In last month’s update with our own deadlines for posting the latest diary entry, we just missed being able to report to you on how our good friend Dave Warby and his team had gone on with their latest round of testing. This was done over the last weekend of March at Taree, New South Wales, relatively local to them with their jet hydroplane Spirit of Australia II. As regards the weather they had some rain on the Saturday with strong winds that night but reasonably fine when it needed to be if still a little choppy out on the river. We hope you enjoy the following short video of their boat in action over that weekend:
Despite trying different water immersed rudders there remained a tendency for the boat to pull to one side as it ran along the course. Tracking the issue down appears to suggest that the vertical aero fin over the rear of the jet pipe was slightly out of alignment. Dave said it was easier to make a new fin altogether than to try and amend the existing one and the following photos show the new fin being formed by him:
Just to show how life can throw you a curved ball when you least expect it, in mid April a stolen car crashed into the front of the building where Dave’s jet hydroplane Spirit of Australia II was being stored and then the car burst into flames. With that fire raging on the other side of the workshop door they could have lost the boat, its engines and all their support equipment that he and his team have spent the last few years building but fortunately the local fire brigade and emergency services were on the scene very quickly to get the situation under control and save the day:
Dave and his team are currently running around getting everything sorted for their much longer trip of going to Blowering Dam during mid May for their next round of tests. When Dave’s father Ken managed to become the fastest person on water in the world, back in 1978, one of the chaps on his team who helped Ken an awful lot with developing his boat was Bob Apathy and it is great to see his son Rodney now helping Dave during testing for his attempt on the Outright World Water Speed Record.
We hope the weather is kind to them during their stay at Blowering and the new vertical aero fin Dave has made and fitted this month resolves the tracking issue. We will report how they get on at Blowering in a future diary update and in the meantime wish them all the best with this next round of tests.
Back here with our build of Longbow, the next job on the to do list was to form the bow to the craft from a block of Sitka Spruce kindly supplied by Robbins Timber and here you can see us teasing it from a rectangular block into the required profile:
We also moved on to fitting the battens to the underside of the hull, remembering from our previous updates that the hull shown in these photos is upside down to allow access for such work. The battens run parallel with the central keel from the transom all the way to the front of Longbow. They are attached to the timber frames below them by a combination of screws of marine grade supplied by our product sponsors Avon Stainless Fasteners, combined with the West System supplied by Wessex Resins as an epoxy bond:
Once the battens were in place Steve formed the small timber support blocks to go each side of most of these battens:
Followed by Fred setting them in place:
These blocks apparently act to increase the bond shear area and provide a mechanical stop. This reduces high stress concentrations in this detail, according to our design engineer Paul Martin and they just finished the job off nicely.
Taking our time and with a little patience everything began to come together in relation to the underside of the hull and we also started to form the housing joints that will accommodate the mid rails on the sides of the hull. As we stood back to look at the hull as a whole we could now start to appreciate Longbow’s elegant and purposeful shape which we hope you like too:
That is all for now folks and we hope you enjoyed this little update keeping up with our venture and that of our good friend Dave Warby. If you are not too busy then please tune in next month to see the next stage of the build of our jet hydroplane Longbow and associated things that we have been up to, as it all nicely starts to come together.