A new generation of propulsion for Ferretti yachts

Posted on August 11, 2022 by Lucie Maluck

Even combined with SCR for IMO-3 approval, the top performance of mtu Series 2000 units in Ferretti Group Custom Line yachts remains uncompromised.
Even combined with SCR for IMO-3 approval, the top performance of mtu Series 2000 units in Ferretti Group Custom Line yachts remains uncompromised.    

Anyone who believes that sustainability is something the yachting world will never be able to embrace should look to the harbour city of Ancona in the east of Italy. This is where, against the stunning backdrop of the Adriatic coast, yacht-builder Ferretti Group with its Custom Line brand puts its Custom Line 106 yachts through their paces before handing them over to customers. Today, a very special yacht in the series is due for trial – the first to be powered by mtu Series 2000 units with IMO-3 approval. The 16-cylinder engines are equipped with integrated Selective Catalytic Reduction which substantially reduces emissions.

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First yacht to have an mtu propulsion system with IMO-3 approval

The purchaser of this latest model can look forward to a vessel in a class of its own: sleek and athletic on the outside, chic on the inside, and furnished with pure luxury all the way along its 33 m length. In other words, a yachter's dream. Ten boats from the Custom-line-6 line have already been sold. But this eleventh yacht in the series is now the first with an mtu-IMO-3 propulsion system.  

Custom Line 106 is 33m long, about 7m wide and powered by twin mtu units propel them to a top speed up to 26 knots (48 kmh).

The mtu engines of the type 16V 2000 M97L not only bring the yacht to a top speed of 26 knots (about 48 kilometres per hour). Because they are equipped with integrated SCR, nitrogen oxide emissions are significantly reduced. So with a propulsion system carrying IMO-III certification, the yacht owner is authorized to enter emission-control areas (ECA zones) such as the coastal waters of Canada and the USA, as well as the Caribbean and the North and Baltic seas.  

As powerful as the previous engine version  

Today however, the yacht is being put to sail around Ancona, just 100 meters away from the shipyard in which she was built. But there are no sun-bathers on board – instead, engineers and measurement technicians from Ferretti Group Engineering Department and Rolls-Royce Power Systems, all in a state of suspense about how the yacht's new propulsion system will perform. “Of course, we're nervous,” admits Rüdiger Grau, who technically led the development and testing of the mtu propulsion system at the Rolls-Royce Power Systems headquarters in Friedrichshafen. There on the test stand, the mtu Series 2000 engines with IMO-3 approval performed just as well as the previous IMO-2 units that did not have SCR. But how will they fare out at sea, where conditions are not laboratory-controlled? Will the turbochargers be able to handle the high exhaust gas backpressure caused not only by SCR, but by the underwater exhausts typical of yachts, and also by the sea state?   Will the heat produced by the SCR system be properly conducted to outside the engine room? And how loud is the final propulsion system in the engine room - will it disturb the guests on board?  

The integrated SCR system considerably lowers the release of contaminants from the mtu engines
The yachts built so far in the custom line 106 series also have mtu Series 2000 engines in the engine room – but without an SCR system.

The test crew had plenty of test items on the agenda. One of them involved Custom Line Testing & Delivery Supervisor Captain accelerating and then braking the yacht abruptly. Another was a fast bend – a yacht maneuver often included in test protocols. While that was happening, the job of measurement technician Jan Leuthäußer from Rolls-Royce Power Systems was to watch engine behavior closely. But it didn't take long for relieved smiles to be seen all round when the Rolls-Royce test crew which consists of employees from Germany and Italy happily announced that “All was going to plan”.

“In today's trials, the mtu 16V 2000 M97 unit showed us that it's every bit as powerful as its predecessor. And with SCR, a lot more eco-friendly”.

Carsten Voigt - Project manager at Rolls-Royce Power Systems

Custom Line Testing & Delivery Supervisor Captain and his crew were particularly impressed by the outstanding acoustic properties of the propulsion system. With a strongly insulated engine room, engine noise and vibrations were hardly perceptible on deck. “It's so important for green engines to be able to offer our customers the carefree yachting experience they're used to,” explained the Captain. The yacht captain was also keen to emphasize Ferretti Group's strictly customer-centric approach – with top priority being given to customer satisfaction with on-board ergonomics and acoustic comfort as well as to design. “We're forever pushing the boundaries so that we can offer our customers an absolutely exceptional yacht experience,” said the Captain.  

Hybridized future

Hybrid propulsion will also be part of the future scenario, with Rolls-Royce currently developing a fully integrated mtu hybrid solution delivering 1,432 kW per power train. The IMO-3-compliant system shall comprise twin 12-cylinder mtu Series 2000 M97 diesel engines, electrical propulsion modules, gearbox, batteries, control and monitoring systems, further electronic components and an SCR system. These bring even greater power and comfort to the yacht.   In electric-only mode, yacht operation is quieter with low vibrations and emissions-free in harbor areas.  

“Hybridizing propulsion is one possibility for making yachts greener. We're currently working on modular solution architectures in which hybrid systems will be combined with future technologies such as methanol engines, fuel cells and batteries – all with the aim of making yachts greener and more comfortable at the same time.”

Tobias Kohl - Director Marine Engineering Applications at Rolls-Royce Power Systems

But back now to the Adriatic coast and today's tests. Custom Line Testing & Delivery Supervisor Captain patiently performs the next maneuver which Rüdiger Grau and the Rolls-Royce test crew are keen to carry out to establish how the engine reacts to abrupt braking. “Really well” is their unanimous opinion. The Captain is equally convinced: “These new mtu engines are indeed as powerful as their predecessors, even with the SCR system,” he says. He and his crew shall be handing the yacht over to the new owner and training his team. Briefly, this will be the only crew in the world using the new IMO-3-compliant mtu engines. But only briefly, because in the Westport and Delta Marine shipyards in the US and at Gulf Craft in Abu Dhabi, other yachts with IMO-3-approved mtu Series 2000 engines are being built.  

Which just goes to show that on yachts, sustainability and luxury can indeed exist in perfect harmony.