WesWorld

...and from the odd-ball files:

A concern with disaster relief efforts these days is what happens to a major coastal town or city which is cut off from the electrical grid or has its local power source severely damaged. The answer is to have a diesel powerplant on a barge, ready to be towed to the stricken location. The barge would be anchored close ashore or tied up at an intact pier, and then weather-resistent cables would be run ashore and spliced into the local power grid, such as it was.

This particular barge, built to civilian standards, has four 2,500 KW diesel generators, with fuel to supply ten days of full operation. This will not restore full power to a large city, but should fully light up a smaller community of several thousand or allow key services such as hospitals to function in larger communities.

As a reference point, the modern community of Iqaluit, Nunavut (6,700 people) has a max capacity of 15.1 MW; one expects a similar-sized community of the 1940s to have substantially less need.

Obviously, you should ignore the speed/seakeeping figures - the machinery is there to represent the powerplant. The barge is unpowered, but its freeboard should keep it plenty dry. At fifteen knots, its seakeeping value is around 1.75.

Enter ship name, Enter country Enter ship type laid down 1944

Displacement:
1,315 t light; 1,362 t standard; 2,334 t normal; 3,112 t full load

Dimensions: Length overall / water x beam x draught
233.65 ft / 223.10 ft x 59.06 ft x 8.86 ft (normal load)
71.22 m / 68.00 m x 18.00 m x 2.70 m

Machinery:
Diesel Internal combustion generators,
Electric motors, 0 shafts, 13,405 shp / 10,000 Kw = 22.44 kts
Range 5,390nm at 22.44 kts
Bunker at max displacement = 1,750 tons
Caution: Too much power for number of propellor shafts

Complement:
167 - 218

Cost:
£0.632 million / $2.528 million

Distribution of weights at normal displacement:
Armament: 0 tons, 0.0 %
Machinery: 342 tons, 14.7 %
Hull, fittings & equipment: 870 tons, 37.3 %
Fuel, ammunition & stores: 1,019 tons, 43.7 %
Miscellaneous weights: 103 tons, 4.4 %
-50 t: Ship to shore cabling, winch, reel, etc.
-50 t: Towing gear
-3 t: Weight reserve

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
9,074 lbs / 4,116 Kg = 84.0 x 6 " / 152 mm shells or 2.3 torpedoes
Stability (Unstable if below 1.00): 1.31
Metacentric height 3.7 ft / 1.1 m
Roll period: 12.9 seconds
Steadiness - As gun platform (Average = 50 %): 50 %
- Recoil effect (Restricted arc if above 1.00): 0.00
Seaboat quality (Average = 1.00): 0.69

Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.700
Length to Beam Ratio: 3.78 : 1
'Natural speed' for length: 18.23 kts
Power going to wave formation at top speed: 74 %
Trim (Max stability = 0, Max steadiness = 100): 73
Bow angle (Positive = bow angles forward): 10.00 degrees
Stern overhang: 6.56 ft / 2.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 22.64 ft / 6.90 m
- Forecastle (20 %): 19.69 ft / 6.00 m
- Mid (50 %): 19.69 ft / 6.00 m
- Quarterdeck (15 %): 19.69 ft / 6.00 m
- Stern: 19.69 ft / 6.00 m
- Average freeboard: 19.92 ft / 6.07 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 53.6 %
- Above water (accommodation/working, high = better): 247.6 %
Waterplane Area: 11,028 Square feet or 1,025 Square metres
Displacement factor (Displacement / loading): 296 %
Structure weight / hull surface area: 60 lbs/sq ft or 292 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.83
- Longitudinal: 5.36
- Overall: 1.00
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
Caution: Lacks seaworthiness - very limited seakeeping ability

Warning: Too much power for number of propellor shafts

There's precedent. In 1929 the USS Lexington provided 1/4 of the power for the city of Tacoma.

Tacoma

I suppose if you lack turbo-electric drive in the fleet, the barge is a good answer. You can retrofit a civilian one.

That incident was the inspiration for the barge. So far as I know, neither I nor Perds put turbo-electric into any Bharati ships...

Quoted

Originally posted by The Rock Doctor
That incident was the inspiration for the barge. So far as I know, neither I nor Perds put turbo-electric into any Bharati ships...

One of the reasons behind the Kriegsmarine's choice for the mercantile hulls converted to the two Coronel class advanced base ship was the ability to draw power from the turbo-electric engines if the need arose. Costly in some respects, but useful.

I've made most Dutch ships Turbo-electric both for flavor and I like the idea. To me the real life tradeoff of the loss of a knot in exchange for better manueverabilty, fuel efficiency and damage control (SoDak's bridged fuses not withstanding) seems worthwhile.

Should there ever be a reboot, I'd like to see modifiers for Turbo-electric and Diesel engines.

Something like TE gives x91% SHP and x110% range and Diesel gives x75% SHP and x150% range. Those numbers are from vague recollections, but I think they are "ballpark". Though I've got one source that places the TE penalty higher in weight, and dings the efficiency, that doesn't match the original USN comparisons.

An example would be a van Heemskerk designed for the wartime unrefueled passage around Scotland and Cape Hope to Batavia, with a reserve... still only 16% fuel and stores. She's geared as it didn't matter, but with Turbo-electric, she would make 28.2933knts instead of 29knts, but range could be dropped to 15136.36, gaining 0.3 comp hull which could have gone to armor, or a smaller ship...or to bring the SHP back up..

Perhaps I'll give this some thought for any future disaster-relief ships that come along.