Refited version now with uniform DP armament of 3.95" DP mounts.
Refit also includes a remodeling of the bridge structure, a new verticle funnel and new 40mm, 20mm and 12.7mm weapons.
Basic mine sweeping gear has been removed and DC complement has been increased. Sonar has also been added.
The orriginal machinery is retained and refurbished.
They still retain their distinctive steped apearance forward and gently sloping deck

E-class (Now P-class) *now classed as escorts*
Atlantean Patrol vessels laid down 1919, refited 1932

Displacement:
435 t light; 460 t standard; 523 t normal; 573 t full load

Dimensions: Length overall / water x beam x draught
201.05 ft / 200.00 ft x 25.00 ft x 7.32 ft (normal load)
61.28 m / 60.96 m x 7.62 m x 2.23 m

Armament:
3 - 3.95" / 100 mm guns in single mounts, 30.81lbs / 13.98kg shells, 1932 Model
Dual purpose guns in deck mounts
on centreline ends, majority forward
2 - 1.57" / 39.9 mm guns (1x2 guns), 1.93lbs / 0.88kg shells, 1932 Model
Anti-aircraft guns in deck mount
on centreline forward, all raised guns
4 - 0.79" / 20.0 mm guns (2x2 guns), 0.24lbs / 0.11kg shells, 1932 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
2 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1932 Model
Machine guns in deck mounts
on side, evenly spread
Weight of broadside 97 lbs / 44 kg
Shells per gun, main battery: 250

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 1 shaft, 2,153 shp / 1,606 Kw = 18.00 kts
Range 4,000nm at 12.00 kts
Bunker at max displacement = 113 tons

Complement:
54 - 71

Cost:
£0.079 million / $0.316 million

Distribution of weights at normal displacement:
Armament: 12 tons, 2.3 %
Machinery: 76 tons, 14.6 %
Hull, fittings & equipment: 317 tons, 60.6 %
Fuel, ammunition & stores: 87 tons, 16.7 %
Miscellaneous weights: 30 tons, 5.7 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
999 lbs / 453 Kg = 32.4 x 4.0 " / 100 mm shells or 0.7 torpedoes
Stability (Unstable if below 1.00): 1.14
Metacentric height 0.8 ft / 0.2 m
Roll period: 11.8 seconds
Steadiness - As gun platform (Average = 50 %): 71 %
- Recoil effect (Restricted arc if above 1.00): 0.24
Seaboat quality (Average = 1.00): 1.47

Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.500
Length to Beam Ratio: 8.00 : 1
'Natural speed' for length: 14.14 kts
Power going to wave formation at top speed: 55 %
Trim (Max stability = 0, Max steadiness = 100): 48
Bow angle (Positive = bow angles forward): 5.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 12.00 ft / 3.66 m
- Forecastle (20 %): 9.50 ft / 2.90 m
- Mid (50 %): 9.50 ft / 2.90 m
- Quarterdeck (15 %): 9.00 ft / 2.74 m
- Stern: 9.00 ft / 2.74 m
- Average freeboard: 9.54 ft / 2.91 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 73.6 %
- Above water (accommodation/working, high = better): 105.8 %
Waterplane Area: 3,202 Square feet or 297 Square metres
Displacement factor (Displacement / loading): 187 %
Structure weight / hull surface area: 56 lbs/sq ft or 276 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.46
- Longitudinal: 4.28
- Overall: 1.63
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
Good seaboat, rides out heavy weather easily