A development of the Multi Purpose Ship, made with the intent of reducing cost even further. While this ship can still be turned into an ad hoc minelayer/sweeper, it no longer has the full capability. It also doesnt have the full quick change capability. Only the rear gun (40mm->4") and the two foward fixed torpedo tubes (18"TT->40mm) can be exchanged. She can also use 76mm army field guns in emergencies.
100 of these will be built and only 50 Multi Purpose (down from 120)
PT-1 , New Switzerland Patrol Torpedo Boat laid down 1907 (Engine 1909)
Displacement:
191 t light; 201 t standard; 226 t normal; 246 t full load
Dimensions: Length overall / water x beam x draught
194.73 ft / 190.00 ft x 19.00 ft x 5.10 ft (normal load)
59.35 m / 57.91 m x 5.79 m x 1.55 m
Armament:
1 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1907 Model
Quick firing gun in deck mount
on centreline forward
2 - 1.57" / 40.0 mm guns (1x2 guns), 1.95lbs / 0.89kg shells, 1907 Model
Quick firing guns in deck mount
on centreline aft
2 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1907 Model
Machine guns in deck mounts
on side, evenly spread
Weight of broadside 36 lbs / 16 kg
Shells per gun, main battery: 270
4 - 18.0" / 457.2 mm above water torpedoes
Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.50" / 13 mm - -
Machinery:
Coal and oil fired boilers, steam turbines,
Direct drive, 2 shafts, 3,991 shp / 2,977 Kw = 24.00 kts
Range 2,000nm at 10.00 kts
Bunker at max displacement = 45 tons (90% coal)
Complement:
28 - 37
Cost:
£0.026 million / $0.104 million
Distribution of weights at normal displacement:
Armament: 5 tons, 2.0 %
Armour: 1 tons, 0.5 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 1 tons, 0.5 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 111 tons, 48.9 %
Hull, fittings & equipment: 69 tons, 30.7 %
Fuel, ammunition & stores: 36 tons, 15.7 %
Miscellaneous weights: 5 tons, 2.2 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
74 lbs / 33 Kg = 2.3 x 4.0 " / 102 mm shells or 0.1 torpedoes
Stability (Unstable if below 1.00): 1.25
Metacentric height 0.6 ft / 0.2 m
Roll period: 10.2 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.20
Seaboat quality (Average = 1.00): 1.01
Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.430
Length to Beam Ratio: 10.00 : 1
'Natural speed' for length: 13.78 kts
Power going to wave formation at top speed: 65 %
Trim (Max stability = 0, Max steadiness = 100): 69
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 13.00 ft / 3.96 m
- Forecastle (20 %): 9.00 ft / 2.74 m
- Mid (40 %): 8.00 ft / 2.44 m
- Quarterdeck (20 %): 7.00 ft / 2.13 m
- Stern: 7.00 ft / 2.13 m
- Average freeboard: 8.22 ft / 2.51 m
Ship tends to be wet forward
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 176.8 %
- Above water (accommodation/working, high = better): 53.0 %
Waterplane Area: 2,267 Square feet or 211 Square metres
Displacement factor (Displacement / loading): 52 %
Structure weight / hull surface area: 16 lbs/sq ft or 80 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 1.74
- Overall: 0.56
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
I'm not really keen on the whole weapon/kit swapping concept, really, but I suppose it's a decent coastal defence vessel.