SPORT - Eagle tows 114 Horsehead skiers
Members from Devonport’s Horsehead Water Ski Club assembled at Strahan on March 28 and set a new waterski world record for the most number of skiers towed by one boat. The Tasmanian 36m Incat Crowther tourist cat Eagle broke the previous 100-skier mark with 114 skiers behind her, at the club’s eighth attempt.
The club had already set the mark for pulling 120 skiers from a deep start in January this year (the most ever behind one boat), but with “only” 99 making it through the required nautical mile it was two skiers short of a record.
For the successful attempt in March, the club managed to get 116 skiers started and still had 114 up at the conclusion, smashing the 100-skier mark established by the Cairns & District Powerboat and Ski Club on Trinity Inlet in 1986, coincidentally behind another Incat Crowther designed vessel.
Eagle, which operates from Strahan, was fitted with a custom-fabricated boom across its stern to spread the large number of skiers out. Incat Crowther said it provided structural design support for the boom and detailed drawings for the manufacturing of all components and attachment points.
Incat Crowther naval architect Kristian Fet spearheaded the support effort of the Sydney-based design office.
“The club came to us with technical questions, and we welcomed the opportunity to get involved in a world record,” said Fet. “As well as designing a boom that would be strong enough, we had to come up with a way of attaching the boom that minimised the need for any modifications to the vessel.”
The Horsehead club had previously attempted to set the record using Eagle but was restricted to using boom designs not rigidly attached to the then brand-new boat. This raised a number of issues and all the three previous attempts on breaking the record were halted by boom or rope failures.
Following these first unsuccessful attempts, the committee finally obtained permission from the operators of Eagle to attach a more substantial boom to the vessel.
The organisers then turned to Incat Crowther for design help. Fet was handed a conceptual design and through extensive finite element analysis was able to simplify the original concept into a boom that was both easy to construct and assembled in a short amount of time. A nonlinear static solver in combination with cable elements for the support ropes enabled an accurate prediction of the boom’s behaviour as it is gradually loaded up with the drag from 120-plus skiers.
“The use of stepped-load increments allowed us to view the transition between only gravity acting on the boom setup and the full design loads applied,” said Fet. “Having satisfied ourselves that all forces and stresses observed had comfortable safety factors on failure, attention was then turned to the finer details of attaching the boom system to the boat.”
Incat Crowther said the attachment is so simple, the ski team was able to do the record run at 7.30am and remove the boom setup in time for the ferry’s regular tourist run at 9am.
Disassembled, the complete boom and mast fits comfortably on the back of a small truck.
The Horsehead club’s achievement continues a long association between Incat Crowther and the world record. The record of 100 skiers set by the Cairns club used an Incat Crowther designed vessel. In 2000, an attempt was made in San Francisco Bay using an Incat Crowther boat when the company’s affiliated yard, Nichols Brothers, provided the 40m Klondike Express.
“We don’t actively put ourselves out there as being skiboat designers”, says Incat Crowther managing director Brett Crowther, “but it is an extreme example of the versatility of our craft.”
Incat Crowther said plans are being made to attempt to stretch the record even further, with some members of the committee believing they can achieve as many as 150 skiers. Incat Crowther said it believes the Eagle is capable of the job and stands ready to assist future attempts and help the club extend the record.
Incat Crowther congratulated the Horsehead Water Ski Club on its achievement and extended an offer to continue supporting them in their future attempts.
“It isn’t going to be a one-horse race, however, with at least two other clubs announcing attempts on the record. With over 300 vessels in operation, there’s every suggestion that Incat Crowther’s association with the World Water Ski Record will continue for many years to come,” Incat Crowther said.
Photo: The Incat Crowther designed cat Eagle tows 114 skiers to a world record (photo © Mark Seaton Photographics).