BOOSTED BY ROLLS-ROYCE’S AZIPULL CARBON PROPULSION SYSTEM, THE BENETTI FAST 125’ IS A 38m FOUR-DECK SUPERYACHT BOASTING SPEED, AGILITY AND EFFICIENCY.
LAUNCHED THIS YEAR, the four-deck Fast 125’ marked the start of a new partnership between Benetti and Rolls-Royce, which designed and built the yacht’s new-generation Azipull Carbon 65 propulsion system.
We had already tried out the first hull of this series (Ironman) and were struck by the performance it delivered for a yacht of its weight, volumes and, most importantly, very high standard of comfort.
Benetti has made further non-structural modifications to the third hull in the series, Skyler, that are still significant in that they further reduce noise and vibration. (The fourth hull, Lejos 3, has also been launched; hulls five and six are in build.)
Some small but significant changes in Skyler have boosted comfort levels at all speeds, including those when vibration from the engines, transmissions and exhausts tends to be most invasive.
In this version, for an American owner, the wave-piercing bow has also been slightly modified and is slightly fuller than the previous hulls, which further boosts aerodynamic efficiency. There was also a focus on weight containment as the yard spent great time and effort on the selection of the materials used for the hull and superstructure construction.
Benetti used composites with GRP for the hull and carbon-fibre for the superstructure. This meant that the superstructure was lighter, which is significant as this will make the most impact on trim.
The upper deck has a fantastic foredeck and interior sky lounge.
The aft area of the upper deck is ideal for socialising and dining.
Naturally enough, the yard’s goal was to deliver a high standard of onboard living and so a focus on reducing noise and vibration was a central consideration in the design process. There’s no mechanical coupling between hull and deck, which instead are actually ‘glued’ together, so noise and vibration generated elsewhere tend to be absorbed.
This also holds true for the main-deck flooring, which was designed to absorb noise and vibration from any of the submerged mechanics or appendages.
Like all Fast 125’ models, Skyler uses Azimut Benetti’s revolutionary D2P (Displacement to Planing) hull form that allows the owner to use the yacht in displacement mode at low speeds with low fuel consumption, and in planing mode at higher speeds.
Andrea Moschese, Project Manager for Benetti’s Fast series, said: “The Fast 125’ is a genuinely innovative design that stretches 38m in length and 8.45m in the beam, so the volumes are very good as they also benefit from the aft position of the engines and drives.
“Construction wise, we introduced a whole slew of new features from the hull’s unusual displacement-to-planing form, which is hydrodynamically efficient in both planing and displacement modes, to the extraordinary propulsion system that Rolls-Royce developed for us.
“All this means we can make 12 knots and still enjoy the particularly high comfort and low fuel consumption of a pure displacement yacht. But due to the Azipull Carbons and their characteristics, we can push on up to 22 knots without losing any of the comfort or extreme manoeuvrability.”
Moschese said the ‘extreme manoeuvrability’ was a huge bonus for a superyacht, while the propulsion system’s location aft meant a tender garage could act as a buffer between the accommodation, further reducing vibration and noise for guests.
“This propulsion means we can offer yachts that are very easy to control and can execute the kind of manoeuvres in port and during navigation that you could usually only manage with a 40-footer rather than an almost-40m yacht,” he said.
“That said, the efficiency they can deliver integrates seamlessly with the hull lines. This system also allowed us to optimise the way we used the stern volumes because of the direction coupling of the engines and the Azipods. The result is more space for owner and guests.”
These words would echo in our analysis of the third Fast 125’. Even as we spoke with him, we were pulling out of the port of Viareggio – but only realised that when we looked out of the window. This ultra-smooth ride was due in large to the propulsion system.
The spectacular sun deck has several socialising and sunbathing areas.
Proud partnership with Rolls-Royce
Rolls-Royce’s Azipull is a high-performance, low-drag, lightweight pulling azimuth thruster that uses carbon-fibre throughout, even for load-carrying parts. The steerable Azipull combines the advantage of a pulling propeller with the flexibility of using almost any type of drive.
Manoeuvrability, hydrodynamic efficiency, fuel efficiency, course stability, low noise and vibration levels are key characteristics. Each thruster weighs 2,800kg, with the inboard part weighing about 1,150kg. The underwater part including propeller amounts to about 1,650kg, although when the vessel is afloat the ‘effective weight’ is about 660kg due to the buoyancy in seawater.
Italy-based Andrea Cerutti, Rolls-Royce Marine’s General Manager of Sales for South Europe, explained how the company developed the new propulsion system for the Fast 125’, having collaborated with Benetti for several years.
“It’s important to know where this technology comes from. It was derived from the initial Azipull project, an all-steel thruster that delivers 1,000-5,000kW that we launched back in 2004 and have since installed on numerous commercial vessels including ferries, cruise ships and freight ships.
“Carbon-fibre became a necessity because we realised it would allow us cut the 1,600kW Azipull 85’s weight from 14 tonnes to just two tonnes for the Azipull Carbon 65, which unleashes 2,000kW. We managed to boost input power while reducing torque and weight by using a smaller screw.”
This major development meant Rolls-Royce could now look at solutions for displacement and planing boats, as Cerutti explained.
“We went with Benetti because they developed a programme very much in line with Rolls-Royce’s desire to tackle a genuinely difficult technological challenge,” he said.
“You can easily see the huge performance advantage for yourselves. We’re on a yacht of nearly 40m, but we have no vibration or noise from either engines or thrusters. Also, our fuel consumption is definitely below average and we can reach speeds of over 22 knots.”
The main deck saloon, dining area and walkaround side decks.
RWD offers three interior options
The Fast 125’s interiors are designed by British studio RWD (Redman Whiteley Dixon). Skyler is a custom version adapted from the modern, minimal Air option, one of three versions offered along with Sea, for marine tones, and Land, for a warmer atmosphere.
Many of the woods, such as ebony and herringbone anigre, and other materials were sourced directly in the US, where a lot of the detailing was done at the owner’s request. However, many other materials are Italian.
The master suite is on the main deck and takes up the entire width of the structure. There are also two side balconies which provide natural light and a nice through breeze.
Guest accommodation on the lower deck comprises two large double suites midship and two twin cabins, all with their own large en-suite bathrooms.
The fact that the engines were pulled back towards the stern opened up more space for the interiors. In this case, the yard chose to put a big garage between the engine room and the guest accommodation.
The garage has a side hatch and is large enough to hold a 5m-plus RIB plus two jet skis. That meant a large beach platform could be created aft, an area that has direct contact with the sea and offers cleverly designed onboard toys.
The master suite has a pop-out balcony on either side.
Efficient on many levels
Fuel consumption is low, at around 408 l/h, until the yacht hits its cruising speed which is around 15 knots. If the throttles are eased back a little to a speed of 12.5 knots, fuel consumption drops sharply to 208 l/h.
The maximum cruising speed – the pace you might make over a long passage without putting the engines under undue strain – is 16.3 knots, which is definitely very brisk for a yacht just under 40m. At 10 knots, overall fuel consumption is around 100 l/h, which translates into a very impressive range.
On the right is a summary of the main data to emerge from our sea trial, which was carried out in a calm sea just off the port of Viareggio – where the yacht was launched – with about 50 per cent of fuel and water, and around 30 people aboard.
Our impressions were as follows: consistently excellent manoeuvrability at all speeds, noise and vibration levels that are clearly the fruit of some very advanced technical research and targeted solutions, very good performance figures for such a spacious comfortable 38m yacht, and attractive fuelconsumption levels.
All these factors combine to make the Fast 125’ a genuinely multi-talented yacht, as ideal for long-range cruising as for fast passage-making, offering the same superb comfort, security and uncompromising quality regardless. http://benettiyachts.it
Anticlockwise from top right: Stairs to the lower deck; beautiful bathroom; a guest double; gym.
The large swim platform offers direct access to the sea.