Aoraki build

August 1994 - September 1996

I was wanting to build a bigger boat, as Deirdre and Malcolm had grown too large for our little 8 foot (2.5m) pram dinghy. What I really liked the look of were Dutch boats seen on a visit a few years earlier, and I'd seen a little one which would have been good to copy. However, any monohull big enough could not be car-topped (unlike the pram), so I was getting resigned to the idea of towing and launching off a slipway. Then I saw pictures and reviews of Wharram catamarans in Practical Boat Owner, and realised that a cat that could be dismantled could also be car-topped.

At that stage I didn't know anything of the details of how a Wharram cat was put together, but still made some rough drawings based on Wharram shapes that looked good, and looked as though they could be built easily. After a lot of thinking time, I made the drawings for Aoraki. Only then did construction start, with smaller bits that could be made indoors.

[beam internal (25kb)]

The beams are box girders with internal webs for extra stiffening. They were tested for flexure by using different weights (people!) and matched the mechanical calculations well. West System epoxy and microfibres was used throughout the construction of Aoraki; all parts are also epoxy coated before painting. Only the keels, stems, skegs and bottoms of the rudders have a fibreglass sheath for protection during beaching. The beams were built first, in August 1994.

[hull - building (24kb)]

The hulls were too large to be built indoors so had to be built outdoors on our balcony. Building with epoxy in the open air is a bad idea unless you have guaranteed dry weather and enough warmth. This is the first hull, in August 1995.

The second hull was completed in September 1995. Here it is, with suitable weights holding down the aft deck during expoxy curing; the first hull sits beside, inverted, and already coated. Note used rollers used for coating sitting in sliced-up plastic milk bottles! If too much epoxy is left in the rollers, it gets so hot in curing that the rollers start to smoke!

[two hulls (20kb)]

By October 1995 the size of the boat could be seen by putting the beams on to the two hulls; there was just enough room to do this on the balcony. The hulls then had to live there, covered in Bradshaws' best tarpaulins, for the winter. Indoors, some of the smaller components, such as the plaform sections and rudders, could be made over the winter.

[first part assembly (23kb)]

The summer months in 1996 were spent painting and finishing off bits and pieces ready for fitting out. The hulls were then taken through to near Oban on the west coast of Scotland, where we have done most of our sailing. By 13 September 1996 we could put all the hardware together, and were waiting for the sails so that the rigging could be finished.

[first full assembly (18kb)]

[sails up (14kb)]

The next day (14 September) we had the sails, so the boat could finally all be put together on land. Wonderful! We were very pleased with the result and couldn't wait to get her into the water. Sails were made by our local sailmaker, Owen Sails, and they're really good.

Here's the works at the aft beam. All the sheet jam cleats are on the beam, together with jam cleats for the mainsheet position control lines. Jib sheets are red, mainsail sheet white. The tillers, tiller bar and platform are not varnished, but coated with Burgess Wood Seal - wonderful stuff. The platform sections (3 of them) are held down on the beams with loops of shock cord. With the platform on top of the beams, there's a lot of clearance above the wet stuff, so Aoraki is pretty dry unless things start to get very rough. Note that the rudders are lashed on, just like the Wharram Tiki designs.

[stern end (19kb)]

[mainsail tack (24kb)]

The halyards can be seen here emerging at the bottom of the luff pocket on the main (another feature of the Wharram Tiki designs). The different colours are a great help, providing you always fasten them on to the same things at the other end. Yellow is usually the gaff throat halyard, blue the peak, red the jib halyard ('cos it matches the jib sheets!).

[mainsail head (14kb)]

Here's the top end. The gaff is also in a pocket. You can also see that the shrouds are not wire: they're prestretched polyester, and work very well on a small boat like this. Much nicer to handle than wire. The top ends of the shrouds simply have loops in them which go over lugs at the top of the mast.

On 15 September 1996 we finally got Aoraki into the water. Here we've returned to the beach to get the gaff halyards tightened up; they need to be really tight to get the sail to set properly.

[on the water (24kb)]

Now some pictures under sail; first the stern ...

[stern sailing (21kb)]

... then the bows ...

[bows sailing (17kb)]

... and here's more detail of the rudder. The hulls slice so cleanly through the water, there's not a lot of wake left behind.

[rudder sailing (25kb)]

[first assembly (17kb)]

Finally, skipper and crew (for that day) out on the slip. Skipper actually wearing a PCA sweatshirt; nice and warm for September sailing in Scotland. At that time we had only little boxes that fitted under the skegs/rudders, with wheels from an old baby buggy, to move Aoraki around. We now have much better boxes with big wheels that go amidships under each hull, so it's easy to move the whole boat, like trundling a big wheelbarrow.