Boooring!

[Guinness]

I actually need some opinions on this though. Especially if I've calculated the costs correctly. A CSA troop transport, built to merchant standards including VTE engines, but with 3 screws. I included the machinery in the cost, even though it's VTE, because of the 3 screws:

CSA Troopship, CSA Troopship laid down 1912 (Engine 1909)

Displacement:
   17,300 t light; 17,740 t standard; 21,558 t normal; 24,613 t full load

Dimensions: Length overall / water x beam x draught
   562.00 ft / 557.00 ft x 92.50 ft x 24.41 ft (normal load)
   171.30 m / 169.77 m x 28.19 m  x 7.44 m

Armament:
      1 - 4.75" / 121 mm guns in single mounts, 50.00lbs / 22.68kg shells, 1912 Model
     Breech loading gun in deck mount
     on centreline forward
      2 - 3.50" / 88.9 mm guns in single mounts, 21.44lbs / 9.72kg shells, 1912 Model
     Quick firing guns in deck mounts
     on side, all amidships
      2 - 1.00" / 25.4 mm guns in single mounts, 0.50lbs / 0.23kg shells, 1912 Model
     Anti-aircraft guns in deck mounts
     on side, evenly spread
   Weight of broadside 94 lbs / 43 kg
   Shells per gun, main battery: 150

Machinery:
   Oil fired boilers, complex reciprocating steam engines,
   Direct drive, 3 shafts, 29,426 ihp / 21,952 Kw = 21.00 kts
   Range 7,000nm at 18.00 kts
   Bunker at max displacement = 6,873 tons

Complement:
   889 - 1,156

Cost:
   £0.904 million / $3.615 million

Distribution of weights at normal displacement:
   Armament: 12 tons, 0.1 %
   Machinery: 2,058 tons, 9.5 %
   Hull, fittings & equipment: 5,130 tons, 23.8 %
   Fuel, ammunition & stores: 4,258 tons, 19.8 %
   Miscellaneous weights: 10,100 tons, 46.8 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     26,307 lbs / 11,932 Kg = 490.9 x 4.8 " / 121 mm shells or 3.0 torpedoes
   Stability (Unstable if below 1.00): 1.20
   Metacentric height 6.2 ft / 1.9 m
   Roll period: 15.6 seconds
   Steadiness   - As gun platform (Average = 50 %): 52 %
         - Recoil effect (Restricted arc if above 1.00): 0.00
   Seaboat quality  (Average = 1.00): 1.68

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.600
   Length to Beam Ratio: 6.02 : 1
   'Natural speed' for length: 23.60 kts
   Power going to wave formation at top speed: 45 %
   Trim (Max stability = 0, Max steadiness = 100): 31
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 5.00 ft / 1.52 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      30.00 ft / 9.14 m
      - Forecastle (20 %):   17.00 ft / 5.18 m
      - Mid (50 %):      17.00 ft / 5.18 m
      - Quarterdeck (15 %):   17.00 ft / 5.18 m
      - Stern:      18.00 ft / 5.49 m
      - Average freeboard:   18.12 ft / 5.52 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 82.9 %
      - Above water (accommodation/working, high = better): 137.3 %
   Waterplane Area: 37,683 Square feet or 3,501 Square metres
   Displacement factor (Displacement / loading): 151 %
   Structure weight / hull surface area: 103 lbs/sq ft or 501 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.98
      - Longitudinal: 1.18
      - Overall: 1.00
   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

Misc Weights:

25t Marconi
475t Boats, launches, and other craft, and related cranes, etc.
600t Other cargo
9000t for Troops = 4500 troops and officers and their equipment

Ship built to merchant standards
Costs:
$9.04 * 0.25 = $2.26, hull etc.
2070 tons of machinery, armament and armor  = 2.07 BP and $2.07

Total costs:
BP: 2.07 BP and $4.33

[The Rock Doctor]

I intend to delete the requirement for single screws in civilian-standard ships.

That being said - your costing model needs a bit of work.  It should be:

(light displacement other than guns/armour)*0.25

plus

(light displacement of guns/armour)

...so probably in the area of 4.3 BP and $4.30

[Guinness]

The current rule says:

The ships costs 1/4th of the total SS price to build. The Springsharp indicated weight of non-VTE machinery, armament and armor is to be paid from BP. Plus $ at rate of 1$ per 1000 tonnes of machinery, armament and armour.

That's where my figures came from. No mention of BP for the hull, etc., just for the military equipment.

[The Rock Doctor]

I had understood the cost to be both BP and $.  Perhaps other folks would care to share what they understood the rule to mean?

[Borys]

Ahoj!

I had understood the cost to be both BP and $.  Perhaps other folks would care to share what they understood the rule to mean?

I no longer remember.

Maybe it can be dug up in the Moderator's Board.

But (1/4th $ +0% BP) for civilian part +(100% $ and 100% BP) for the military part makes sense. After a major row we had decided that we need not keep track of how much BP goes into civilian shipping or railroad steam engines. But my brai ain't what it used to be.

Borys

[P3D]

1/4 of both the BP and $.
Engine $ cost is Double the BP cost.

IMO too large - the clipper bow won't fit into lvl 2 drydock. For 21kts turbines are better. I personally try to keep the length of auxiliaries to 120m/383'.

[Sachmle]

Is it just me, or is 21kts a little fast for an aux. anyway? I'd figure 18kts for top speed and 10-12kts cruising speed. Then no need for turbines.  ;)

[Guinness]

Well, there's some concern that she needs to be able to run through unfriendly seas, in case of submarines, raiders, etc.

I'm working on something entirely different for a similar purpose now, but that'll have to wait until after Independence Day celebrations.

[Sachmle]

Well, there's some concern that she needs to be able to run through unfriendly seas, in case of submarines, raiders, etc.

I'm working on something entirely different for a similar purpose now, but that'll have to wait until after Independence Day celebrations.

Wouldn't she be escorted by at least enough ships to provide shore bombardment?

[Guinness]

Ok, I came back to this topic. A couple more passes at CSA amphibious transports. Note on the costs: I figured these based on 1/4 the SS cost of the ship (merchant standard), plus cost in BP and $ of all the misc weights all lumped together. I feel like the misc weight of what's being carried should be exempt though. This would include the cargo, and say about 1/4 a ton per soldier. I'm happy to pay for the boats, etc. under the 1 BP and $1 per 1000 ton rule, however.

At any rate, here they are, one large and one small. The small ship has the distinct advantage of being buildable in a type 1 slip.

1913 CSA Amphibious Transport Large , CSA Amphibious Transport laid down 1913 (Engine 1912)

Displacement:
   10,000 t light; 10,242 t standard; 10,992 t normal; 11,593 t full load

Dimensions: Length overall / water x beam x draught
   480.00 ft / 465.00 ft x 74.50 ft x 17.09 ft (normal load)
   146.30 m / 141.73 m x 22.71 m  x 5.21 m

Armament:
      2 - 5.50" / 140 mm guns in single mounts, 80.00lbs / 36.29kg shells, 1913 Model
     Breech loading guns in deck mounts
     on centreline ends, evenly spread
      4 - 3.50" / 88.9 mm guns in single mounts, 20.00lbs / 9.07kg shells, 1913 Model
     Breech loading guns in deck mounts
     on side, all amidships
      8 - 1.00" / 25.4 mm guns (4x2 guns), 0.50lbs / 0.23kg shells, 1913 Model
     Breech loading guns in deck mounts
     on side, evenly spread
   Weight of broadside 244 lbs / 111 kg
   Shells per gun, main battery: 150

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   2.00" / 51 mm         -               -
   2nd:   1.50" / 38 mm         -               -
   3rd:   1.00" / 25 mm         -               -

Machinery:
   Oil fired boilers, complex reciprocating steam engines,
   Direct drive, 2 shafts, 8,000 ihp / 5,968 Kw = 16.19 kts
   Range 8,000nm at 10.00 kts
   Bunker at max displacement = 1,351 tons

Complement:
   536 - 697

Cost:
   £0.485 million / $1.939 million

Distribution of weights at normal displacement:
   Armament: 32 tons, 0.3 %
   Armour: 26 tons, 0.2 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 26 tons, 0.2 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 0 tons, 0.0 %
   Machinery: 482 tons, 4.4 %
   Hull, fittings & equipment: 3,375 tons, 30.7 %
   Fuel, ammunition & stores: 993 tons, 9.0 %
   Miscellaneous weights: 6,085 tons, 55.4 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     20,509 lbs / 9,303 Kg = 246.5 x 5.5 " / 140 mm shells or 2.5 torpedoes
   Stability (Unstable if below 1.00): 1.10
   Metacentric height 3.9 ft / 1.2 m
   Roll period: 15.9 seconds
   Steadiness   - As gun platform (Average = 50 %): 58 %
         - Recoil effect (Restricted arc if above 1.00): 0.02
   Seaboat quality  (Average = 1.00): 2.00

Hull form characteristics:
   Hull has rise aft of midbreak
   Block coefficient: 0.650
   Length to Beam Ratio: 6.24 : 1
   'Natural speed' for length: 21.56 kts
   Power going to wave formation at top speed: 35 %
   Trim (Max stability = 0, Max steadiness = 100): 29
   Bow angle (Positive = bow angles forward): 10.89 degrees
   Stern overhang: 10.00 ft / 3.05 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      26.00 ft / 7.92 m
      - Forecastle (10 %):   26.00 ft / 7.92 m
      - Mid (50 %):      25.00 ft / 7.62 m (26.00 ft / 7.92 m aft of break)
      - Quarterdeck (25 %):   25.00 ft / 7.62 m
      - Stern:      25.00 ft / 7.62 m
      - Average freeboard:   25.43 ft / 7.75 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 77.2 %
      - Above water (accommodation/working, high = better): 240.5 %
   Waterplane Area: 26,538 Square feet or 2,465 Square metres
   Displacement factor (Displacement / loading): 150 %
   Structure weight / hull surface area: 87 lbs/sq ft or 425 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.91
      - Longitudinal: 2.24
      - Overall: 1.00
   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

Misc Weights:

4400t: 2200 troops
330t: 6 20 ton boats for 80 troops each, 16 10 ton boats with capacity for 40 troops each, + fittings, including derricks and cranes, etc.
1000t: Cargo
120t: Cargo derricks and other gear
25t: wireless
10t: wireless

Costs:
Hull: 1/4 of $4.85 = $1.2125 + 2.5 BP
Armament and Armor: 58 tons = .058 BP and $0.058
Misc Weights: 6085 tons = 6.085 BP and $6.085

Totals: 8.643 BP and $7.36

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

1913 CSA Amphibious Transport Small, CSA Amphibious Transport laid down 1913 (Engine 1912)

Displacement:
   6,000 t light; 6,151 t standard; 6,688 t normal; 7,118 t full load

Dimensions: Length overall / water x beam x draught
   393.00 ft / 386.00 ft x 63.75 ft x 15.60 ft (normal load)
   119.79 m / 117.65 m x 19.43 m  x 4.75 m

Armament:
      2 - 4.75" / 121 mm guns in single mounts, 50.00lbs / 22.68kg shells, 1913 Model
     Breech loading guns in deck mounts
     on centreline ends, evenly spread
      4 - 3.50" / 88.9 mm guns in single mounts, 20.00lbs / 9.07kg shells, 1913 Model
     Breech loading guns in deck mounts
     on side, all amidships
      8 - 1.00" / 25.4 mm guns (4x2 guns), 0.50lbs / 0.23kg shells, 1913 Model
     Breech loading guns in deck mounts
     on side, evenly spread
   Weight of broadside 184 lbs / 83 kg
   Shells per gun, main battery: 150

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   2.00" / 51 mm         -               -
   2nd:   1.50" / 38 mm         -               -
   3rd:   1.00" / 25 mm         -               -

Machinery:
   Oil fired boilers, complex reciprocating steam engines,
   Direct drive, 2 shafts, 6,018 ihp / 4,489 Kw = 16.19 kts
   Range 8,000nm at 10.00 kts
   Bunker at max displacement = 967 tons

Complement:
   369 - 480

Cost:
   £0.307 million / $1.228 million

Distribution of weights at normal displacement:
   Armament: 25 tons, 0.4 %
   Armour: 24 tons, 0.4 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 24 tons, 0.4 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 0 tons, 0.0 %
   Machinery: 362 tons, 5.4 %
   Hull, fittings & equipment: 2,153 tons, 32.2 %
   Fuel, ammunition & stores: 688 tons, 10.3 %
   Miscellaneous weights: 3,435 tons, 51.4 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     13,080 lbs / 5,933 Kg = 244.1 x 4.8 " / 121 mm shells or 2.0 torpedoes
   Stability (Unstable if below 1.00): 1.10
   Metacentric height 3.1 ft / 0.9 m
   Roll period: 15.3 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.03
   Seaboat quality  (Average = 1.00): 2.00

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.610
   Length to Beam Ratio: 6.05 : 1
   'Natural speed' for length: 19.65 kts
   Power going to wave formation at top speed: 40 %
   Trim (Max stability = 0, Max steadiness = 100): 25
   Bow angle (Positive = bow angles forward): 4.76 degrees
   Stern overhang: 5.00 ft / 1.52 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      24.00 ft / 7.32 m
      - Forecastle (10 %):   24.00 ft / 7.32 m
      - Mid (50 %):      24.00 ft / 7.32 m
      - Quarterdeck (25 %):   24.00 ft / 7.32 m
      - Stern:      24.00 ft / 7.32 m
      - Average freeboard:   24.00 ft / 7.32 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 76.8 %
      - Above water (accommodation/working, high = better): 225.0 %
   Waterplane Area: 18,163 Square feet or 1,687 Square metres
   Displacement factor (Displacement / loading): 153 %
   Structure weight / hull surface area: 75 lbs/sq ft or 366 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.87
      - Longitudinal: 3.35
      - Overall: 1.00
   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

Misc Weights:

2640t: 1320 troops
200t: 3 20 ton boats for 80 troops each, 11 10 ton boats with capacity for 40 troops each, + fittings, including derricks and cranes, etc.
500t: Cargo
60t: Cargo derricks and other gear
25t: wireless
10t: wireless

Costs:
Hull: 1/4 of $3.07 = $0.7675 + 1.5 BP
Armament and Armor: 49 tons = .049 BP and $0.049
Misc Weights: 3435 tons = 3.435 BP and $3.435

Totals: 4.984 BP and $4.25

[P3D]

I find it a bit strange that everyone here (including myself) manages to squeeze twice the number of troops into the same displacement as a WWII AKA transport.

[Guinness]

I think there's a reason for that.

The starting point for me was this http://en.wikipedia.org/wiki/USS_Orizaba_(ID-1536) (caution lame wikipedia link, but this page is pretty good).

3100 troops, 16.5 knots, 6200 mile range on about 11,000 tons. So by that measure, the first one isn't that nuts.

WW2 AKAs carried relatively small numbers of troops, as I understand it, for several reasons:

1. they were all converted cargo (mostly C3) hulls, and not designed for the purpose. So they had plenty of carrying capacity, but not enough volume for all the men and their stuff. Most had to ship with ballast for this reason.
2. They were all combat loaded, so all the equipment each infantry man would need, including lots of ammo and equipment was on-board. This stuff took up lots of space.
3. They had to carry their troops relatively long distances, so they had to carry lots of stores for them too.

I also suspect that one reason it's hard to find their usual troop compliment is that it varied widely. ~1000 might be normal, but they might have been capable of carrying a lot more.

I think the biggest issue with how we design troop ships, cargo ships, tenders, etc. is that SS2 isn't the right tool though. It works mostly on weight, as I understand it, but an AKA is going to be just as much volume sensitive as weight sensitive.

[P3D]

So you say numbers are good for a troop transport, but for an amphibious transport craft, combat load/etc. should reduce capacity to about one-half? :P

I think there's a reason for that.

The starting point for me was this http://en.wikipedia.org/wiki/USS_Orizaba_(ID-1536) (caution lame wikipedia link, but this page is pretty good).

3100 troops, 16.5 knots, 6200 mile range on about 11,000 tons. So by that measure, the first one isn't that nuts.

WW2 AKAs carried relatively small numbers of troops, as I understand it, for several reasons:

1. they were all converted cargo (mostly C3) hulls, and not designed for the purpose. So they had plenty of carrying capacity, but not enough volume for all the men and their stuff. Most had to ship with ballast for this reason.
2. They were all combat loaded, so all the equipment each infantry man would need, including lots of ammo and equipment was on-board. This stuff took up lots of space.
3. They had to carry their troops relatively long distances, so they had to carry lots of stores for them too.

I also suspect that one reason it's hard to find their usual troop compliment is that it varied widely. ~1000 might be normal, but they might have been capable of carrying a lot more.

I think the biggest issue with how we design troop ships, cargo ships, tenders, etc. is that SS2 isn't the right tool though. It works mostly on weight, as I understand it, but an AKA is going to be just as much volume sensitive as weight sensitive.

[Guinness]

Sure, if we want to make that the rule. :)

As it is, by the way, I just realized that it would be cheaper to build these ships under full military rules, and not under the merchant ship rules, which is in and of itself that the rules for these sort of ships probably need an overhaul. I'm not saying we should change the rules now, but this is a glaring example of the problem.

[P3D]

No way it would be cheaper using military standard.