Sailing ships are still being built, but square riggers are a thing of the past. Why?

Did fore-and-aft rigging prove superior? If so, why not earlier?

Does it have to do with the disappearance of large sailing ships as opposed to small pleasure craft? If so, why is style of rigging related to size?

Are square riggers inherently labor-intensive? If so, could a square rigger be practical today with automation?

  • Actually it is still done (e.g. the Maltese Falcon) – Manu H Mar 13 '19 at 10:23
  • @ManuH that was done to emulate 19th century ships on purpose, and is one of the "worlds most complex" ships though. Do you have a less unique example? If that's it, i wouldn't say it's still being done. Just that it has been done recently. – user32121 Mar 13 '19 at 19:55
  • Amerigo Vespucci, Christian Radich, Gorch Fock -- the considered replacement for the latter would also have been a square-rig. These are training ships though, where the comparatively large crew requirements of the square rig are not a factor (indeed, help in keeping all the cadets busy). Sailing ships that size aren't built often overall, so the sprinkling of square riggers should suffice for "still being done" IMO. – DevSolar Mar 14 '19 at 18:22

Let's first recap points of sail.

On a dead run (and for most rigs also a broad reach) it is only possible to travel at slightly less than the wind speed. This is because the vessel is being powered only by wind drag, with no lift component. However in a light breeze even that can be difficult, so it is imperative to catch of much of that light breeze as possible - especially at heights where reduced surface friction makes the breeze slightly greater.

Square rigs are the best at catching light breeze at maximum height above the water. (A square sail at the top of a mast, hanging from a yardarm, captures 4 or 5 times as much wind as the triangular head of a fore-and-aft sail of the same height.) For tasks such as long-haul cargo transport over distances at which one can mostly sail on a run or reach, the square rigger is perfect. Trade Winds or Westerlies are used depending on one's direction of travel.

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However square rigs are only capable of pointing to within about 60 degrees of the wind, and that only in light to moderate breeze

Next, note that as a vessel points higher into the wind there is more and more wind force pushing the boat over into a heel. In a dinghy this can be countered by moving the crew weight to the gunnels or even hiked out, as here:

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A heavier, deeper, keel also assists in countering the heel force (in addition to improving the pointing). However a sailing vessel with a deep keel cannot use a shallow harbour; and keeping the crew on the rails is impractical on long expeditions, for obvious reasons.

When competitive day-racing began around the turn of the 20th century, the triangular race-courses favoured made upwind-pointing (and, for smaller boats, the ability to plane) critical design decisions. This resulted in the preponderance of fore-and-aft rigs, such as lateen and sloop, on these boats.

Returning to the question - production of square-rigged ships ceased when their primary use - long-haul cargo transport - was superceded by coal and then diesel-powered vessels. Their poor upwind handling was the primary reason why that sailplan was never popular for day-racing. It is unlikely that crew requirement was critical in that regard, when one looks at the huge ships that competed for the America's Cup races in the late 19th and early 20th centuries:

A final note on the reason for favouring triangular race-courses in day racing: Because the upwind boat is always favoured, due to the ability to cover the opposing boat, interfering with its wind and slowing it down. This advantage then alternates between the leader(s) headed upwind and the trailer(s) headed downwind.

A classic example of this was the 1983 America's Cup best-of-seven final. Despite having a significantly slower hull, Dennis Connor managed to win three races and force a seventh through superior helmsmanship. The final upwind leg, with fifty real and faked tacks, is regarded by many as the epitome of fine sailing.

On these race-courses, a fore-and-aft rigged ship compensates for the absence of square-rigged sails by employing a spinnaker: A (usually brightly coloured) over-sized balloon of a sail designed to capture as much wind as possible, as high up the mast as possible. It employs a spinnaker-pole as a temporary yardarm to achieve these aims. In that sense, the square-rig is not truly dead - just modified.


Rebuttal of the claim made below by another author. From the link above, here repeated, to the Royal Yachting Association's description of Points of Sail:

Beam Reach – This is the fastest and easiest point of sail. The wind is on the side of your boat (beam) and you’ll sail with your sails out half way.

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Run – With the wind directly behind you this is the trickiest point of sail to steer as it can be quite unstable. On a run your sails can be let out on opposite side of the boat to catch the wind (sailing goosewinged) or a big sail called a spinnaker can be set.

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Note the point being made that beam reach is the fastest and easiest point of sail. Also that a run ... is the trickiest point of sail to steer as it can be quite unstable. Their words not mine.

The answer below claiming otherwise is incorrect.

The reason is that at point of sail below a beam reach there is very little (broad reach) to zero (dead run) lift force possible from the sails. The boat cannot travel faster than the wind because at these points of sail it is impossible to keep the sail full except when travelling slower than the wind. In an even slightly unsteady breeze one cannot even attempt approaching the actual wind speed because if a lull ever empties the sails, this immediately halts the boat by collapsing and reversing the sails.

At very low windspeeds it is imperative to never lose your momentum, and come to a dead halt. One might have to wait for a gust, perhaps a substantial one, to break the skin friction with the water and get moving again. Sailing at a dead run or broad reach in a light, unstable breeze threatens this constantly. This is why sailors so dreaded the doldrums and horse latitudes in the age of sail: not only was the wind light, one had to take such care sailing to it, for very long stretches of time. They would be spending the entire day scrambling up and down the rigging (gently, to not disturb the sail trim) to trim the sails so as to never collapse on a lull or shift.

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    @BenCrowell: Absolutely. The Portuguese in the late 1400's realized that this was possible using Trade Winds and Westerlies. – Pieter Geerkens Mar 13 '19 at 15:09
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    @BenCrowell: A square sail at the top of a mast, hanging from a yardarm, captures 4 or 5 times as much wind as the triangular head of a fore-and-aft sail of the same height. Of course everyone makes their masts as high as strength of materials and vessel size allow. – Pieter Geerkens Mar 13 '19 at 15:13
  • Perhaps add a word on the crew requirements? Square rigging requires an awfully large crew complement to operate, when compared to Fore-and-Aft... – DevSolar Mar 14 '19 at 18:18
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    You can sail any ship with an emergency crew complement. But when you want to tack, shorten sail in bad weather, or do the kind of careful low-wind trimming you mentioned, having only the emergency crew will get you into trouble. And the "normal" crew requirements for a square rig are larger than for a fore-and-aft or lateen rig -- unless you're looking at a high-tech fully automated ship, you need men on those yardarms (dangerous!). I don't say it's "the" reason, and I don't say it "needs" to be in the answer, I just wanted to raise the point for consideration. Very good answer either way. – DevSolar Mar 15 '19 at 8:24
  • @DevSolar: You are correct. I will amend a bit later this am. – Pieter Geerkens Mar 15 '19 at 11:14

Why did people stop building square-rigged ships?

Short Answer:

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While single sail square rigged ships like the Roman's, Greeks and Vikings used disappeared, because they they could not match the efficiency, speed and flexibility of multi sail rigging. Multi sailed ships which replaced them continued to use square rigging. Square rigged ships were with us until coal and steam ships entirely replaced sails in the early 20th century. This is because although not as flexible at different points of sail, square rigging remains the most efficient configuration for running directly down wind and thus for large heavy ships remained the primary sailing configuration until sails disappeared from commercial and military ships in favor of exclusively steam ships in the early 20th century.

Detailed Answer:

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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, or square, to the keel of the vessel and to the masts.

Square rigged ships are the most efficient configuration of any alternative rigging; however, this rigging looses it's advantage when sailing at different points of wind beyond directly down wind. A ship like the HMS Victory built during the golden age of sailing ships, largest and most numerous sales were square rigged, and those sails hung on the Foremast, Mainmast, and Mizzenmast. But she carried as many as 37 different kinds of sails to augment or even replace the large square rigged sails depending upon the wind and the desired coarse relative to that wind. What set her apart from the early Greeks, Romans or Vikings wasn't the square rigging as all used square rigging. What set a ship like the victory apart was that it was designed to run as efficiently as possible regardless of the wind or point of sail. She could add or reduce canvas and type of canvas to suit the sailing conditions, but the largest and most numerous sails were still square rigged.

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HMS Victory built 1758, pictured 1900

Heavy capital ships in the worlds navy's continued to use square rigged sails after the age of coal and steam ships had arrived.

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USS Atlanta in 1884 showing the hybrid configuration of square rig and steam. A square-rigger can be seen in the background.

The USS Atlanta was a hybrid battleship. It augmented it's steam engines with sails to improve it's range and speed.

The most efficient configuration for a sailing ship is flat not healed over. Healed over ships by definition are wasting the power of the wind pushing the boat sideways (healed). They are also by definition spilling wind out of their sails and reducing sail surface area.. The most efficient configuration for sails is with the largest surface area of your sails perpendicular to the wind catching as much wind as possible. For both of these reasons multi sailed square rigged vessels like the HMS Victory and the USS Constitution were present when sailing technology as the primary propulsion for commercial and military ships reached the height of it's technology.

  • Do you understand any of the sailing terminology you have used? The statement "The most efficient configuration for sails is with the largest surface area of your sails perpendicular to the wind catching as much wind as possible." strikes me as absurd, because by definition it is where lift force from the sails is zero. The most efficient point of sail is actually a beam reach (more or less), where fastest speeds are possible for a given wind speed. This answer is simply wrong in all its details of sailing. – Pieter Geerkens Mar 14 '19 at 17:42
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    Anyone who doesn't believe me - Google "most efficient point of sail". The answer will be "beam reach". – Pieter Geerkens Mar 14 '19 at 17:45
  • From my link above to the Royal Yachting Association's outline of [Points of Sail]()rya.org.uk/newsevents/e-newsletters/inbrief/Pages/…): "Beam Reach – This is the fastest and easiest point of sail. The wind is on the side of your boat (beam) and you’ll sail with your sails out half way." – Pieter Geerkens Mar 14 '19 at 17:48
  • Running and Broad Reach are the least efficient points of sail, not the most efficient, precisely because lift force is zero. The boat is constrained to travel at less than the wind speed, else the sails collapse and immediately brake the boat, forcing it backwards, – Pieter Geerkens Mar 14 '19 at 17:50
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    Tonecheck please; we're all committed to high quality answers, but we're also all committed to mutual respect. – Mark C. Wallace Mar 14 '19 at 18:38

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