Working with Classics in an Aramid Age - Part 2 of a look at 3Di
by Richard Gladwell on 28 Jun 2012
Continuing Sail-World's tour of the North Sails' Auckland, NZ loft looking at the use of 3Di with classic J class yachts, Volvo Ocean Racers to club fleets, plus many other interesting aspects of the traditional art that now heavily overlaps with science.
Lionheart - Day 2 - J class UK Series, Falmouth. She is running a 3DL job and 3Di mainsail - both of quite different constructions, as well as the obvious colour difference J Class Association
North’s production isn’t limited to the grey of 3Di. Often they will have four materials on the loft floor – 3Di, 3DL, Dacron and spinnaker nylon.
'The size of the sails being built has required some original thinking in terms of machinery, says Production Manager Matt Smeaton. 'One of which is the rotating sewing position. When we are working on a big sail, rather than having to lug the whole sail around to get it through the machine, we rotate the machine around the sail.'
In Nevada, they have taken it a stage further, with a sewing machine which has a bed rolling along the floor. The sail stays still and the machine moves down it sewing as it moves. 'It means that one sailmaker can work alone on a sail weighting 400kg,' says Smeaton.
Although in an oldish building in Auckland’s traditional waterfront district the loft has 2800sq metres of area on the main floor, with a 60 metre floor length – enabling a J class main to be stretched to full length
Norths also run two shifts – starting at 7.00am and with the second shift starting at 4.00pm and running through to 2.30 am.
'We have worked the two shift system since 2000, running Monday through to Thursday,' says Smeaton.
'Floor space is a premium and a good way of running that efficiently is to have fewer number of sailmakers on the floor at one time. We could have the same total number working on the floor, for just an eight hour day, but not as much work would get done.'
Including the small boat loft there are 24 sailmakers employed at Norths NZ, plus those in the service loft. Six sailmakers work on the late shift. A handover is done at each shift change, and work continues from one shift to the other - working on the same sail.
Shifting the sails requires some interesting techniques. Being adjacent to the Viaduct Harbour and the superyachts means that sails can be carried manually down the street by a team. Or, they can be loaded onto a long trailer or a truck is used.
A J class mainsail typically weighs in at a mere 400kg. 'Some of the mega yacht sails weigh almost a tonne. So cranes are often required at the dock to lift them into position on the boat,' explains North Sails Designer Burns Fallow.
A long plotter
Cutting the panels for the massive 1000 sq metre J class spinnakers are another challenge.
At the rear of the loft is a 22 metre long plotting machine. The third plotter Norths have used – since the first was installed in 1988.
The spinnaker cloth is laid, held onto the bed with a vacuum, and each panel is individually cut, directly from the computer assisted design program.
There’s over 2.5km of cutting to be done by the plotter to shape the 450 panels that go to make up some of the largest downwind sails.
Keeping track of those panels is not easy. Behind the plotter are two long belt of numbered pouches – an idea from Norths in Europe. 'Seems obvious now, but it took us 25 years to figure that system out,' says a bemused Smeaton.
As each spinnaker panel is cut it is rolled, numbered and put in its pouch. There’s one row of red pouches, and a second row of blue. The difference being that while one sail is being sewn, the second can be cut on the plotter. The pouch system avoids time lost through having to locate the next panel from a pile.
Despite its 22metre length, the plotter is something not long enough, with some of the J class spinnaker panels being over 35 metres long – requiring them to be cut as two and then joined before being inserted in the spinnaker panel jigsaw.
Kites and One Designs
Upstairs is the One Design loft handling Olympic class sails, Optimists and small keelboat. And alongside that is the Kite division.
'Norths have built over 100 kites for a German company called Skysails’, says Fallow.' Initially these were to be used with ships, but now they are also going to be made available for dismasted yachts'
It’s an emerging technology, with the kites being designed in Germany and assembled in New Zealand. The kites can sail at 60 degrees to the apparent wind. 'You can’t sail into the wind, but you can go somewhere,' says Fallow.
Even a relatively small 160sq metres kite, generating 12 tonnes of pull on a large coastal freighter will save 15-20% on fuel cost. Double the kite size to 320 sq metres and the pull goes up to an impressive 20 tonnes.