Plugging Away

Bamboo continues to be the hinge of Aluna’s propulsion system. It stretches the sailcloth out into the wind and is supposed to hold them there in a certain shape. This implies quite a bit of strength and stiffness, which bamboo is exceptionally good at. It is so stiff for its weight and diameter that only the most modern synthetic materials can come close to matching its properties. You might remember that this summers fierce Southeasterlies managed to bring those properties to its knees and break my mainsail spar not only once but twice. This meant that Aluna was deprived of her fair weather sail and had me looking for a replacement spar.

As happens so often here in well-mannered Northland friends come to your aid from all directions at once. Even before heading down to Auckland almost two months ago Peter donated two of his marvelously straight bamboo culms, which were cut green and have since then been drying slowly over at his magic little kingdom across the river. It will take a total of at least six months of pampering to get them to the point where they will have dried slow enough to avoid any splitting. In order for them to be encapsulated in epoxy, reinforced with fiberglass and painted to protect them from the sun they need to be thoroughly dry. And this will definitely not happen before we have to head out into the big blue again to escape the fast approaching winter. For our upcoming trip to Vanuatu by the end of this month we need a quicker solution!

Enters Ted, who caters to most any need a cruiser can have with his ingenious engineering genius here in Opua, coming up with solutions where others stand for hour scratching their heads and wiggling their toes. Those solutions go from the outrageously brilliant to the simply unusual and end up most always being very straightforward and practical. My usual reaction to his suggestions is a perplex ‘why haven’t I thought of that!’, so when he suggested using aluminum tubing for a quick replacement spar the little ethnic pride that was given to me at birth cringed and squeaked violently, but I had to listen. Instant engineering computations in his amazing brain had come to the conclusion that the resulting spar, made up of two 5 meter sections joined by a sleeve of a slightly larger tube would come out to be lighter by a couple kilos than my bamboo spar. It would be dead easy to assemble. Everything could be done most probably in a single day. But it came at a cost. For most people three to four hundred dollars is a miniscule amount of money, which can be spent without any second thoughts. It is amazing how cheap aluminum has become. But in our limited cruising economy it would rip a good chunk of the little fat our cruising kitty has been able to accumulate over the last year and a half out of existence and leave a gashing hole in our financial portfolio. So it all ended up where many a brilliant idea expires: in the dungeon of economic unfeasibility.

The spar had broken neatly at the point where the halyard attaches it to the tip of the main mast. When bamboo breaks it does not shatter like wood. Its resilient longitudinal fibers remain intact but separate from each other at the moment of failure. That separation typically ends at the nodes to either side of the break. This meant that the pieces of bamboo left over from the accident were more or less intact and if I could device a way to join them back together I might end up with a spar that could be stronger than the original, just like a bone that has fractured and the body repairs it with extra tissue around the breakage point.

Whenever the slowly degrading weather allows for it that’s descending heavily down on us on our slippery slide towards the austral winter, you can find me at Ted’s shop tucked into the hillside behind Ashby’s Boat Yard, which has recently been incorporated into Northland Holdings, the secretive but opulent state owned entity that is managing and diligently milking the lucrative Opua Marina. Engulfed in a cloud of fine sawdust I’m fabricating wooden plugs that will slide into the bamboo culms for the entire length of the internodes adjacent to the ones that broke. It’s a tricky process. The bamboo has been brought forth by Mother Nature’s creative evolutionary magic, which means there are no perfect circles and no straight lines. Touch, feel and go it is then, shaving off the wooden material little by little until there is just enough left of it for the plugs to easily slide into the openings, without them wiggling around in there too much. Epoxy filled with glue mix will take up any empty space and make for a perfect bond between the two different plant materials. And of course on the outside a couple layers of reinforcing fiberglass will provide for the ultimate strength of this makeshift repair. A bridle will further help to distribute the considerable load and bending moment that acts on the halyard attachment when the wind increases and generates more and more pressure on the sail.

It will be as always with man’s technical things. A good leap of faith is needed to venture with these marginally constructed machines out into the chaotic world of the wavy oceans, which can brutally tear to shreds any and all human inventions if it happens to find it pleasing to do so. At the very least we will not only have saved our cruising kitty from prematurely collapsing into a very private but intimate replay of the Great Depression, but also be able to sweetly sleep with the clean conscious of having complied with the ecological mandate of reusing elements and resources whenever and as much as possible, instead of contributing to the menacing existence of an aluminum smelter maybe somewhere on the black back of Iceland and become part of a collective responsibility for the accelerated melting of three glaciers under the bright orange midnight sun in the elevated latitudes of the North Atlantic.

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Tags: Bamboo, crab claw sail, spars