Etchells Class modifies illegal boats
Published on December 24th, 2022
When the Australian-built Pacesetter boats uncommonly dominated the 2019 Etchells World Championship, eyebrows were raised. After investigation confirmed discrepancies, the class sought a solution for the 25 boats built from the M11 mould. International Etchells Class Association (IECA) Chairman Andrew Cumming shares what happened:
In order to independently evaluate the differences between M11 boats and Etchells, an international panel of marine architecture experts led by Tom Schnackenberg (NZL) was assembled and empowered to study the shape differences between the boats and try to come up with some sort of modification to the M11 boats which would allow them to ultimately race level against Etchells.
In order to pursue the twin goals of a) modifying the existing M11 boats and b) creating a new mould (to be called M12) for the manufacture of class-rule-compliant Etchells sailboats in Australia, the Build Panel was struck consisting of the builders, independent expert Grant Simmer (AUS), several members of our One-Design Technical Committee (ODTC), with myself and International Etchells Class Association of Australia (IECAA) President Martin Hill (AUS) as observers.
Chaired by Schnackenberg, this independent panel was struck in 2021 upon the confirmation by fresh scans of multiple boats from each manufacturer being compared by Australian Measurer Shaun Ritson, the result being that M11 boats were found to be of a distinctly different shape than Etchells created from moulds which originated from Plug 2.
CFD analysis confirmed that the M11 shape produces less drag than the P2 shape, especially at speeds approaching the hull speed. After aborting a number of inadequate methods for equalizing the drag, the panel happened upon a brilliant solution (inspired in part by a suggestion offered by Jamie McWilliam). If the M11 boats have essentially the same sections as Etchells, but just a reduced rocker perhaps Etchells speed characteristics could be restored by simply adding back the rocker.
A digital version of the M11 boat was sliced from kelson to sheer (but leaving the deck intact) along station planes fore and aft of the keel. The virtual boat was then lifted in the bow and stern to put back rocker. Various degrees of lift were applied to the bow and stern and CFD analysis performed and compared to the Etchells shape.
In this way, the rocker was fine-tuned until the drag differences across a wide range of hull speeds were reduced to very nearly zero, and a final shape determined. Martin Hill graciously offered up his M11 boat (AUS 1484) for modification under the new protocol, which was written by Jamie McWilliam. (thanks to Tom Schnackenberg (NZL), Grant Simmer (AUS), Len Imas (USA), Steve Killing (CAN), Bruce Nelson (US), Shaun Ritson (AUS) and Casey Brown (US))
The Build Panel, Chaired by Niesje Hees (AUS), was put together as a joint initiative by the IECA and the IECAA to oversee the practicalities of modifying the M11 boats (as specified by the M11 Modification Panel), in addition to the construction of a new mould (M12) to be used going forward for the manufacture of Class-Rules-Compliant Etchells sailboats in Australia.
The vast majority of stakeholders believe that the strength of the class going forward as a global international heavyweight depends on having manufacturing capabilities in Australia, and it was considered one of the paramount goals of 2022 to get Plug 2 prepared for the pulling of a new mould, get it shipped to Australia for that purpose and get the creation of a new mould underway.
Unfortunately, this project faced a number of delays mostly due to shipping logistics from Canada to Australia, after the plug had been prepared by Ontario Yachts. Innovation Composites of Nowra, NSW will be the builder of the mould and ultimately be licensed to make Etchells from that mould, once it has been verified and approved by World Sailing.
IC is also doing the modifications to M11 boats, and so even once the plug got to AUS there were more delays in commencing to build the new mould, however, that project is now underway as I write this.
As for M11 modifications, eight boats have been modified and have been racing in events in Australia. There have been no structural issues with the modified boats and early indications are that they perform in line with Etchells Class sailboats. These boats have been and will continue to be allowed to race as agreed upon in the IGC Resolution.
The long-term status of these boats will be determined by a class vote in April 2024.
(Thanks to the following individuals for their continuing service on the Build Panel: Chair Niesje Hees (AUS), Grant Simmer (AUS), Jamie McWilliam (HK), Andrew Palfrey (UK), Bill Abbott (CAN), Phil Smidmore (AUS), Mark Rowed (AUS), Dirk Kneulman (CAN), and David Heritage (UK).