SeSH-Oct19-Cover hi res.qxp_Cover 07.qxdahorse 23/08/2019 10:38 Page 2

Issue 476 £5.50 US$8.50

Game changer – Richard Jenkins The 12 Metre manual – Rod Davis Not for everyone – Andy Claughton Quite the journey – Vince Brun Now for the TJV – Sam Davies Iolaire no more – Don Street

OCTOBER 2019 ISSN 0143-246X On a wing and The official very little else magazine of the 10 Royal Ocean Racing Club 9770143246139 AH-SH-Oct 19 - Eagle TB_subbed.qxp_SH-March10 Table Final 22/08/2019 10:01 Page 1

Beam me up (Scotty)

Much-awaited by her enthusiastic following of fans of the smartest high performance sailing ideas the Eagle 53 is about to get airborne...

Tommy Gonzalez and his team at Fast sailing/flying an Eagle Class yacht Top: it’s wise Forward Composites have gone slowly because of this development of to skim and carefully with their Eagle Class 53 autonomous foiling controls. before you try project, recognising that previous l and wing development: the to fly. The Eagle Class attempts by others to leap towards first 3Di sail produced by North to fit 53 is still a the promise of foiling large multihulls to the back side of the solid wing had fledgling, with have had unsuccessful and even a 12 percent chord depth, and the its creators very sensibly

RACHEL FALLON-LANGDON dangerous outcomes. As he says, it team is now reduced that to only nine took years of efforts at the ’s percent as the efficiency and speed focused on Cup to apply the focus on research, increases and drag decreases. skimming rather than design and testing to start to get it Tommy and Randy want to see this fully flying on right at that level, and without those reduced even further to only 6% to its foils. Even resources then understanding the minimize the curvature in the wing, so, this nuances of control in this design reduce drag, and thereby pointing cutting-edge space dictates a more measured and higher allow even more speed. yacht has methodical approach strategy to Testing in St Barths showed upwind already achieved understand foiled flight to get it right. speeds of 15-19 knots are possible. remarkable So it’s exciting to see that after a l While the foils have been designed upwind winter of testing and refinement in to articulate as much as 12°, in speeds of 15 the Caribbean and now a summer testing with C-foils they have been to 19kts and of testing close to the shop in Bristol, limited to only 4° to allow for better sustained the Eagle Class 53 has made great understanding of their effects on downwind speeds of progress in its quest to be ready for performance. Gonzalez says they are 28kts during harnessed and controlled flight. perfecting the technique of recent sea Gonzalez and his team have been “skimming” the Eagle with the current trials in the tropical sun, and the strength of the using a Stilleto 23 cat as a scale C foil configuration. This mode keeps Caribbean, material in these conditions was only model to test ideas before trying them the windward hull just kissing each which good for four months, so new Oratex on the Eagle Class 53, and can report wave while the leeward hull is lightly included a fabric is being fitted. 200-mile l progress in the following areas: skimming the surface for a fast and offshore A smaller ball and cup at the base l Machine learning: to completely controllable mode. passage in of the wing was devised to spread understand and be efficient with the l Substantial work has been done a big breeze load over a greater area. This has control of the T-foil surfaces on the on the wing bearings. The original that proved reduced rotation friction. rudders and centre boards, there design’s outer and inner races of the boat’s ‘The winter season taught us a has to be a process of handling the titanium bearings in aluminum strength and lot,” Gonzalez says. “The 200 miles seaworthiness. immense amount of data coming saddles proved problematic at tight Right: the of sailing in big breeze and waves from the control surfaces. The field of tolerances due to the differential T-foil rudders from St. John to St. Barths and back machine learning provides guidance thermal expansion characteristics and their taught us the boat is structurally on letting a computer learn through of the two metals. With this in mind, attachment to sound and can take a beating. Big the testing process where the ideal the saddles have been redesigned the hulls need waves can break over the boat, but settings should be to achieve optimal to have an outer race only. to be very exit straight out the back. At times we strong indeed l performance. This is an innovative Clysar shrink films have been used to withstand had 12 to 14 people on board, which and clever method to semi-automate on the wings to allow for inspection the extreme is significant weight for this boat, and the testing process towards the of the framework structures for any loads they are we noticed only small effects on eventual goal of having automated evidence of damage, breakage or routinely performance, and none on settings for the foiling surfaces based cracking, and none have been found. subjected to seaworthiness or safety. With as on parameters of wind speed, wind However, it was found that the when sailing many as eight on board we could fully at high speed angle, sea state and the desired weather in the Caribbean elevated particularly skim. Our top speeds in these tests course steered. Eventually trial and the temperatures within the wing to in waves reached 28kts sustained.’ error will not be necessary in very high levels while in the sub- www.fastforwardcomposites.com q SEAHORSE 65