Executive in Action: Brunello Acampora - Founder, Flexitab and Victory Design
Is the K-Drive the "key" to more efficient propulsion?
![](img/no-image.jpg)
“This is a long-term project. It requires a cultural change and shipping is a highly conservative industry,” says Brunello Acampora, naval architect and founder of Flexitab and Victory Design. Acampora is describing the culmination of a passion that started at age 10, and he is working on it now with his hero from that time, Renato “Sonny” Levi.
Brunello and Sonny have developed a propulsion system called the K-Drive that uses a partially submerged propeller and which tank tests have shown can improve efficiency by over 10 percent for a standard hull-form container ship.
Learning the Ropes
At age 10, Brunello’s father bought a Drago – a futuristic high-speed powerboat designed by Sonny, which was propelled by custom surface drives. “I was born in a family with a strong passion for the sea and stimulated by creativeness,” he explains. “My parents were involved with the high-fashion biz, and a lot of famous Italian fashion designers were always around, but Sonny became my hero. I wanted to design boats. I was about 14 when I managed to get hold of a book written by Sonny, Dhows to Deltas, and albeit my English was very poor, I managed to read it all, over and over again. When I was 18, I managed to get a meeting with him at the Genoa Boat Show.”
A year later Brunello started studying as a yacht and powercraft designer at Southampton Solent University in the UK. “I used to go to Sonny’s house on the Isle of Wight to bother the master with questions and seek advice on many issues. Talking to him during those years was a delightful learning experience as it still is nowadays.” Back then, Sonny was designing Richard Branson’s successful, record-breaking monohull Virgin Atlantic II, obviously with custom surface drives.
After experience as a junior designer at Cougar Marine’s drawing office (UK), Brunello moved to Turin in Italy to found Victory Design, the naval architecture and marine engineering firm that he still owns and manages today. “My very first design was commissioned by the Australian hairdresser tycoon Stefan. It was an aluminum racing catamaran built by Lloyd’s Ships Australia over 20 years ago, and it set many records, including the fastest Sydney-to-Brisbane transit.”
With Victory Design he has since designed many successful race boats including the winner of the Cowes -Torquay race in 1993, a record still unbroken. All the designs had surface propulsion.
From Racing Boats to Merchant Shipping
About twelve years ago Brunello started a new company, Flexitab, dealing with the design and production of innovative propulsion and control equipment. “It was very clear to me that partially submerged propellers were not just suited to high-speed crafts since I knew that, adopting proper design parameters, even very
slow-planing crafts could benefit from larger diameter propellers and no appendage drag. The point was that the “experts” were always very reluctant to accept this concept – and many still are today – basically because they do not know how to make the thing work. It’s not in the books, you see.”
Brunello decided to enter the merchant shipping world with the aim of proving to everybody that this technology, properly designed, is the most efficient way of propelling any surface marine vehicle, regardless of its design speed. “Everybody laughed at me, saying that it would never work and that it was insane in its own principle, but when I talked it to Sonny he just said, ‘I cannot see why it shouldn’t work.’” So Flexitab and Sonny joined forces and began to develop K-Drive.
The K-Drive propeller blades are large-diameter and unconventional in shape, and the distance between the propeller and the transom is reduced compared to other surface-piercing propeller systems. Brunello continues to develop the computational fluid dynamics models needed to expand on the initial tank tests, and he and Sonny are expanding their patents worldwide while looking for a partner to implement the technology on a full-scale vessel. They anticipate that the K-Drive system will be well suited to large and medium-sized container vessels, RoRo passenger ferries (with transom ramp modifications) and cruise ships.
The “K” in K-Drive indicates that it is the “key” to faster, cleaner, cheaper ships. “Independent reports from respected tank-testing facilities, run by the universities of Genoa and Naples, confirm this to be true,” he concludes. The K-Drive is a sound principle, and it shall eventually convince even the sceptical experts.” – MarEx
The opinions expressed herein are the author's and not necessarily those of The Maritime Executive.