WesWorld

Persia is issuing a RfP for Merchant ships suitable for conversion into Fleet Replenishment Ships capable of carrying at least 2000 tons of oil and 1000 tons of other stores.

Maximum/cruising speeds?

A cruising speed of 12-15kts would be nice (and yes I know this is high)

For an ship capable of replenishing underway I'm not sure a converted merchant vessel is good enough, especially for oiling.

Well that seems to be the most popular way in WW and its cheaper....

I think there's a big difference between some sort of vessel that can carry stores and something capable of proper underway replenishment.

Probably depends on what you're passing. This site talks about WWI UNREP operations (fuel, rather than ammunition): http://www.globalsecurity.org/military/l…rt/1989/HDD.htm . Doesn't sound like there's huge amounts of tackle involved, actually: a cargo boom, a 4" fuel line, fuel pumps, etc. Fuel, apparently, was the limit of UNREP during the period.

You'd probably be better off building something like a bigger version of the LE Meath:



Which reminds me I forgot to add her to my encyclopedia.

It would have to be a lot bigger and more expensive... Rebuilding an existing ship is both faster and cheaper

But, IMHO, not necessarily better.

What do you intend to use this vessel to do? Support a DD squadron? Support the little carrier, or the cruiser? Both?

Looking at historical ships for this they don't seem to be arranged like normal merchant ships and have considerably more deck tackle. A couple of examples here. I've a 1950s book on ships with lots of pictures and drawings of merchants, I'll try and scan some tomorrow.

Quoted

Originally posted by Brockpaine
But, IMHO, not necessarily better.

What do you intend to use this vessel to do? Support a DD squadron? Support the little carrier, or the cruiser? Both?

Both DD Squadron and the Heavy squadron (BC/CVE)

Oil and supplies, or just oil, or just supplies? Meath is just supplies. I don't put oil and supplies on the same ship, I build two ships instead.

-------------------------

Also, I had this larger version of Meath under Bulgarian consideration. I have her scheduled for 1938, in fact.


[SIZE=1]Image originally by wes/thesmilingassassin and heavily modified by me.[/SIZE]

[SIZE=3]Stara Planina-class, Bulgarian Fleet Tender laid down 1938[/SIZE]

Displacement:
3,000 t light; 3,099 t standard; 3,564 t normal; 3,936 t full load

Dimensions: Length overall / water x beam x draught
351.92 ft / 344.49 ft x 47.57 ft x 14.27 ft (normal load)
107.26 m / 105.00 m x 14.50 m x 4.35 m

Armament:
4 - 3.94" / 100 mm guns (2x2 guns), 30.51lbs / 13.84kg shells, 1938 Model
Dual purpose guns in deck mounts with hoists
on centreline ends, evenly spread
6 - 1.57" / 40.0 mm guns (2x3 guns), 1.95lbs / 0.89kg shells, 1938 Model
Dual purpose guns in deck mounts with hoists
on side, all amidships, all raised mounts - superfiring
8 - 1.57" / 40.0 mm guns (4x2 guns), 1.95lbs / 0.89kg shells, 1938 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
2 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1938 Model
Machine guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 150 lbs / 68 kg
Shells per gun, main battery: 300

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.98" / 25 mm 0.79" / 20 mm 0.79" / 20 mm
2nd: 0.79" / 20 mm - -

- Armour deck: 0.79" / 20 mm, Conning tower: 2.00" / 51 mm

Machinery:
Diesel Internal combustion motors,
Geared drive, 2 shafts, 15,634 shp / 11,663 Kw = 23.00 kts
Range 7,000nm at 15.00 kts
Bunker at max displacement = 836 tons

Complement:
229 - 299

Cost:
£1.018 million / $4.073 million

Distribution of weights at normal displacement:
Armament: 19 tons, 0.5 %
Armour: 185 tons, 5.2 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 11 tons, 0.3 %
- Armour Deck: 164 tons, 4.6 %
- Conning Tower: 10 tons, 0.3 %
Machinery: 428 tons, 12.0 %
Hull, fittings & equipment: 1,068 tons, 30.0 %
Fuel, ammunition & stores: 564 tons, 15.8 %
Miscellaneous weights: 1,300 tons, 36.5 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
4,801 lbs / 2,177 Kg = 157.3 x 3.9 " / 100 mm shells or 1.2 torpedoes
Stability (Unstable if below 1.00): 1.05
Metacentric height 1.8 ft / 0.6 m
Roll period: 14.8 seconds
Steadiness - As gun platform (Average = 50 %): 50 %
- Recoil effect (Restricted arc if above 1.00): 0.07
Seaboat quality (Average = 1.00): 1.14

Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0.533
Length to Beam Ratio: 7.24 : 1
'Natural speed' for length: 18.56 kts
Power going to wave formation at top speed: 58 %
Trim (Max stability = 0, Max steadiness = 100): 44
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: 20.41 ft / 6.22 m
- Forecastle (20 %): 17.22 ft / 5.25 m
- Mid (50 %): 17.22 ft / 5.25 m (9.84 ft / 3.00 m aft of break)
- Quarterdeck (15 %): 9.84 ft / 3.00 m
- Stern: 9.84 ft / 3.00 m
- Average freeboard: 13.79 ft / 4.20 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 83.7 %
- Above water (accommodation/working, high = better): 124.1 %
Waterplane Area: 11,260 Square feet or 1,046 Square metres
Displacement factor (Displacement / loading): 143 %
Structure weight / hull surface area: 63 lbs/sq ft or 308 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.95
- Longitudinal: 1.67
- Overall: 1.00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent

I like the Chinese Xiangtan class but I am not prepared to invest that much tonnage, if I on the other hand could find a nice banana bot or tanker to rebuild (25 or 50%)....

How much are you willing to invest, then?

2-3000 tons/ship

*Bulgaria hat*

Speaking as another three-factory power, it's my opinion that I'd rather build two 3000-ton support ships than one 6,000-ton support ship; and me being... me, I'd rather build a new ship to do the job, hence why Ireland's building Meath and Bulgaria will eventually be building Stara Planina (and probably some sisters, too).

That said, if you want a ship you can put into service with a 25% refit for 2kt-3kt...

Quoted

Enter ship name, Enter country Enter ship type laid down 1937

Displacement:
8,500 t light; 8,752 t standard; 11,030 t normal; 12,853 t full load

Dimensions: Length overall / water x beam x draught
550.00 ft / 550.00 ft x 72.00 ft x 18.00 ft (normal load)
167.64 m / 167.64 m x 21.95 m x 5.49 m

Armament:
4 - 5.12" / 130 mm guns (2x2 guns), 67.03lbs / 30.41kg shells, 1937 Model
Dual purpose guns in deck mounts with hoists
on centreline ends, evenly spread
4 - 1.57" / 40.0 mm guns (2x2 guns), 1.95lbs / 0.89kg shells, 1937 Model
Anti-aircraft guns in deck mounts
on side, all amidships
4 - 0.52" / 13.2 mm guns in single mounts, 0.07lbs / 0.03kg shells, 1937 Model
Machine guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 276 lbs / 125 kg
Shells per gun, main battery: 200

Machinery:
Diesel Internal combustion motors,
Geared drive, 2 shafts, 8,050 shp / 6,006 Kw = 16.50 kts
Range 25,000nm at 13.00 kts
Bunker at max displacement = 4,101 tons

Complement:
537 - 699

Cost:
£1.951 million / $7.805 million

Distribution of weights at normal displacement:
Armament: 35 tons, 0.3 %
Machinery: 223 tons, 2.0 %
Hull, fittings & equipment: 5,242 tons, 47.5 %
Fuel, ammunition & stores: 2,530 tons, 22.9 %
Miscellaneous weights: 3,000 tons, 27.2 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
32,409 lbs / 14,701 Kg = 483.5 x 5.1 " / 130 mm shells or 5.3 torpedoes
Stability (Unstable if below 1.00): 1.17
Metacentric height 4.1 ft / 1.3 m
Roll period: 14.9 seconds
Steadiness - As gun platform (Average = 50 %): 71 %
- Recoil effect (Restricted arc if above 1.00): 0.03
Seaboat quality (Average = 1.00): 1.50

Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.542
Length to Beam Ratio: 7.64 : 1
'Natural speed' for length: 23.45 kts
Power going to wave formation at top speed: 28 %
Trim (Max stability = 0, Max steadiness = 100): 47
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: 25.80 ft / 7.86 m
- Forecastle (20 %): 16.42 ft / 5.00 m
- Mid (50 %): 16.42 ft / 5.00 m
- Quarterdeck (15 %): 16.42 ft / 5.00 m
- Stern: 16.42 ft / 5.00 m
- Average freeboard: 17.17 ft / 5.23 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 40.0 %
- Above water (accommodation/working, high = better): 159.7 %
Waterplane Area: 27,420 Square feet or 2,547 Square metres
Displacement factor (Displacement / loading): 296 %
Structure weight / hull surface area: 139 lbs/sq ft or 678 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.61
- Longitudinal: 1.65
- Overall: 1.61
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable, can fire her guns in the heaviest weather

2,125 tons to refit at 25% rebuild (for guns and various deck-clutter ie. cranes)

Looks good, what ship is it based on?

Quoted

Originally posted by Vukovlad
Looks good, what ship is it based on?

Not based on anything but the numbers in my head. Merchantmen are fat and deep-drafting, and most of the 1930s-1940s merchantmen I've seen tend to run in the 400-550ft length, so I just took a general stab at dimensions. 16.5 knots is about what that Chinese ship runs, so I set that as top speed, and you use 13cm and 4cm guns. In truth I'd expect she could go to an 80-foot beam and 24-foot draft and still be realistic to the period merchantmen.

Adding that massive range is good for stability, and you can probably block off, say, half of the tanks for straight oil rather than diesel, and count that as your refueling bunkerage.

As I said, I'm not entirely shiny on the concept of merging oiler and tender - I think you'd be better with an actual purpose-built ship for that - but a comprehensive rebuild could convert an oiler's bunkerage into some cargo storage.

Also, she's a bit similar to Karaboudjan, though shorter and shallower. Karaboudjan picks up a high speed but I tanked her hull strength down to 1.01, with negative effects on stability and steadiness. And Karaboudjan is a comboliner, so she would have been built to a higher construction standard than a ship like you want.

Quoted

Karaboudjan, Pirate AMC laid down 1931

Displacement:
10,774 t light; 11,100 t standard; 13,551 t normal; 15,511 t full load

Dimensions: Length overall / water x beam x draught
582.36 ft / 580.00 ft x 72.00 ft x 20.50 ft (normal load)
177.50 m / 176.78 m x 21.95 m x 6.25 m

Armament:
6 - 6.00" / 152 mm guns in single mounts, 108.00lbs / 48.99kg shells, 1931 Model
Breech loading guns in deck mounts
on centreline ends, evenly spread
4 - 1.46" / 37.0 mm guns in single mounts, 1.55lbs / 0.70kg shells, 1931 Model
Anti-aircraft guns in deck mounts
on side, all amidships
4 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1931 Model
Machine guns in deck mounts
on side, evenly spread
Weight of broadside 654 lbs / 297 kg
Shells per gun, main battery: 150
4 - 18.0" / 457.2 mm submerged torpedo tubes

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

- Conning tower: 1.00" / 25 mm

Machinery:
Diesel Internal combustion motors,
Geared drive, 2 shafts, 17,688 shp / 13,195 Kw = 20.00 kts
Range 8,000nm at 20.00 kts
Bunker at max displacement = 4,411 tons

Complement:
627 - 816

Cost:
£2.268 million / $9.074 million

Distribution of weights at normal displacement:
Armament: 82 tons, 0.6 %
Armour: 33 tons, 0.2 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 21 tons, 0.2 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 12 tons, 0.1 %
Machinery: 529 tons, 3.9 %
Hull, fittings & equipment: 3,855 tons, 28.4 %
Fuel, ammunition & stores: 2,776 tons, 20.5 %
Miscellaneous weights: 6,275 tons, 46.3 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
21,164 lbs / 9,600 Kg = 196.0 x 6.0 " / 152 mm shells or 2.8 torpedoes
Stability (Unstable if below 1.00): 1.10
Metacentric height 3.7 ft / 1.1 m
Roll period: 15.8 seconds
Steadiness - As gun platform (Average = 50 %): 58 %
- Recoil effect (Restricted arc if above 1.00): 0.04
Seaboat quality (Average = 1.00): 1.77

Hull form characteristics:
Hull has raised forecastle
Block coefficient: 0.554
Length to Beam Ratio: 8.06 : 1
'Natural speed' for length: 24.08 kts
Power going to wave formation at top speed: 36 %
Trim (Max stability = 0, Max steadiness = 100): 33
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: 27.00 ft / 8.23 m
- Forecastle (20 %): 25.00 ft / 7.62 m (18.00 ft / 5.49 m aft of break)
- Mid (50 %): 18.00 ft / 5.49 m
- Quarterdeck (15 %): 18.00 ft / 5.49 m
- Stern: 18.00 ft / 5.49 m
- Average freeboard: 19.56 ft / 5.96 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 70.8 %
- Above water (accommodation/working, high = better): 160.0 %
Waterplane Area: 29,253 Square feet or 2,718 Square metres
Displacement factor (Displacement / loading): 169 %
Structure weight / hull surface area: 91 lbs/sq ft or 442 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.99
- Longitudinal: 1.15
- Overall: 1.01
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
Excellent seaboat, comfortable, can fire her guns in the heaviest weather