A bark, also spelled barque, is a sailing vessel with square sails on every mast except the aftermost, which carries fore-and-aft sails. In this three-masted example, the fore and main masts are square rigged and the mizzen is fore-and-aft rigged. The drawing and calculator below explain that arrangement and compare the entered sail areas.
Bark Rig & Sail Area Calculator
Adjust the canvas area of each sail group. The drawing distinguishes square sails from fore-and-aft sails; results show the area totals and their proportions.
Equation Used
- Areas are entered by sail group in square metres.
- Canvas totals do not predict thrust, speed, stability or crew requirements.
- The illustration shows rig type, not a surveyed sail plan.
Here, bark means a sailing vessel distinguished by its arrangement of square and fore-and-aft sails.
How a Bark Rig Works
Yards across the fore and main masts carry square sails. The mizzen uses fore-and-aft sails, including a gaff sail. Headsails attach to stays forward of the foremast. Sheets, braces and halyards control canvas and spars; the simplified diagram shows their arrangement rather than every working line.
Where the Rig Is Used
Barks were used as ocean-going sailing vessels. The arrangement remains visible on preserved ships and sail-training vessels. Rig classification describes how the sails are arranged; it does not specify the size, material or performance of a particular vessel.
Sail Area Calculation
Add the areas of all four groups for total sail area. For this three-masted bark, fore and main square-sail areas form the square-sail total. Mizzen and headsail areas form the remaining fore-and-aft area.
Square-sail share = 100 × (fore + main square area) / total area.
Worked Example
With 280 m² on the foremast, 300 m² on the mainmast, 130 m² on the mizzen and 115 m² in headsails, total area is 825 m². Square canvas is 580 m², or about 70.3% of the total. This percentage describes the example; it is not a required value for a bark.
Bark and Barkentine Compared
A three-masted bark carries square sails on fore and main. A barkentine carries square sails on the foremast only, with fore-and-aft main and mizzen sails. Their sail handling and performance depend on the actual vessel and sail plan; the calculator compares area, not sailing efficiency.
Frequently Asked Questions
Are bark and barque different rigs?
They are alternate spellings of the same rig name.
How does a bark differ from a barkentine?
In a three-masted bark the fore and main are square rigged. In a barkentine only the foremast is square rigged.
Does the calculator predict vessel speed?
No. It totals entered sail areas and identifies their shares. Vessel speed and stability require additional hull, wind, loading and sail information.
Reference
Gardner D. Hiscox, Mechanical Movements, Powers, Devices and Appliances (1901), item 784, printed page 209: A Bark. The adjacent item 782 identifies the barkentine.
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