Tuesday, 26 May 2020


Welsford’s plan for the Navigator shows a rudder with an up-haul and a down-haul. I’m not too keen on the idea of down-hauls, as if I hit things and the down-haul doesn’t release, then bad things happen.

So I figured I’d omit the down-haul, and instead weight the rudder with lead, similarly to the centerboard. Hey, every little bit of tighting moment has to help some, right.

This time with the lead, I just went and bought a pile of lead flashing. I melted it in an old cast iron pan outside, and poured it into a mold made from steel and aluminium.

I cut that into the rudder core, made from four 12mm thick jarrah planks.

And then glued on cheeks made from Tassie Oak, roughing it to shape with the bandsaw, power plane, and jack plane, then 40 grit in the sander.

I’ve added a pivot point (16mm hole with 12.7mm bronze bushes), and an eye for the up-haul, which I think will have to be 2:1 on account of the weight.

Tuesday, 5 May 2020

I can stop any time

A picture of my frypan collection.

They’re all Le Creuset, mostly vintage. Two of them have had the enamel stripped and replaced with seasoning.

And the omelette process. We start with my favourite pan, a 23cm Le Creuset with the enamel stripped, seasoned with lard. When the seasoning is just so it’s a little glossy.

Ingredients for a basic omelette are a bit of butter, two eggs, some finely cut spring onion and a little grated cheddar cheese, with salt and pepper.

Chuck the butter in the pan and heat it until it’s foaming. While that happens go at the eggs lightly with a fork, and add salt and pepper.

Add the eggs to the pan when the butter quietens down. Then chuck the spring onion on top. Move it around a little with a fork to get the folds, and allow the runny egg to run onto the bare pan.

I like to add a teensy bit of grated cheese, which I melt with a torch. I used to pop it under the grill for a few seconds, but the torch is much more controllable.

Finally fold it in half with a fork, and slide it onto a plate.

Et voila. Bon apetite!

Sometimes I just chuck in whatever’s in the fridge. Pepperoni, chorizo, cherry tomatoes, mushroom, etc. But that usually ends in a thicker omelette that won’t fold.

Sunday, 3 May 2020

Doodles towards a new boat

So these are the constraints I'm working to:

  • Beam of around 2300mm, to allow the boat to be stored behind my house (the gap between the fence and my garage is 2400mm). This will also allow for trailering without wide load placards, being under 2400mm.
  • Length of around 6000-6500mm. This is a bit more vague, as there's no specific constraint here, but the 6m length tends towards a 2300mm beam, so this is it.
  • Maximum draft of around 800mm. More than this makes trailer launching at boat ramps really hard. Indeed even launching a boat with an 800mm draft will be hard. Stability and cabin room is however directly related to draft, so there is a strong push to maximise draft at the expense of trailerability.
  • Maximum weight of around 1800kg unladen. The tow vehicle I am considering has a maximum towing weight of 2500kg. If we subtract 700kg for trailer, we end up with 1800kg for the boat. Stability constraints again push us upwards here, and trailerability constraints push us down. I think something around 1400-1500kg is probably reasonable. This implies a displacement of around 2000kg.
  • As much sailing ability as I can get given those other constraints. Ideally I want something I can sail across the Great Australian Bight in, so some measure of blue water capability.
Some of these constraints are directly contradictory. Trailerability comes at the direct expense of blue water ability. I think I can find a happy compromise that ends up in a boat that's enough different to Elena to make the exercise worthwhile.

I'm working on the premise of a 6m LOD, 2.3m beam, 0.6-0.8m draft boat with centerboard mounted in a trunk below the cabin floor. Katie comes pretty close, but the draft is perhaps a little on the shallow side, at around 0.48m board up. Pretty-much everything that's designed without a board has a draft of over 0.9m, which I think is just a little deep.

To find a better compromise, I thought I might try developing my own hull shape. I started with the table of offsets for Buzzard's Bay by Herreshoff, as published in Sensible Cruising Designs. I found the table of offsets to be surprisingly lumpy, so abandoned any attempt to stick to the table of offsets and instead just started drafting lines in Sketchup. The process was first to draw a profile (face), and overall plan view, to constrain LOD, beam and draft. The shape is similar to Buzzard's bay but I brought the bow up more vertically above the waterline, and increased the radius of the turn of the bilge, giving the rabbet a hard inflection rather than a smooth curve.

Then I drew waterlines and stations, got them to line up, drew buttocks, found they were miles off fair, edited the waterlines, edited the stations, edited the buttocks, and went around the loop half a dozen times, until the waterlines, buttocks and stations all intersect with errors of <1mm or so. I think the shape is reasonably pleasing.

Here's the profile:

Draft ended up 760mm, which is just shy of my maximum of 800mm. LOD is 6380mm. Beam is 2300mm. There is 750mm freeboard at the bow, dropping to 470mm amidships and raising again to 600mm at the transom.

The plan view is below:

After the issues I had with Elena getting the garboard plank around to the bow with a strong concave section, I kept the bow mostly convex, even down at the garboard. There is s reasonably strong turn to the bilge at the stern. This gives a nice shape to the transom and I think will also provide additional stability.

The rear view is also shown:

I haven't put any tumblehome in to the stations. I'm wondering if perhaps bringing the gunwales in a tad might make for more strength to the form, but also want a decent amount of room on deck to be able to get past the cabin, when I design one in. I may change things around a bit as I keep going.

Finally the quarter-view. I haven't sheeted the hull in sketchup, so it's just a bunch of lines.