Superyacht or Tall Ship?
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From a distance, Maltese Falcon looks like a tea clipper from the days of Cutty Sark and Thermopylae. It’s only when you get closer that you notice that there’s no gap between the sails on each mast, that the yards are curved, and that her masts are unstayed.
She was built as a proof-of-concept for DynaRig, a system originally conceived in Germany in the 1960s as a means of powering cargo ships after the first oil crisis. It was abandoned because there was no way at the time to make the rig light enough.
The man with the imagination and drive to get her designed and built was ‘Valley Boy’ Tom Perkins, who once worked for Silicon Valley company Hewlett Packard, then created the groundbreaking venture capital company that helped launch companies such as Google and Amazon. So perhaps it’s not surprising that, even in his mid-70s, he was the man to see that Dynarig’s time had arrived - thanks to modern materials such as carbon fibre - and to have the skills and the drive to get his proof-of-concept built.
First, he bought a clipper-like steel hull that had been on Fabio Perini’s hands for a while, and commissioned Perini to modify it for his purposes - for a start, the hull had to be braced to carry three unstayed masts and the gear to rotate them.
Next, he built a manufacturing facility next door to the Turkish Perini Navi yard, in which he built the rig, since neither Perini nor anyone else had the necessary equipment or personnel. After Falcon was built, he gave the facility to Perini.
There are several photos of Maltese Falcon in the public domain, (take a look at Gaetan Lee’s view on flickr.com) some with and some without sails set, but the only ones I have seen which show clearly how the sail-setting system works are in the January 2007 issue of Yachting World, which you can buy in electronic form from Zinio . The middle of each sail is pulled by extra boltropes towards the mast, where it is furled onto a concealed drum in the forward section of the mast. The leeches draw in towards the centre and end up rolled on the drum. This system allows the unfurled sail to be set clear of the front of the mast, as a clean arc-of-a-circle aerofoil.
Perkins says that the royals (the top sails, as in a traditional square-rigger) account for up to 40% of the heeling moment. At first, this sounds unlikely, but I think I can understand why.
Wind velocity increases with height quite rapidly over the first few hundred feet - try flying a big kite and you’ll feel the proof after you launch it and start making it climb. This means that apparent wind angle at the mast head is greater than at deck level.
Watch a traditional square-rigger on a reach - you’ll see the upper yards squared off more than the lower ones if her sails are properly trimmed. She has loose-footed sails which can be set with a twist, but Dynarig sails can’t do this. Even if the yards were allowed to rotate independently about the mast, the sails couldn’t take the resulting twist - both head and foot boltropes are firmly held by the upper and lower yards and the cloth doesn’t stretch.
This means that every sail on a given mast, from course to royal, is set at the same angle to the boat’s centreline. In turn, this means that you have to trim the yards so that the royals are just below their stalling angle of attack and the courses will be at quite a low angle of attack - hence the royals are generating more power in proportion to their area than the courses are.
So it’s true that taking in the royals will drastically reduce the heeling moment of the rig, but this is partly because the remaining sails are under-trimmed. After taking in the royals, Tom probably re-trims the sails and adds back a bit of heel…
