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(Redirected from Square-rig)
'Square rig' is a generic type of sail and rigging arrangement in which the primary driving sails are carried on horizontal spars which are perpendicular to the keel of the vessel and to the masts. These spars are called ''yards'', the tips of which, beyond the last stay, are called the ''yardarms''. A ship at least partially so rigged is called a square rigger.
It can also describe individual, four-cornered sails suspended from the horizontal yards, and carried on either a square rigged or a mainly fore-and-aft rigged vessel, such as one with either a bermuda rigged or gaff rigged mainsail.
The term is also used for the uniform of a rating in the Royal Navy from 1857 onwards. It is slang and refers to anyone wearing the non-peaked cap worn by Petty Officers and Officers this 'rig' includes the famous blue collar on the shoulders and bell-bottomed trousers. This name perhaps reflects the fact that it was these men who managed the square rigged sails.
A mast is considered square rigged if its lowest sail or course is square rigged, but normally if this is the case it will have a complete set of square rigged sails. If the course is fore-and-aft, square topsails can still be carried in front of the mast.
Square-rigged masts may also have staysails that are deployed fore-and-aft between masts.
In their heyday, square-rigged vessels ranged in size from small boats to full rigged ships, however, today this rig has fallen from favour and the rig in common use today is one form or another of fore-and-aft gaff rigs and bermuda rigs. The reason for this change are the development of steam power and new materials. For larger ships, it was only possible to drive large tonnages using multiple sails until steam arrived and made sails unnecessary, although hybrids existed for a while.
The strains imposed on cordage and sails in the Age of Sail meant that a large number of sails were necessary to get the surface area necessary to drive larger ships. Fewer larger sails would not have survived the rigours of the larger commercial and military ships and required more men to manage. Therefore, in order to get the large number of sails to effectively collect wind and provide motive power they had to be square to the hull. There were no examples of the more efficient fore-and-aft rigs on larger vessels for this reason. Despite the large overall sail areas, and even when sailing on their best points of sail, it was sometimes the case that large warships could only make 6-8 knots, while some of the faster clippers for whom speed was critical could make much faster speeds, e.g. Cutty Sark which could make 17 knots.
The square rig breaks up the sail area into many smaller sails, each of which can be individually handled by a relatively small team hauling on their controlling lines. Having many smaller sails also allowed warships to manage the impact of weapons upon them. Instead of losing one very large sail to a hole from a cannonball, which would then tear, the damage was constrained to a much smaller sail area and, therefore, had less impact on the motive power of the vessel. With the development of more advanced fittings, equipment and cordage, particularly geared winches, high loads on an individual line (or rope) became less of an issue, and the focus moved to minimising the number of lines and hence the size of the crew needed to handle them.
It is particularly in the area of hybrid vessels carrying some square-rigged sails that changes due to materials are noticeable. The low aspect ratio of square rigged sails (usually 1/2 to 1/3) produce large amounts of drag for the lift (motive power) that they produce, and thus give very poor performance to windward. This means that they cannot sail as close to the wind. The Bermuda rig is the (nearly) undisputed champion of windward performance in soft sails, due to its very low drag and high lift to drag ratio. Square rigs do have their advantages, however; they are more efficient when running, where the high lift to drag is irrelevant and the total drag is the most important issue. Square rigged sails are less prone to broaching when running than Bermuda rigs.
On a square rigged mast the sails had names which indicated their position on the mast. The lowest square sail was the course, the next sail up the mast was called the topsail, the next the topgallant sail. Some vessels shipped a fourth, sail called the royal, above the other three. Sometimes a vessel might put out studding sails which would be fixed outboard of the sail on both sides of it. Beginning in the mid-nineteenth century, the topsails and topgallants were each split into upper and lower sails; this allowed smaller crews to tend the sails and provided captains with a greater set of options in choosing which sails to set. Sails are referred to by their mast and then name, ''e.g.'', "the fore topgallant sail", often shortened to fore t'gallant.
A square rigged sail is not in fact square, but more nearly trapezoidal, being symmetrical but longer in the foot than the head. Like all sails it is three-dimensional, and its curve or belly means that its foot (lower edge) is not a straight line at all. It is fixed to a spar (the yard) along its head, and its clews (bottom corners) are controlled by sheets, often run to blocks on the spar immediately below the sail.
Modern square-rigged ships are still used for training, tourism and ceremonial purposes.
★ A barque has three or more masts, with the aftermost entirely fore-and-aft rigged, while the fore, main and any others are square rigged.
★ A brig has two masts, both square rigged.
★ A full rigged ship has three or more masts, including a foremast, mainmast and mizzen, and all masts are square rigged.
★ A sloop has only one mast.
All the above rigs normally carry a number of jibs and at least one spanker, and generally carry fore-and-aft staysails between the masts.
★ A barquentine has three or more masts, typically with only the fore square rigged while the main, mizzen and any others are fore-and-aft rigged.
★ A brigantine has two masts: A square rigged foremast and a fore-and-aft rigged mainmast.
★ A square-topsail ketch carries one or more square-rigged topsails (commonly two, an upper and a lower topsail) on its mainmast, in addition to its mainsail, mizzen sail and jibs.
★ A square-topsail schooner carries one or more square-rigged topsails on its foremast. This rig is often simply called a ''topsail schooner'' as topsails above the gaff-rigged sails are a standard part of the schooner rig.
★ A square-topsail cutter or sloop carries one or (less commonly) two square topsails on its only mast, in addition to its mainsail and jib or jibs.
★ The Maltese Falcon, a modern square rigged yacht
★ Sail Training Ships, Square rigged training ships
'Square rig' is a generic type of sail and rigging arrangement in which the primary driving sails are carried on horizontal spars which are perpendicular to the keel of the vessel and to the masts. These spars are called ''yards'', the tips of which, beyond the last stay, are called the ''yardarms''. A ship at least partially so rigged is called a square rigger.
It can also describe individual, four-cornered sails suspended from the horizontal yards, and carried on either a square rigged or a mainly fore-and-aft rigged vessel, such as one with either a bermuda rigged or gaff rigged mainsail.
The term is also used for the uniform of a rating in the Royal Navy from 1857 onwards. It is slang and refers to anyone wearing the non-peaked cap worn by Petty Officers and Officers this 'rig' includes the famous blue collar on the shoulders and bell-bottomed trousers. This name perhaps reflects the fact that it was these men who managed the square rigged sails.
A mast is considered square rigged if its lowest sail or course is square rigged, but normally if this is the case it will have a complete set of square rigged sails. If the course is fore-and-aft, square topsails can still be carried in front of the mast.
A square-rigger, with several of its lines unshipped, in London.
| Contents |
| Characteristics of square rig |
| Sail characteristics |
| Types of square rig |
| Principally square rigged types |
| Fore-and-aft rigs with some square rigged sails |
| External links |
Characteristics of square rig
In their heyday, square-rigged vessels ranged in size from small boats to full rigged ships, however, today this rig has fallen from favour and the rig in common use today is one form or another of fore-and-aft gaff rigs and bermuda rigs. The reason for this change are the development of steam power and new materials. For larger ships, it was only possible to drive large tonnages using multiple sails until steam arrived and made sails unnecessary, although hybrids existed for a while.
USS Atlanta in 1884 showing the hybrid configuration of square rig and steam. A square rigger can be seen in the background.
The square rig breaks up the sail area into many smaller sails, each of which can be individually handled by a relatively small team hauling on their controlling lines. Having many smaller sails also allowed warships to manage the impact of weapons upon them. Instead of losing one very large sail to a hole from a cannonball, which would then tear, the damage was constrained to a much smaller sail area and, therefore, had less impact on the motive power of the vessel. With the development of more advanced fittings, equipment and cordage, particularly geared winches, high loads on an individual line (or rope) became less of an issue, and the focus moved to minimising the number of lines and hence the size of the crew needed to handle them.
Tending sail
It is particularly in the area of hybrid vessels carrying some square-rigged sails that changes due to materials are noticeable. The low aspect ratio of square rigged sails (usually 1/2 to 1/3) produce large amounts of drag for the lift (motive power) that they produce, and thus give very poor performance to windward. This means that they cannot sail as close to the wind. The Bermuda rig is the (nearly) undisputed champion of windward performance in soft sails, due to its very low drag and high lift to drag ratio. Square rigs do have their advantages, however; they are more efficient when running, where the high lift to drag is irrelevant and the total drag is the most important issue. Square rigged sails are less prone to broaching when running than Bermuda rigs.
On a square rigged mast the sails had names which indicated their position on the mast. The lowest square sail was the course, the next sail up the mast was called the topsail, the next the topgallant sail. Some vessels shipped a fourth, sail called the royal, above the other three. Sometimes a vessel might put out studding sails which would be fixed outboard of the sail on both sides of it. Beginning in the mid-nineteenth century, the topsails and topgallants were each split into upper and lower sails; this allowed smaller crews to tend the sails and provided captains with a greater set of options in choosing which sails to set. Sails are referred to by their mast and then name, ''e.g.'', "the fore topgallant sail", often shortened to fore t'gallant.
Sail characteristics
A square rigged sail is not in fact square, but more nearly trapezoidal, being symmetrical but longer in the foot than the head. Like all sails it is three-dimensional, and its curve or belly means that its foot (lower edge) is not a straight line at all. It is fixed to a spar (the yard) along its head, and its clews (bottom corners) are controlled by sheets, often run to blocks on the spar immediately below the sail.
Modern square-rigged ships are still used for training, tourism and ceremonial purposes.
Types of square rig
Principally square rigged types
★ A barque has three or more masts, with the aftermost entirely fore-and-aft rigged, while the fore, main and any others are square rigged.
★ A brig has two masts, both square rigged.
★ A full rigged ship has three or more masts, including a foremast, mainmast and mizzen, and all masts are square rigged.
★ A sloop has only one mast.
All the above rigs normally carry a number of jibs and at least one spanker, and generally carry fore-and-aft staysails between the masts.
Fore-and-aft rigs with some square rigged sails
★ A barquentine has three or more masts, typically with only the fore square rigged while the main, mizzen and any others are fore-and-aft rigged.
★ A brigantine has two masts: A square rigged foremast and a fore-and-aft rigged mainmast.
★ A square-topsail ketch carries one or more square-rigged topsails (commonly two, an upper and a lower topsail) on its mainmast, in addition to its mainsail, mizzen sail and jibs.
★ A square-topsail schooner carries one or more square-rigged topsails on its foremast. This rig is often simply called a ''topsail schooner'' as topsails above the gaff-rigged sails are a standard part of the schooner rig.
★ A square-topsail cutter or sloop carries one or (less commonly) two square topsails on its only mast, in addition to its mainsail and jib or jibs.
External links
★ The Maltese Falcon, a modern square rigged yacht
★ Sail Training Ships, Square rigged training ships
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