Perforated Sails.
At first glance a sail with a hole in it would hardly be considered superior to a sail without one, yet sails with holes in them, or perforated sails, as they were called, became quite popular with the most experienced of our sailing ship skippers in the early nineties.
Perforated sails were said to be the idea of an Italian shipmaster in the eighties. This Italian captain’s theory was that a cushion of air or dead wind, as he called it, was collected in the belly of every sail, and acted as a buffer, thus preventing the sail from receiving the whole strength of the wind. He advocated making a hole in the centre of the belly in order to allow this cushion of air to escape, and allow the true wind to blow against the surface of the sail. An important point was the proper placing of these holes; in fore and aft sails they were cut about the centre of the belly made by the clew; the holes in square sails were also cut near the clews, but they were also cut higher up in the sail on a line from the clews to the bunt: topsails and courses generally had the four holes and topgallant sails and royals only two, one in the lower part of the sail towards the clew on each side. These holes were from 5½ to 6 inches in diameter and roped with grammets.
It is easy to understand that this system was more advantageous when one was close-hauled than when running free. But even when running free many shipmasters claimed that it had its merits and held that, though wind certainly did escape through the holes, it was mostly dead wind and even then was caught up again—the mizen by the main, and the main by the fore, so that in the end there was very little real wind that did not do its work in sending the ship along.
A further advantage of perforated sails was their aid in spilling the wind out of a sail when the sail had to come in in heavy weather. The advocates of the holes claimed that they prevented a sail from ballooning up over the yard, and made it very much easier to muzzle and put the gaskets on.
The perforated sails were also considered very useful in light airs and calms, because on the calmest day there always seemed to be a draught through the holes, and this kept the sails “asleep” and stopped that irritating flogging of canvas against the masts which is so trying to a skipper’s temper and also constantly necessitates the hauling up of courses in the doldrums.
Captain Holmes, who always used them in the Cimba and Inverurie, wrote to me that he considered them specially valuable in light winds, and he did not adopt perforated sails without testing their efficiency in every way he could.
He even had sand bags made to fit the holes, and thus was able to test his sailing when in company with another ship, first by seeing how he did with holes, and then filling up the holes with sandbags, by seeing how he altered his bearing when without holes.
By this means he proved the benefit of the holes very clearly once when going down Channel.
The Cimba was in company with another outward bound ship of nearly the same speed; and it was found that as soon as the sand bags were put in the holes the Cimba began to drop astern, whereas, with the holes open, she went ahead. Captain Holmes also tied a rag on the end of a stick, and held it up to the holes, and even in very light airs the rag was sucked through the perforations. In this way with a handkerchief on the end of a long rod, he tried to find out the result of the holes on the crossjack, by walking it all over the after part of the sail. And he told me that the handkerchief flopped stupidly about in the dead wind until it was abreast of the holes, when it at once blew out straight.
Captain Pattman, of Loch Torridon, adopted perforated holes in 1892: Captain Poppy used them on the Aristides, and Captain Cutler, when he took over Port Jackson, had her sails cut for holes, and his successor continued to keep them in the sails.
All these four captains were noted passage-makers, and unless the perforated sails had had very certain advantages, it is hardly likely that they would have adopted them.