Subak2 Construction Notes
The Subak2 was constructed from an abandoned plywood racing dinghy. The usable area was extended with old and new water pipes, which were bound together with a wooden frame from sustainably harvested New Zealand pine and the old boom. The rear area was then decked with old shipping palettes. An A-frame mast was built using the same sustainable pine. We hung the mast in this from as the yard of a lateen or dhow-rigged boat. The sail was made from an old advertising banner for a soft drink.
The construction was designed in such a way that the entire vessel on its trailer could take part in the Adelaide Fringe Festival parade as part of the RI Australia group. We had a maximum allowed height due to power cables. This led to a lower sail and mast than would normally be used in a dhow rig.
The rudder and centreboard were from the old dinghy, with the rudder surface extended by wiring on a piece of marine ply taken from a rubbish bin in the Yacht Club. The yuloh was shaped from a discarded roofing beam with a meter-length of fallen gum tree branch as its handle. The oars were built from two planks of sustainable pine with handles carved into them.
We made no great calculations for the construction, other than height, as the entire planning and construction occurred within two weeks. We estimated weight and the depth of the vessel via displacement and knew that we had enough pipes. If they did not leak.
Sailing the basic dinghy with the sail but without the pipes, we were able to tack at 50-60 degrees to the wind. This was surprisingly good. This proved to be impossible with the pipes. On the river we found that the wind was channeled to be either on the bow or astern. With the wind astern, the sail was so far out to one side that controlling the vessel was difficult as the wind was steering us to the other side. We found that by raising the centreboard partially we could get some control and steer with one person on the rudder and another on the centreboard. However we still had to tack downwind.
The continual refinement of the yuloh and its post, reinforced with wood and nails taken from a motor palette donated by some mechanics repairing a houseboat, led to a state near the end when the yuloh was more efficient that the oars, as well as being more comfortable. On the penultimate day we had our maximal speed of 7.2 km/h with a storm behind us. As we turned the corner we battled against the same wind and found that only a combination of yuloh and oars could keep us just moving forward.