BlackIce IOM Progress

Prototype work progressing in QLD...

Octave Marblehead First Sail

Nice conditions for a shakedown. Let the observations begin!

Octave Marblehead Prototype Rigs: Bunjees

A beautiful precision job and a snazzy detail by Ray Joyce.
The idea is to incorporate a bunjee into the Dyneema 'limiter' strop for the automatic speed/height 'moding' adjustment on the swing rigs.
A lesser mortal would have tied the bunjee separately, but this would have left an untidy loop of Dyneema when the limiter was slack.
Here is Ray's description of the procedure:

I did a few trails and decided not to include tying the elastic within the fixing knots because of it being too bulky. I found that with a piece of elastic captive within the 
spectra it did not need much encouragement to stay where it was, so came up with a solution which seems ok. 

The pics show. 

You'll see that at each end I passed the elastic in/out/in then through the 
spectra for 50mm then out/in/out. I then whipped each end over the end 4mm sections.

Octave Marblehead Prototype Rigs Progress

Neat detailing for jib boom adjustments. Neatly executed by Ray Joyce.

BlackIce IOM in Series Production

Octave Marblehead Prototype Rigs: Sail Controls

Very neat execution by Ray Joyce of an experimental 'mode' control system.
It closes the exit of the mainsail automatically when the boom is on centreline.

This allows a standard 'open' setting for acceleration and reaching to change into 'pointing mode' once the boat is up to speed going upwind.

The standard four rigs are specifically designed for Octave by Carbonicboats.

Octave Marblehead Prototype Rigs: Progress on Spars

Carbon/foam sandwich jib booms were chosen to maximise jib efficiency and allow 'finite' adjustment arrangements using notches and pin/hole systems. The jib boom swivel line goes through a fairlead in the top skin of the yard and is anchored through the bottom skin. This is to maximise length for the required twisting of the line. Since the jib only rotates through approximately 60 degrees, this solution is adequate and a mechanical swivel can be eliminated.

Front fairings for the jib yards are lightweight plastic taken from knitting needles.

We are having similar plastic fairings machined so get in touch if you want to clean up the airflow at the front of your jib yards. 

The final two pictures are of the backstay detail. Strops top and bottom are glued in place to eliminate chafe. The actual wire is mono filament fishing line and adjustment is via a turnbuckle at the aft end of the boom.

BlackIce IOM Tooling Progress

Successful mould lamination and release under contract in QLD. Result!

A Class Cat Carbon Boom: Mid Boom Sheeting

Only by learning to sail a boat type firsthand...

The experimentation continues. This time to get a handle on the pros and cons of mid boom sheeting.

As a designer my instinct is to prefer end boom sheeting off the traveler. It is mechanically more direct, doesn't put large bending stresses on the boom, and does not use the trampoline (stretchy) as part of the sheeting system.

But there is something to be said ergonomically for mid boom sheeting so we should try it and then make an informed decision.

Assuming the boom tube is stiff enough, this solution gives the flexibility of switching systems with virtually no parasitic weight. It consists simply of a foam and carbon 'stopper' to locate the mid boom block strop and a similar stopper to locate the boom end block strop.

The sail strop sits inboard of the boom end block to accommodate shorter footed sails.