Rake sails and lug sails are among the most distinctive traditional sail types. How they differ in terms of position, performance and manoeuvrability, and why some of these designs continue to influence yachts, cutters and working boats to this day.
Everyone is familiar with the square-rigged sails from Viking ships, Hanseatic cogs and the tall ships of the 19th and 20th centuries. The last fishing boats in Europe to carry square-rigged sails are undoubtedly the Polish barkas. Apart from the lower leech, which is usually cut concave, the square-rigged sail is rectangular, square or trapezium-shaped. It can be wide and low or tall and narrow. As a trapezium, it may be wider at the top or at the bottom. However, the yard to which the upper leech of the sail is attached is always fixed amidships on the mast and, when at rest, lies athwartships. By contrast, all sails that lie athwartships when at rest – in other words, practically all sails apart from square-rigged sails and spinnakers – are grouped under the somewhat peculiar term ‘schrattsegel’.
You can find out more about traditional and alternative rigs at YACHT at The Theory of Shape in Sail Physics, on the subject of Traditional sailing with a large gaff rig and on a modern yacht with Junk rig.
The main advantages of the square-rigged sail are: it performs well on a broad reach and close-hauled, and is also safe when sailing flat on the wind, as an involuntary jibe is impossible. Furthermore, multi-masted vessels with square-rigged sails can set a larger total sail area than with a schooner rig. The main disadvantages of the square-rigged sail are its poor efficiency close to the wind and the cumbersome manoeuvring required when tacking.
The broad jib as a special case on yachts
Some gaff-rigged or full-rigged yachts carry a broad jib. This is simply a square sail used as an auxiliary sail on the foremast when sailing on a broad reach. It is often seen on Baltic Sea yacht schooners. On sailing yachts, a broad jib was often preferred to a spinnaker on long voyages in the past.
A spinnaker can sometimes be set above the broad jib. Often, the upper leech of the broad jib is not attached to the yard along its entire length, but only at three points. The sail is then sheeted in via blocks at the cams – as the ends of the yard are called – and at the centre of the yard, and then trimmed out. To stow such a sail, one simply unfurls it; the yard remains in place. Nor does anyone need to climb up the mast.
On some English deep-sea fishing cutters and yachts, the broad jib was not set on a fixed yard, but on two separate spreaders, which looked similar to spinnaker poles but were mounted higher up and could be folded down when not in use.
On some ships, a tall, narrow yard sail is used as a broad jib, the upper leech of which is shorter than the yard. This sail is always set on the windward side of the yard, i.e. opposite the mainsail. This means that the part of the broad jib that would be covered by the mainsail or schooner sail anyway is omitted. Although this yard sail is set asymmetrically, the yard is still suspended in the centre.
Why lugger sails are more powerful when sailing close to the wind
This is different with the various types of lug sails. With a lug sail, the yard and sail are aligned lengthways along the ship when at rest. The yard is usually not suspended in the centre, but closer to the forward end. Almost always, the yard stands at a more or less oblique angle, like a gaff, higher at the stern than at the bow.
Like all the other sails described, lug sails are also classified as square sails. Every lug sail is more effective close to the wind than a square-rigged sail. Some lug sails even perform better close to the wind than a gaff-rigged sail. There are loose lugger sails, also known as dip-lugger sails; balanced lugger sails; fixed lugger sails, also known as standing lugger sails; and Chinese lugger sails.
Dipplugger sails: strong, but difficult to manoeuvre
The loose lugger sail is known as a dip lugger sail. It was often used on fishing boats in England and France. Its tack is attached a short distance in front of the mast, roughly at the stem head, usually to a hook. The yard also extends a good distance forward beyond the mast, so that a considerable portion of the sail area lies in front of the mast. Consequently, no additional headsail is often set in front of such a sail.
The Dipplugger sail is quite efficient, even when sailing close to the wind. This is mainly because the sail extends in a continuous curve from the bow to well aft, and the mast does not stand in front of the luff and disrupt the airflow, but is positioned at a considerable distance alongside the sail, where it has virtually no effect on the airflow over the sail. This is something this sail has in common with a genoa.
The dip-lugger sail, together with its yard, must always be positioned leeward of the mast. If the yard and sail are on the windward side, the mast presses into the sail and the front part of the sail, like a jib held back, turns inside out and ‘slows the boat down’.
The major drawback of this type of lugger sail is that, when tacking or jibing, the only way to get it onto the correct side of the mast is to luff it off, move the yard and sail to the other side of the mast, and then luff it back onto the new leeward side. Consequently, this sail is completely unsuitable for vessels with a small crew, and tacking in short reaches – for example, in narrow fairways – is practically impossible.
However, on some fishing vessels and other working boats with large crews, this drawback was accepted because of the simplicity of the rigging (short mast, very few fittings, and therefore low production costs) and the pulling power of this sail.
Fixed lugger sail and balanced lugger sail
Manoeuvring is easier with a fixed lugger sail. This sail is cut in such a way that the luff is secured firmly to the mast, just as with a gaff sail or a topsail, but only the luff, not the entire leading edge. As with all lug sails, the yard here also extends forward beyond the mast. However, the area of sail in front of the mast is much smaller than with a loose lug sail.
The fixed lugger sail also sits better when the yard is to leeward of the mast. The upper part of the sail then does not flap out as far, so it twists less. Unlike with the dip lugger sail, however, it is not absolutely necessary to shift the sail to the new leeward side at every tack. On short cross-wind tacks, you can certainly save yourself the trouble. You then tack in exactly the same way as with a gaff sail or topsail.
However, to ensure the sail sits perfectly, you should trim it when tacking or jibing. To do this, reach into the luff or, if you can reach it, directly onto the lower tack of the yard, pull it aft so that the yard is vertical, and then let it slide forward again on the correct side of the mast – that is, on the new leeward side – or push it there. It sounds more difficult than it is. Anyone who has ever sailed on a naval cutter or a youth cutter will know what I mean.
Apart from these cutters, the fixed lugger sail is also used on merchant ship lifeboats and yacht dinghies. The Zeesenboote of Mecklenburg-Western Pomerania fly it as a mizzen sail; otherwise, it was rarely used on fishing boats in Germany.
The main advantage of the fixed lug sail is that it allows for a cost-effective rig with a short mast. It is also quick to hoist and lower, as, unlike a gaff sail, only one halyard is required. It is easier to handle when manoeuvring than the loose lugger sail. It also offers good sailing characteristics; the steeper the yard is set, the better it performs close to the wind. It is an ideal dinghy sail, as the mast and yard can be stowed in the boat without protruding, unlike with a full rig. Disadvantages only become apparent with larger lugger sails; the yard, which is quite long – particularly when set at a fairly steep angle – is heavy and unwieldy.
The balance lug sail is similar to the loose lug sail, but has a boom which, like the yard, extends forwards past the mast. The head of the sail is attached to the front of the boom. The balanced lugger sail is not normally reefed. As it is cut flat, the mast exerts only minimal pressure on it when the sail is on the windward side.
This sail is often used without a headsail, i.e. as a cat rig. It was and remains common in England and France, as well as in the eastern Mediterranean, but was scarcely used in Germany and Scandinavia, apart from on a few pleasure craft around the turn of the century. The advantage of this sail is its relatively large sail area on a short mast, similar to that of a loose lugger sail, but without the difficult handling – no dipping, no shifting.
One drawback is that the balance lug sail does not sit optimally on the windward side of the mast, even if it is cut very flat, and that a jib, if used at all, tends to snag easily on the protruding boom when tacking. The drawback that the yard becomes rather unwieldy with larger sails applies here just as much as it does with the other lugger sails.
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Tradition or practicality: which of these old designs seems most convincing from today’s perspective – the sturdy square-rigged vessel or the more efficient lugger? Share your thoughts in the comments.