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Pont Aven sub-propellers lead Brittany Ferries’ sustainability charge in 2019

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Pont Aven sub-propellers lead Brittany Ferries’ sustainability charge in 2019

Brittany Ferries’ Pont-Aven is saving energy and reducing fuel consumption thanks to the installation of two innovative devices on her propellers.

Wärtsilä‘s EnergoProfin system is a small sub-prop, which is attached to the main propeller helmet, helping improve propulsion in water. Two of these devices were installed during the ship’s dry dock in December 2018. As a consequence fuel consumption and emissions have been cut by around 2% on every crossing.

This project is a small – but significant – step and it comes as part of a range of studies initiated through Brittany Ferries’ Research and Development program. But, as Vincent Coquen, Head of R&D, Energy and Environment for the company, explains, it is not just a question of developing practical and technical solutions for today such as the propellers on Pont-Aven.

“Sustainable development means looking to the future and studying innovative projects and technologies that could be used in either the short or longer term,” he said.

For the past two years, Brittany Ferries has partnered with CEA Tech in France. Several projects are underway, including the development of a long-range broadband link that would use land-based transmitters to obviate the use of satellite-at-sea. A second study focuses on hybrid energy solutions for Cap Finistère, Brittany Ferries cruise-ferry that sails from the UK to Spain. The last is exploring the long-term implementation of fuel cells for powering certain of her on-board systems.

Brittany Ferries is also looking at the potential for wind energy. Flettner rotors, traction wings, or modern sails are at different stages of development, but could significantly reduce ship fuel consumption and therefore emissions.

“Of course, we must be cautious, checking the feasibility of integrating these technologies on board our ships, in terms of safety, reliability and profitability,” added Vincent Coquen. “But I am convinced that they will have a significant role in the equation that ship-owners must solve to achieve the zero emissions ship.”

 

 

Pont-Aven-Santander-AT-Wärtsilä-EnergoProfin-arrow.jpg

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3 hours ago, TonyMWeaver said:

Brittany Ferries is also looking at the potential for wind energy. Flettner rotors

Crickey, My son demonstrated a Flettner rotor during his Craft, Design and Tech course at school 30 years ago. His small boat moved along by Mums hairdryer. All in the bath!

Tell BF that it works, go for it.

Stu

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I am not sure how this has slipped past without more "hoa-ha".... In my eyes that is amazingly significant!

Simply stick a tiny little prop on top of the big one, and you save 2% across the board? Surely they will want to get that on every vessel as soon as possible?!

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Reminds me of the 'Grim Wheels' that were attached to the props of the old QE2 back in 1987 for the same purpose. They fell off...

Edited by cvabishop
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44 minutes ago, hf_uk said:

I am not sure how this has slipped past without more "hoa-ha".... In my eyes that is amazingly significant!

Simply stick a tiny little prop on top of the big one, and you save 2% across the board? Surely they will want to get that on every vessel as soon as possible?!

It about reducing energy loss.  Blade rotation produces low pressure which creates holes in the water, these then fill with air slowing propulsion. The smaller addition reduces these holes which in turn maintains more of the energy produced by the main prop.

There should also be a reduction in the damaging vibration which in time is destructive, it's caused as these air pockets/bubbles explode against the different metals... a reduction in cavitation.

Now we know why PA sailed to Astilleros, Wartsila make them in Santander.

Flettner rotors are what Viking fitted to Grace and will also be on her Chinese built sister and work in tandem with her LNG plant.

If BF are looking into hybrid systems as a way to power Cap Finistere in the future the oft' circulated rumours of her impending sale after the new builds arrive seem a bit off the mark? 

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9 minutes ago, cvabishop said:

Reminds me of the 'Grim Wheels' that were attached to the props of the old QE2 back in 1987 for the same purpose. They fell off...

Ah Otto Grim, the German Navy during WWII would have been nothing without him. I remember when Vladimir Shigunov was a researcher in Strathclyde Uni' about 15 years ago, I was up there when my missus was doing her MD. He's now at DNV looking at reworking Grim's propeller.

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Anything that reduces cavitation has got to be beneficial. Better "ride" better fuel efficiency and less wear on props.

Win win, as they say.

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14 hours ago, jonno said:

 

If BF are looking into hybrid systems as a way to power Cap Finistere in the future the oft' circulated rumours of her impending sale after the new builds arrive seem a bit off the mark? 

Jean Marc Roue has stated in previous interviews that he saw Cap Finistere posibbly going to the Ireland/Spain route , obviously I’m aware of the size restrictions as I’m sure he is.

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3 hours ago, kenw said:

Anything that reduces cavitation has got to be beneficial. Better "ride" better fuel efficiency and less wear on props.

Win win, as they say.

I wonder if ARM will get these too. Would be interesting to compare the before and after. I often thought that the vibrations at her stern when maneuvering can be awful - if you stand outside to watch the arrival of a morning holding the handrail, your arm nearly gets ripped out of its socket! Having said that, these won't affect the bow/stern thrusters so probably no different.

On ships like ARM, I wonder if it is worse / more noticeable because there is less superstructure at the stern (ie. less 'stuff' to absorb the vibrations), compared to Bretagne, PA for example...

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36 minutes ago, hf_uk said:

Having said that, these won't affect the bow/stern thrusters so probably no different.

Bow and stern thruster tunnels have armoured casings, are fitted with a type of shock absorbing and the blades are now formed using a slightly different metal composition.

It's very interesting stuff, there's a lot of work going on to see about harnessing bow thruster cavitation energy. It's about reducing oxidation and trying to make the process electrolytic by using cathodes and higher concentrations of zinc & copper. A salt bridge isn't required as it's already present in the salinity of the water.

A single cathode measuring 5x7cm similar to what is used in non invasive brain stimulation has an Eo of .76v so ok you'd need to build a large array within the tunnel for little return however again it's more about damage limitation by reducing oxidation which in turn lessens cost heavy maintenance and environmental impact ( can you imagine what effect these explosive bubbles are having on sealife?).

The shipping companies are under immense pressure from two directions, they must lessen the amount of wasted energy and their carbon footprint and reduce the impact of every vessel they have has on the environment.

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I have a question.... 
 

If you look at the picture of Honfleur here:  https://www.destinationhonfleur.com/en/news/merry-christmas-and-happy-new-year-flensburg 

That looks to me like it is not possible to fit a "mini prop"? Maybe Jonno will know. Surely they were aware of it when she was designed? Or does what is pictured mean that with the rudder 'behind' as it were,and that bulbous bit, there won't be as many of those disruptive bubbles described in this thread?

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That is a different type of energy saving propeller-rudder combination, I can't remember off hand the official name. A lot of companies seem to  all have their own efficient rudders. I would think it is a type that is more easy to fit during build, compared to the Sub-Props, which look to be more easily fitted. I would think the combination would improve flow efficiency.

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2 hours ago, hf_uk said:

I have a question.... 
 

If you look at the picture of Honfleur here:  https://www.destinationhonfleur.com/en/news/merry-christmas-and-happy-new-year-flensburg 

That looks to me like it is not possible to fit a "mini prop"? Maybe Jonno will know. Surely they were aware of it when she was designed? Or does what is pictured mean that with the rudder 'behind' as it were,and that bulbous bit, there won't be as many of those disruptive bubbles described in this thread?

These blades are highly skewed to reduce the vibration on the hull, the bubbles, meaning less energy is lost and increased efficiency on fixed pitched propellers

It can easily be seen in the image of PA's propeller that her blades are flatter, they're variable pitch meaning that the shaft only rotates in one direction regardless of whether she's travelling ahead or astern, the blade angle determines direction which in turn increases the bubble disruption when altered on a shaft still doing 500 -750 rpm. It means she's highly manoeuvrable but the downside is that she's less efficient when at sea hence the Wartsila addition which, in theory, should give her similar characteristics to the highly skewed blade.

 

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