Sailing rules suggestions

[KWorld]

[A revised set of sail rules.  Please comment before I add them to the official rules.  :)]

Sailing  Rules

Sailing rigs
A sailing rig to propel a ship, in normal conditions, at a cruising speed of 1/2 the hull's natural speed,  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.  Each additional knot of possible speed, above the hull's natural speed, will weigh 2% 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.  Also, note that the normal sailing cruise speed is governed not only by the ships capability to catch the wind, but by the wind available: if the wind is blowing at 10 knots, a ship with the ability to cruise under sail at 20 knots will not make 20 knots, because there's not enough wind to drive the ship at that speed.

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.


Example:
A ship has (in SS3) a natural speed of 18 knots.  If 5% of the ships normal displacement is reserved as above-decks miscellaneous weight and designated as sails and rigging, this ship would have a normal cruise speed, under sail, of up to 9 knots (because that is half of 18 knots).  Up to an additional 9% of the ships normal displacement could be reserved as above-decks miscellaneous weight and designated as sails and rigging, which would bring the normal cruise speed, under sail, up to 18 knots.  If the designer wanted to allow for even more speed under sail, an additional 2% of ships normal displacement could be installed to bring the normal sailing cruise speed up by 1 knot.

[Jefgte]

Please KW, Post an numeric example.
--
Please, complet, modify or delete the Topics
"Rules of the game"

IMO & every where for all rules, Numerics examples are better than much bla bla bla

Thanks

Jef  ;)

[KWorld]

Well, here's an example:

USS Wampanoag, USA steam frigate laid down 1870
Corvette (Unarmoured)

Displacement:
   3,123 t light; 3,277 t standard; 3,450 t normal; 3,589 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 / 15.49 ft)
   (102.11 m / 102.11 m) x 13.56 m  x (4.57 / 4.72 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 - 9.00" / 229 mm 10.0 cal guns - 80.00lbs / 36.29kg 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 1,401 lbs / 636 kg

Machinery:
   Coal fired boilers, simple reciprocating steam engines,
   Direct drive, 1 shaft, 5,664 ihp / 4,226 Kw = 17.00 kts
   Range 2,000nm at 7.00 kts
   Bunker at max displacement = 312 tons (100% coal)

Complement:
   224 - 292

Cost:
   £0.342 million / $1.368 million

Distribution of weights at normal displacement:
   Armament: 109 tons, 3.2 %
      - Guns: 109 tons, 3.2 %
   Machinery: 1,378 tons, 39.9 %
   Hull, fittings & equipment: 1,256 tons, 36.4 %
   Fuel, ammunition & stores: 327 tons, 9.5 %
   Miscellaneous weights: 380 tons, 11.0 %
      - Above deck: 380 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     1,174 lbs / 533 Kg = 3.4 x 10.0 " / 254 mm shells or 0.5 torpedoes
   Stability (Unstable if below 1.00): 1.34
   Metacentric height 2.5 ft / 0.8 m
   Roll period: 11.8 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.24
   Seaboat quality  (Average = 1.00): 1.26

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.540 / 0.544
   Length to Beam Ratio: 7.53 : 1
   'Natural speed' for length: 18.30 kts
   Power going to wave formation at top speed: 42 %
   Trim (Max stability = 0, Max steadiness = 100): 56
   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 %,  11.00 ft / 3.35 m,  9.00 ft / 2.74 m
      - Forward deck:   30.00 %,  9.00 ft / 2.74 m,  8.00 ft / 2.44 m
      - Aft deck:   35.00 %,  8.00 ft / 2.44 m,  8.00 ft / 2.44 m
      - Quarter deck:   15.00 %,  8.00 ft / 2.44 m,  8.00 ft / 2.44 m
      - Average freeboard:      8.51 ft / 2.59 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 141.5 %
      - Above water (accommodation/working, high = better): 69.8 %
   Waterplane Area: 9,978 Square feet or 927 Square metres
   Displacement factor (Displacement / loading): 98 %
   Structure weight / hull surface area: 91 lbs/sq ft or 447 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.99
      - Longitudinal: 1.12
      - Overall: 1.00
   Cramped machinery, storage, compartmentation space
   Cramped accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

Warning: Shell weight too light2nd Battery

10" guns are rifled pivot guns mounted fore and aft, while the 9" 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 15 knots in normal conditions (11% of normal displacement).


---------
11% of normal displacement is sufficient to propel USS Wampanoag at up to 15 knots because her hull's natural speed is 18.30 knots, giving her a speed of 9 knots under normal sail (5% of normal displacement).  The additional 6% of normal displacement installed gives her a normal speed of up to 15 knots.

[Darman]

I like this. 

[Logi]

I have to disagree. I DON'T like this, mainly for the reason that the misc. weight is based on NORMAL displacement rather than LIGHT displacement.

My reasoning is as follows:
We are building ships to the light displacement standard, to make the book-keeping easy we tend to design our warships to a a nice 250, 500, 1000 ton increment.
These numbers do not translate to the normal displacement, which will come out with an ugly number as a result.
Hence, a rule based on normal displacement will invariably produce nasty misc weight numbers with multiple decimal places.

Case in point, I have a design of 2,500 tons Light weight which is 2,769 tons normal. The 5% rule on normal displacement results in a 138.45 rigging weight. Two decimal places.

I also have to point out, if I remove/add anything to the ship that doesn't change light displacement like range, number of guns, number of shells, etc. I have tor recalculate the sail&rigging weight. Honestly, that's a hassle.

[KWorld]

Sailing rig displacement CANNOT be based on light displacement because light displacement is when the ship is unloaded, and higher in the water.  Using normal displacement gives a reasonable average speed for a trip where the ship uses it's engine and its other consumables.  The only other option is max displacement.

[Walter]

All the sims that you make are based on the normal displacement. The speed you enter in the sim is your speed at normal displacement.

If you need 138.45 tons, you either make it 138 or 139.

[KWorld]

If you need 138.45 tons, you either make it 138 or 139.

Exactly: just round to the nearest whole ton.

[Darman]

If you need 138.45 tons, you either make it 138 or 139.

Exactly: just round to the nearest whole ton.

Its what I've been doing.  Generally rounding up just in case. 

[Logi]

We build ships in light displacement. I calculate my strength based on light displacement. I've used SS enough that I know how much displacement every change will cost to light displacement. Sails are not easy to calculate because of the way the numbers go. I have to take out a calculator. This is very irritating.

If we are going to be so dependent on normal displacement, why don't we just build to / spend BPs in normal displacement.  I would rather not have the extra hassle of having to recalculate every time something changes on the ship.

I design by going through the design cycles 10-20 times per scheme and typically have 4-5 schemes per hull. Recalculating for sail weight gets old real fast.

[Walter]

If you change the length, you'll have to recalculate anyway.

... maybe I should add the calculations to one of my spreadsheets...

[KWorld]

We PAY for ships in light displacement.  There's no reason to pay for them in normal displacement, because that means we're paying for fuel and water and etc (which we pay for with maintenance).

[Darman]

Sure calculating the sails in means I have to alter my design slightly, but when my designs have sails I generally put in a nice buffer of misc weight and calculate down at the end.  We should not alter the weight we pay for sails and rigging to be based on light displacement as opposed to the current normal displacement. 

[Logi]

I would rather pay extra for the ships by paying for normal displacement than light displacement. I don't see why the argument against going to normal displacement is realism. It's not like the sail speed system is realistic. A 196' ft boat that is 6000 tons goes at the same sail speed as a boat of 500 tons.

If we wanted to be realistic at all, the sail speed would be a function of the displacement, Froude-number with relation to the hollow and swells, and weight.
The current system has only 1 ingredient, and is not backed by any hard data. Please don't use realism as your battle call.

If you change the length, you'll have to recalculate anyway.

Sure calculating the sails in means I have to alter my design slightly, but when my designs have sails I generally put in a nice buffer of misc weight and calculate down at the end.  We should not alter the weight we pay for sails and rigging to be based on light displacement as opposed to the current normal displacement. 

Since the period ships are weight-critical, not volume-critical, space is mostly eliminated from the design spiral. There are no fixed weights and the variable weight is dependent on the displacement/hull dimensions. This pushes displacement and hull dimensions to the second things considered, variable weight has to follow as third. A lot of the other steps on the design spiral are eliminated by the limitations of Springsharp and it ends up with Variable Weights as one of the last things considered. As a corollary, hull dimensions don't change within schemes.

Invariable variabe weights will be the last thing considered in this case. The fact that you make a buffer weight first for sails on your ship is just a reflection of your low emphasis on the core naval staff requirements and the higher emphasis on other attributes.