Ranking Sail o’War
Posted: Wed Sep 16, 2026 8:06 pm
You may remember that Stuart started this off on the old new board. I have attempted to recreate it.
The scoring factors are:
Combat power
* Long-gun broadside weight, converted into British pounds.
* Short-gun broadside weight from carronades, obusiers and similar weapons.
* Structural density: estimated structural mass relative to hull volume.
* Sustainable manpower: crew size adjusted for the ship’s independent endurance.
* Enclosed battery decks: a multiplier reflecting the protection, concentration and redundancy provided by additional gun decks, capped at three decks.
Operational capability
* Sailing power: maximum sail area relative to displacement.
* Maximum speed.
* Hull agility: a geometrical measure derived from length, beam and block coefficient.
* Stability: based on metacentric height.
* Independent endurance.
* Visual horizon: derived from masthead height.
* Fighting freeboard: the height of the lowest gun ports above the water.
The calculation is:
Total score= {combat score} x {deck multiplier} + {operational factors}
Some operational factors are measured above minimum baselines, preventing every ship from receiving a large score merely for possessing the basic characteristics necessary to function as a warship.
The result is not intended to predict the winner of an individual battle. It establishes the measurable capability available on paper. Actual performance can then be compared with that score to examine the effects of construction quality, maintenance, weather, loading, seamanship, gunnery, command and tactical employment.
The model calculates each factor as follows. All foreign measurements are first converted into common British units.
COMBAT POWER
1. Long-gun firepower
Long-gun points equal the weight of one complete long-gun broadside in British pounds, divided by 25.
Example: a 1,000-pound long-gun broadside scores 40 points.
2. Short-gun firepower
Short-gun points equal the weight of one complete broadside from carronades, obusiers and similar short guns, divided by 25.
Example: a 200-pound carronade broadside scores 8 points.
Long and short guns are separated because a carronade provided considerable close-range striking power but could not match the range or general utility of an equivalent long gun.
3. Structural density
First calculate the hull-box volume:
Length in feet multiplied by beam in feet multiplied by structural depth in feet.
Convert the estimated structural weight from tons into pounds by multiplying it by 2,240.
Structural-density points then equal twice the structural weight in pounds, divided by the hull-box volume in cubic feet.
This measures the quantity of structural material contained within a standardised hull volume. It is a proxy for nominal structural strength, not direct proof of construction quality.
4. Sustainable crew capacity
Crew points equal the battle complement divided by 25, multiplied by the ship’s independent endurance in days divided by 120.
Example:
A crew of 750 divided by 25 gives 30.
If the ship has 120 days’ endurance, the endurance adjustment is 120 divided by 120, or 1.
The resulting crew score is 30 points.
This gives manpower value while recognising that a large crew must also be provisioned.
5. Combat core
The combat core equals:
Long-gun points, plus short-gun points, plus structural-density points, plus sustainable-crew points.
6. Enclosed-battery-deck multiplier
One enclosed battery deck gives a multiplier of 1.00.
Two enclosed battery decks give a multiplier of 1.25.
Three or more enclosed battery decks give a multiplier of 1.50.
The multiplier is capped at three decks. It represents the protection, redundancy and concentration of fighting power provided by multiple enclosed gun decks.
7. Adjusted combat score
The adjusted combat score equals the combat core multiplied by the enclosed-battery-deck multiplier.
OPERATIONAL CAPABILITY
8. Sailing power
First calculate the sail index:
Maximum sail area in square feet divided by loaded displacement in tons raised to the power of two-thirds, then divided by 4.
Sailing-power points equal 1.5 times the amount by which the sail index exceeds 50.
If the sail index is 50 or lower, the ship receives zero sailing-power points.
9. Maximum speed
Speed points equal five times the amount by which maximum speed exceeds 8 knots.
Example:
A ship capable of 11 knots exceeds the baseline by 3 knots.
Three multiplied by five gives 15 speed points.
A ship rated at 8 knots or less receives zero speed points.
10. Hull agility
First calculate the agility index:
Ten times beam divided by length, with the result divided by the block coefficient.
Agility points equal ten times the amount by which the agility index exceeds 4.
A ship with an agility index of 4 or less receives zero agility points.
This is a geometrical proxy for turning ability and responsiveness. It does not attempt to include subjective reports of handling or weatherliness.
11. Stability
Stability points equal ten times the amount by which metacentric height exceeds 1 metre.
Example:
A metacentric height of 1.6 metres scores 6 points.
A metacentric height of 1 metre or less scores zero.
12. Independent endurance
Endurance points equal the estimated number of days the ship could remain independently supplied, divided by 10.
Example:
A ship with 120 days of stores scores 12 points.
13. Visual horizon
First calculate the nominal visual horizon:
The square root of masthead height in feet, multiplied by 1.06.
Visual-horizon points equal twice the amount by which this result exceeds 12.
This uses masthead height as a consistent proxy for scouting and detection range.
14. Fighting freeboard
Fighting-freeboard points equal the height of the lowest enclosed gun ports above the waterline in feet, multiplied by two.
Example:
Gun ports 5 feet above the water score 10 points.
This measures the likelihood that the principal battery could be used in rough weather.
15. Operational score
The operational score equals:
Sailing-power points, plus speed points, plus agility points, plus stability points, plus endurance points, plus visual-horizon points, plus fighting-freeboard points.
16. Full ship score
The full score equals:
Adjusted combat score plus operational score.
The score represents the ship’s measurable nominal capability in a specified configuration. It does not include crew training, morale, command quality, maintenance condition, construction defects, tactical position or weather. Those factors are used afterwards to explain why a ship did or did not realise its calculated potential
The scoring factors are:
Combat power
* Long-gun broadside weight, converted into British pounds.
* Short-gun broadside weight from carronades, obusiers and similar weapons.
* Structural density: estimated structural mass relative to hull volume.
* Sustainable manpower: crew size adjusted for the ship’s independent endurance.
* Enclosed battery decks: a multiplier reflecting the protection, concentration and redundancy provided by additional gun decks, capped at three decks.
Operational capability
* Sailing power: maximum sail area relative to displacement.
* Maximum speed.
* Hull agility: a geometrical measure derived from length, beam and block coefficient.
* Stability: based on metacentric height.
* Independent endurance.
* Visual horizon: derived from masthead height.
* Fighting freeboard: the height of the lowest gun ports above the water.
The calculation is:
Total score= {combat score} x {deck multiplier} + {operational factors}
Some operational factors are measured above minimum baselines, preventing every ship from receiving a large score merely for possessing the basic characteristics necessary to function as a warship.
The result is not intended to predict the winner of an individual battle. It establishes the measurable capability available on paper. Actual performance can then be compared with that score to examine the effects of construction quality, maintenance, weather, loading, seamanship, gunnery, command and tactical employment.
The model calculates each factor as follows. All foreign measurements are first converted into common British units.
COMBAT POWER
1. Long-gun firepower
Long-gun points equal the weight of one complete long-gun broadside in British pounds, divided by 25.
Example: a 1,000-pound long-gun broadside scores 40 points.
2. Short-gun firepower
Short-gun points equal the weight of one complete broadside from carronades, obusiers and similar short guns, divided by 25.
Example: a 200-pound carronade broadside scores 8 points.
Long and short guns are separated because a carronade provided considerable close-range striking power but could not match the range or general utility of an equivalent long gun.
3. Structural density
First calculate the hull-box volume:
Length in feet multiplied by beam in feet multiplied by structural depth in feet.
Convert the estimated structural weight from tons into pounds by multiplying it by 2,240.
Structural-density points then equal twice the structural weight in pounds, divided by the hull-box volume in cubic feet.
This measures the quantity of structural material contained within a standardised hull volume. It is a proxy for nominal structural strength, not direct proof of construction quality.
4. Sustainable crew capacity
Crew points equal the battle complement divided by 25, multiplied by the ship’s independent endurance in days divided by 120.
Example:
A crew of 750 divided by 25 gives 30.
If the ship has 120 days’ endurance, the endurance adjustment is 120 divided by 120, or 1.
The resulting crew score is 30 points.
This gives manpower value while recognising that a large crew must also be provisioned.
5. Combat core
The combat core equals:
Long-gun points, plus short-gun points, plus structural-density points, plus sustainable-crew points.
6. Enclosed-battery-deck multiplier
One enclosed battery deck gives a multiplier of 1.00.
Two enclosed battery decks give a multiplier of 1.25.
Three or more enclosed battery decks give a multiplier of 1.50.
The multiplier is capped at three decks. It represents the protection, redundancy and concentration of fighting power provided by multiple enclosed gun decks.
7. Adjusted combat score
The adjusted combat score equals the combat core multiplied by the enclosed-battery-deck multiplier.
OPERATIONAL CAPABILITY
8. Sailing power
First calculate the sail index:
Maximum sail area in square feet divided by loaded displacement in tons raised to the power of two-thirds, then divided by 4.
Sailing-power points equal 1.5 times the amount by which the sail index exceeds 50.
If the sail index is 50 or lower, the ship receives zero sailing-power points.
9. Maximum speed
Speed points equal five times the amount by which maximum speed exceeds 8 knots.
Example:
A ship capable of 11 knots exceeds the baseline by 3 knots.
Three multiplied by five gives 15 speed points.
A ship rated at 8 knots or less receives zero speed points.
10. Hull agility
First calculate the agility index:
Ten times beam divided by length, with the result divided by the block coefficient.
Agility points equal ten times the amount by which the agility index exceeds 4.
A ship with an agility index of 4 or less receives zero agility points.
This is a geometrical proxy for turning ability and responsiveness. It does not attempt to include subjective reports of handling or weatherliness.
11. Stability
Stability points equal ten times the amount by which metacentric height exceeds 1 metre.
Example:
A metacentric height of 1.6 metres scores 6 points.
A metacentric height of 1 metre or less scores zero.
12. Independent endurance
Endurance points equal the estimated number of days the ship could remain independently supplied, divided by 10.
Example:
A ship with 120 days of stores scores 12 points.
13. Visual horizon
First calculate the nominal visual horizon:
The square root of masthead height in feet, multiplied by 1.06.
Visual-horizon points equal twice the amount by which this result exceeds 12.
This uses masthead height as a consistent proxy for scouting and detection range.
14. Fighting freeboard
Fighting-freeboard points equal the height of the lowest enclosed gun ports above the waterline in feet, multiplied by two.
Example:
Gun ports 5 feet above the water score 10 points.
This measures the likelihood that the principal battery could be used in rough weather.
15. Operational score
The operational score equals:
Sailing-power points, plus speed points, plus agility points, plus stability points, plus endurance points, plus visual-horizon points, plus fighting-freeboard points.
16. Full ship score
The full score equals:
Adjusted combat score plus operational score.
The score represents the ship’s measurable nominal capability in a specified configuration. It does not include crew training, morale, command quality, maintenance condition, construction defects, tactical position or weather. Those factors are used afterwards to explain why a ship did or did not realise its calculated potential