Sailing Rules
[A couple quick ideas, since people seem interested in an 1870 or so start period. Please comment, these are just thoughts I've had in the last couple hours as I got ready to go to work.]
Sailing rigs
A sailing rig to propel a ship, in normal conditions, at a cruising speed of 7 knots, will weigh 5% of the ships NORMAL displacement. Each additional knot of possible speed, up to the hull's natural speed, will weigh 1% of the ships normal displacement. In the proper conditions, a normal ship-rigged vessel can exceed it's cruising speed by up to 5 knots, by setting extra sails and sailing across the wind.
Sailing
Generally, a sailing voyage has to consider the wind. If travelling east or west around the globe, the savvy captain will make use of the trade winds to push him on his way. If travelling north or south, the captain will be cutting across the trade winds in the higher latitudes, but must be aware of the lack of trade winds in the equatorial regions and adjust his route accordingly to make use of more coastal winds (with the related risks of shoal waters and hostile shores). Sailing ships generally cannot move upwind, they can only move across the wind or downwind.
Steam and sail operation
It is quite possible to operate under both steam and sail power at the same time, should the wind be running in the proper direction and the captain desiring more speed.
USS Iowa, USA armored steam frigate laid down 1870)
Displacement:
3,260 t light; 3,423 t standard; 3,642 t normal; 3,817 t full load
Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(335.00 ft / 335.00 ft) x 44.50 ft x (15.00 / 15.59 ft)
(102.11 m / 102.11 m) x 13.56 m x (4.57 / 4.75 m)
Armament:
2 - 10.00" / 254 mm 15.0 cal guns - 300.01lbs / 136.08kg shells, 120 per gun
Muzzle loading guns in deck mounts, 1870 Model
2 x Single mounts on centreline ends, evenly spread
10 - 7.50" / 191 mm 10.0 cal guns - 90.00lbs / 40.82kg shells, 100 per gun
Muzzle loading guns in broadside mounts, 1870 Model
10 x Single mounts on sides, evenly spread
24 - 0.45" / 11.4 mm 45.0 cal guns - 0.04lbs / 0.02kg shells, 400 per gun
Breech loading guns in deck mounts, 1870 Model
4 x Single mounts on side ends, evenly spread
4 raised mounts
Weight of broadside 1,501 lbs / 681 kg
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 4.50" / 114 mm 217.75 ft / 66.37 m 8.00 ft / 2.44 m
Ends: Unarmoured
Main Belt covers 100 % of normal length
- Protected deck - single deck:
For and Aft decks: 1.00" / 25 mm
Machinery:
Coal fired boilers, simple reciprocating steam engines,
Direct drive, 1 shaft, 3,722 ihp / 2,777 Kw = 15.00 kts
Range 2,500nm at 7.00 kts
Bunker at max displacement = 394 tons (100% coal)
Complement:
233 - 304
Cost:
£0.270 million / $1.079 million
Distribution of weights at normal displacement:
Armament: 78 tons, 2.2 %
- Guns: 78 tons, 2.2 %
Armour: 490 tons, 13.4 %
- Belts: 333 tons, 9.1 %
- Armour Deck: 157 tons, 4.3 %
Machinery: 912 tons, 25.1 %
Hull, fittings & equipment: 1,379 tons, 37.9 %
Fuel, ammunition & stores: 382 tons, 10.5 %
Miscellaneous weights: 400 tons, 11.0 %
- Above deck: 400 tons
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
2,880 lbs / 1,306 Kg = 8.2 x 10.0 " / 254 mm shells or 1.0 torpedoes
Stability (Unstable if below 1.00): 1.26
Metacentric height 2.3 ft / 0.7 m
Roll period: 12.4 seconds
Steadiness - As gun platform (Average = 50 %): 75 %
- Recoil effect (Restricted arc if above 1.00): 0.34
Seaboat quality (Average = 1.00): 1.51
Hull form characteristics:
Hull has a flush deck,
a normal bow and a cruiser stern
Block coefficient (normal/deep): 0.570 / 0.575
Length to Beam Ratio: 7.53 : 1
'Natural speed' for length: 18.30 kts
Power going to wave formation at top speed: 36 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 0.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 20.00 %, 13.00 ft / 3.96 m, 11.00 ft / 3.35 m
- Forward deck: 30.00 %, 11.00 ft / 3.35 m, 10.00 ft / 3.05 m
- Aft deck: 35.00 %, 10.00 ft / 3.05 m, 10.00 ft / 3.05 m
- Quarter deck: 15.00 %, 10.00 ft / 3.05 m, 10.00 ft / 3.05 m
- Average freeboard: 10.51 ft / 3.20 m
Ship tends to be wet forward
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 90.9 %
- Above water (accommodation/working, high = better): 86.3 %
Waterplane Area: 10,317 Square feet or 958 Square metres
Displacement factor (Displacement / loading): 122 %
Structure weight / hull surface area: 93 lbs/sq ft or 453 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.97
- Longitudinal: 1.35
- Overall: 1.00
Adequate machinery, storage, compartmentation space
Cramped accommodation and workspace room
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable, can fire her guns in the heaviest weather
10" guns are rifled pivot guns mounted fore and aft, while the 7.5" guns are smoothbore weapons on the broadside. .45" guns are 6-barrelled Gatlings on pivot mounts atop the deckhouse amidships.
Above-decks miscellaneous weight is masts and sails sufficient to propel the ship at up to 13 knots in normal conditions (11% of normal displacement). Under combined sail and steam power, 17 knots is achievable under normal conditions.
For comparison I tried to look up the weight distribution of some sailing ships, without much luck though.
I did found out, that the current "Gorch Fock" training ship carries about 300 tons of ballast in her kneel. Mind you, she is only a 1640 ts (max) ship about 80 meters long with a top speed of around 16 knots (under sail).
I just had a (completely) different idea for the sails:
- choose top speed as ususal
- add misc wight for every horsepower the ships supposed to have under sail
Quote from: Nobody on July 12, 2013, 06:46:13 AM
For comparison I tried to look up the weight distribution of some sailing ships, without much luck though.
I did found out, that the current "Gorch Fock" training ship carries about 300 tons of ballast in her kneel. Mind you, she is only a 1640 ts (max) ship about 80 meters long with a top speed of around 16 knots (under sail).
I just had a (completely) different idea for the sails:
- choose top speed as ususal
- add misc wight for every horsepower the ships supposed to have under sail
Heh, I haven't seen much of anything that covers how much weight there was in masts, sails, and all the stays and guy lines needed to hold them in place either.
The percentage system I created is essentially doing the same thing as adding misc weight for every horsepower under sail from the reverse side. To use the example ship, to cruise at under sail 13 knots she needs 2241 hp. If I used 5 hp per ton as how much sail horsepower per ton were available, that means the ship would need 448 tons to sail at up to 13 knots under sail at cruise.
So... for simming purposes can we assume that this is the basis for a new rule on sails? Just because I want to start simming a few warships.
I have been using this rule for my sims already. No one objected to it so we should use it then. :)
I haven't looked into any historical detail, but I've been using it as well. I would suppose there are no objections at the moment from anyone.
From the looking I did before I created these, the speed seems right. What could very well be off is the weight, but I haven't been able to find much that gives the weight of period masts, sails, rigging, and crew to operate those. :( So I came up with an estimate.
I'm have no idea if the weights and speeds are adequate.
There is one thing I would criticizes though:
There is no advantage for a longer ship in there (except a higher possible top speed at ridiculous cost maybe).
So maybe use a ships half (or third) natural speed instead of the fixed 7 knots for 5% displacement? And leave the rest (+1 kn per % spent extra).
Quote from: Nobody on August 12, 2013, 09:24:27 AM
So maybe use a ships half (or third) natural speed instead of the fixed 7 knots for 5% displacement? And leave the rest (+1 kn per % spent extra).
I kind of like this idea, because then it gives people who design their ships for a faster natural speed a bonus, rather than having to spend more weight to make up the difference in speed. I could have a ship with a natural speed of 7 knots and only pay 5% of my normal weight versus someone who did a much better job and has a natural speed of 10 knots, they have to pay 8% to get the full benefits of their vessel's natural speed.
I believe that it would be great if we could get the perfect historical numbers, but that is highly unlikely and so what we need instead is a serviceable system that can be applied consistently and is loosely based on historic figures.
Historically, the fastest sailing ship built until a multi-hull took the title in 19844, the clipper ship Sovereign of the Seas hit 22 knots in 1854. She had a length of 525 feet, which in SS would giver her a natural speed of 15.87 knots. I don't think it's a good idea to cut that natural speed in half just because she's a sailing ship.
Quote from: KWorld on August 12, 2013, 05:04:22 PM
Historically, the fastest sailing ship built until a multi-hull took the title in 19844, the clipper ship Sovereign of the Seas hit 22 knots in 1854. She had a length of 525 feet, which in SS would giver her a natural speed of 15.87 knots. I don't think it's a good idea to cut that natural speed in half just because she's a sailing ship.
The way I read Nobody's proposal was not to halve the natural speed of a ship outright, it was to pay 5% of its normal displacement for sails and rigging for half the natural speed, rather than a set 7 knots. So the
Sovereign of the Seas, in order to hit 16 knots (I rounded the natural speed up), would need to have 14% of her displacement as misc weight for sails and rigging under the current rules. Under what I believe is Nobody's suggestion (and which I agree with), the
Sovereign would need to have 13% of her misc weight as sails and rigging. (5% misc weight= half the natural speed, 8 knots + 8% misc weight for the 8 additional knots of speed)
We could also give another little twist on the equation to be able to emulate the Sovereign's feat whereby for every additional knot of maximum speed past her natural speed you must pay 2% of displacement.
Gracious, I totally messed up that post about Sovereign of the Seas, didn't I? She was 252 feet long, and her record wasn't surpassed until 1984. Yeesh.....
Keep in mind that Sovereign of the Seas, like the other clippers, was a merchant ship, intended to carry cargo (admittedly at speeds greater than the norm in their day). A quick attempt at SS'ing her is below, but note the instability.
Sovereign of the Seas, United States Clipper ship laid down 1852
Displacement:
5,167 t light; 5,273 t standard; 5,273 t normal; 5,273 t full load
Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(252.00 ft / 252.00 ft) x 45.60 ft x (29.20 / 29.20 ft)
(76.81 m / 76.81 m) x 13.90 m x (8.90 / 8.90 m)
Machinery:
No fuel, Internal combustion motors,
No drive to shaft, 0 shafts, 28,512 shp / 21,270 Kw = 22.00 kts
Range 0nm at 0.00 kts
Bunker at max displacement = 0 tons
Caution: Too much power for number of propellor shafts
Complement:
309 - 402
Cost:
£0.181 million / $0.723 million
Distribution of weights at normal displacement:
Armament: 0 tons, 0.0 %
Machinery: 0 tons, 0.0 %
Hull, fittings & equipment: 2,097 tons, 39.8 %
Fuel, ammunition & stores: 105 tons, 2.0 %
Miscellaneous weights: 3,070 tons, 58.2 %
- Hull below water: 2,050 tons
- Above deck: 1,020 tons
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
3,306 lbs / 1,500 Kg = 71.2 x 6 " / 152 mm shells or 1.5 torpedoes
Stability (Unstable if below 1.00): 0.92
Metacentric height 1.3 ft / 0.4 m
Roll period: 16.8 seconds
Steadiness - As gun platform (Average = 50 %): 54 %
- Recoil effect (Restricted arc if above 1.00): 0.00
Seaboat quality (Average = 1.00): 1.08
Hull form characteristics:
Hull has a flush deck,
a normal bow and a cruiser stern
Block coefficient (normal/deep): 0.550 / 0.550
Length to Beam Ratio: 5.53 : 1
'Natural speed' for length: 15.87 kts
Power going to wave formation at top speed: 69 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 0.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 20.00 %, 22.00 ft / 6.71 m, 19.00 ft / 5.79 m
- Forward deck: 30.00 %, 19.00 ft / 5.79 m, 17.00 ft / 5.18 m
- Aft deck: 35.00 %, 17.00 ft / 5.18 m, 17.00 ft / 5.18 m
- Quarter deck: 15.00 %, 17.00 ft / 5.18 m, 17.00 ft / 5.18 m
- Average freeboard: 17.94 ft / 5.47 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 43.5 %
- Above water (accommodation/working, high = better): 83.7 %
Waterplane Area: 7,778 Square feet or 723 Square metres
Displacement factor (Displacement / loading): 172 %
Structure weight / hull surface area: 126 lbs/sq ft or 615 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.81
- Longitudinal: 7.03
- Overall: 1.00
Caution: Poor stability - excessive risk of capsizing
Excellent machinery, storage, compartmentation space
Cramped accommodation and workspace room
Warning: Too much power for number of propellor shafts
I made a pure sailing ship with SS using our 7 knots =5% rule. I actually simmed it entering 1 at the speed, shaft, range and cruising speed, so I do not need to worry about any warnings it may give.
I entered the higher speed to get decent seakeeping at speed. The warning about propellors I didn't worry about, since the ship doesn't have props.
I get a bunch of "NaN" warnings with your sim due to the lack of engines... and I guess that is also the reason why I enter those "1"s in my sim.
Sovereign of the Seas, United States Clipper ship laid down 1852
Displacement:
NaN (非数値) t light; NaN (非数値) t standard; 5,273 t normal; NaN (非数値) t full load
Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(252.00 ft / 252.00 ft) x 45.60 ft x (29.20 / NaN (非数値) ft)
(76.81 m / 76.81 m) x 13.90 m x (8.90 / NaN (非数値) m)
Machinery:
No fuel, Internal combustion motors,
No drive to shaft, 0 shafts, 28,512 shp / 21,270 Kw = 22.00 kts
Range 0nm at 0.00 kts
Bunker at max displacement = NaN (非数値) tons
Caution: Too much power for number of propellor shafts
Complement:
309 - 402
Cost:
£NaN (非数値) million / $NaN (非数値) million
Distribution of weights at normal displacement:
Armament: 0 tons, 0.0%
Machinery: NaN (非数値) tons, NaN (非数値)
Hull, fittings & equipment: NaN (非数値) tons, NaN (非数値)
Fuel, ammunition & stores: NaN (非数値) tons, NaN (非数値)
Miscellaneous weights: 3,070 tons, 58.2%
- Hull below water: 2,050 tons
- Above deck: 1,020 tons
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
NaN (非数値) lbs / NaN (非数値) Kg = NaN (非数値) x 6 " / 152 mm shells or NaN (非数値) torpedoes
Stability (Unstable if below 1.00): NaN (非数値)
Metacentric height NaN (非数値) ft / NaN (非数値) m
Roll period: NaN (非数値) seconds
Steadiness - As gun platform (Average = 50 %): NaN (非数値) %
- Recoil effect (Restricted arc if above 1.00): 0.00
Seaboat quality (Average = 1.00): NaN (非数値)
Hull form characteristics:
Hull has a flush deck,
a normal bow and a cruiser stern
Block coefficient (normal/deep): 0.550 / NaN (非数値)
Length to Beam Ratio: 5.53 : 1
'Natural speed' for length: 15.87 kts
Power going to wave formation at top speed: 69 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 0.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 20.00%, 22.00 ft / 6.71 m, 19.00 ft / 5.79 m
- Forward deck: 30.00%, 19.00 ft / 5.79 m, 17.00 ft / 5.18 m
- Aft deck: 35.00%, 17.00 ft / 5.18 m, 17.00 ft / 5.18 m
- Quarter deck: 15.00%, 17.00 ft / 5.18 m, 17.00 ft / 5.18 m
- Average freeboard: 17.94 ft / 5.47 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): NaN (非数値)
- Above water (accommodation/working, high = better): 83.7%
Waterplane Area: 7,778 Square feet or 723 Square metres
Displacement factor (Displacement / loading): NaN (非数値)
Structure weight / hull surface area: NaN (非数値) lbs/sq ft or NaN (非数値) Kg/sq metre
Hull strength (Relative):
- Cross-sectional: NaN (非数値)
- Longitudinal: NaN (非数値)
- Overall: NaN (非数値)
Extremely poor machinery, storage, compartmentation space
Cramped accommodation and workspace room
Warning: Too much power for number of propellor shafts
Interesting...... Here's a revised version:
Sovereign of the Seas, United States Clipper ship laid down 1852
Displacement:
5,167 t light; 5,273 t standard; 5,273 t normal; 5,273 t full load
Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(252.00 ft / 252.00 ft) x 45.60 ft x (29.20 / 29.20 ft)
(76.81 m / 76.81 m) x 13.90 m x (8.90 / 8.90 m)
Machinery:
Immobile floating battery
Complement:
309 - 402
Cost:
£0.181 million / $0.723 million
Distribution of weights at normal displacement:
Armament: 0 tons, 0.0 %
Machinery: 0 tons, 0.0 %
Hull, fittings & equipment: 1,999 tons, 37.9 %
Fuel, ammunition & stores: 105 tons, 2.0 %
Miscellaneous weights: 3,168 tons, 60.1 %
- Hull below water: 1,000 tons
- Hull above water: 850 tons
- Above deck: 1,318 tons
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
1,716 lbs / 778 Kg = 37.0 x 6 " / 152 mm shells or 0.7 torpedoes
Stability (Unstable if below 1.00): 0.77
Metacentric height 0.8 ft / 0.2 m
Roll period: 21.2 seconds
Steadiness - As gun platform (Average = 50 %): 100 %
- Recoil effect (Restricted arc if above 1.00): 0.00
Seaboat quality (Average = 1.00): 2.00
Hull form characteristics:
Hull has a flush deck,
a normal bow and a cruiser stern
Block coefficient (normal/deep): 0.550 / 0.550
Length to Beam Ratio: 5.53 : 1
'Natural speed' for length: 15.87 kts
Power going to wave formation at top speed: 0 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 0.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 20.00 %, 22.00 ft / 6.71 m, 19.00 ft / 5.79 m
- Forward deck: 30.00 %, 19.00 ft / 5.79 m, 17.00 ft / 5.18 m
- Aft deck: 35.00 %, 17.00 ft / 5.18 m, 17.00 ft / 5.18 m
- Quarter deck: 15.00 %, 17.00 ft / 5.18 m, 17.00 ft / 5.18 m
- Average freeboard: 17.94 ft / 5.47 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 39.5 %
- Above water (accommodation/working, high = better): 83.7 %
Waterplane Area: 7,778 Square feet or 723 Square metres
Displacement factor (Displacement / loading): 166 %
Structure weight / hull surface area: 120 lbs/sq ft or 587 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.81
- Longitudinal: 6.70
- Overall: 1.00
Caution: Poor stability - excessive risk of capsizing
Excellent machinery, storage, compartmentation space
Cramped accommodation and workspace room
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable, rides out heavy weather easily
Above decks weight is masts and sails sufficient to drive the ship at 22 knots (25% normal displacement).
I get the same "NaN" warning with that version as well. I tried with an older SS3 version I still have and got the same warning. All due to the fact that the engines have not been selected.
Edit: Would the 25% of the normal displacement not give you 27 knots?
Odd. I'm just using SS3b3, so nothing special, and if I load it up from the file it loads fine and gives no NaN errors.
As far as the speed goes, I was using Darman's proposal for extra cost for over natural speed.
So do I. If others do not have that problem, then the only thing I can think of that is causing it is because of my computer settings to run certain things (which should be obvious with the "(非数値)" bits in my report).
With that second sim, you used 1/3 of the natural speed as test?
Stability is a lot worse on that one due to the additional weight higher up in the ship. With the first one, you could correct it with the trim, but the second one is beyond trimming...
Quote from: KWorld on August 13, 2013, 01:00:23 PM
As far as the speed goes, I was using Darman's proposal for extra cost for over natural speed.
Quote from: Walter on August 13, 2013, 01:13:49 PM
With that second sim, you used 1/3 of the natural speed as test?
I was advocating using 1/2 of the natural speed as costing 5% displacement, plus 1% displacement for every additional knot up to the natural speed and 2% for every additional knot of maximum speed.
Quote from: Walter on August 13, 2013, 01:13:49 PM
With that second sim, you used 1/3 of the natural speed as test?
Stability is a lot worse on that one due to the additional weight higher up in the ship. With the first one, you could correct it with the trim, but the second one is beyond trimming...
The additional weight is because I adjusted the draft of the ship to match the original, which drove up her normal displacement.
QuoteThe additional weight is because I adjusted the draft of the ship to match the original, which drove up her normal displacement.
Originally, you had 2050 tons below the waterline. With the second sim, it is only 1000 tons. The shift of those 1050 tons to positions above the waterline (a.k.a "the additional weight higher up in the ship" that I mentioned) is what dragged the stability down from 0.92 to 0.77.