Nelo sculling boats

[thomas....@googlemail.com]

It’s been interesting to see Pedro Fraga racing in a new NELO racing shell at both the Turin Silver Skiffs and this weekend’s Scullers Head, mostly because of its unique bow design, you can see it in the photo below and also the mention of the patent on their site

http://benrodford.photoshelter.com/gallery-image/Crews-51-100/G0000pbcabSzfld0/I0000cjYdOtiePFw/C0000o5IlO5d8c_k

http://www.nelo.eu/news/article/nelo_patents_revolutionary_design

I understand that NELO are one of the biggest manufacturers of Kayaks currently, certainly their site mentions they won more medals than other manufacturers at Rio, and I believe that they previously used to manufacture the Stelph singles before the work was shifted to the far east so they obviously have experience in manufacturing single sculls and it’s interesting to see them apply the tech they have developed for Kayaking into sculling – certainly working with Pedro Fraga is doing them no harm as he placed second overall in Turin and first overall at the Scullers Head so hes obviously comfortable in the boat

[Brian Chapman]

They brought one to the World Masters in Copenhagen. An interesting design, but I would want to try one before buying. They are not far from Porto so a trip from the UK would be quite easy, with some Port tasting to fill out a weekend.

[Henry Law]

On 29/11/16 16:53, thomas....@googlemail.com wrote:
> It’s been interesting to see Pedro Fraga racing in a new NELO
> racing shell at both the Turin Silver Skiffs and this weekend’s
> Scullers Head, mostly because of its unique bow design, you can
> see it in the photo below and also the mention of the patent on
> their site

It's a little hard to see in the photograph, but the bow of that single
doesn't look altogether like the kayak bow in the patent picture; is
that just the angle?

What does this bow design do? Presumably, "make the boat go faster"
(TM). But how? I know nothing about boat design so I'm well prepared
to be proved wrong here, but an "inverted bow" seems intuitively wrong
to me, in that it would cut into the water rather than rise above it.
More to the point it's different from pretty much everything else that's
been done, and human beans have been making ships for a goodish while
now, right up to Resolute, with their background in racing yacht design
and so forth.

So some earnest of quality other than "it's patented" would seem necessary.

--

Henry Law Manchester, England

[thomas....@googlemail.com]

From the look at it I had in Turin I would say the single now looks similar to how it is shown in the linked paper, like you I was curious about the buoyancy in the bows but actually bar the reverse tapering a over the water it "seemed" like it has a similar surface area under the water - it was certainly a very solid boat, like my experience with one of the original Stelph boats that I part owned

[Valgozi]

On Tuesday, November 29, 2016 at 11:22:52 PM UTC, thomas....@googlemail.com wrote:
> From the look at it I had in Turin I would say the single now looks similar to how it is shown in the linked paper, like you I was curious about the buoyancy in the bows but actually bar the reverse tapering a over the water it "seemed" like it has a similar surface area under the water - it was certainly a very solid boat, like my experience with one of the original Stelph boats that I part owned

I have been looking for more info on these boats since a tweet about them from @AdamFreemanPask https://twitter.com/adamfreemanpask/status/774238864332431361

I don't understand why there isn't anything on Nelo's website or Facebook. Is it a custom made boat for Pedro Fraga or are they in the early stages of production so might be a while yet before they start selling to the public? Fraga is an international lightweight so is his finishing position in either of the races no surprise or is he performing better in the new boat?

It appears that as well as being the biggest kayak manufacturer their kayaks also win a lot of medals.

Tom I think it was your follow up tweet that points out that some US warships also have a similar design of hull.

[Valgozi]

Can I add I so like design of the mobile phone case Nelo make - http://shop.nelo.eu/en/waterproof-phone-bag-and-holder.html

[thomas....@googlemail.com]

On Wednesday, November 30, 2016 at 9:46:29 AM UTC, Valgozi wrote:

Yup that was me, I had made the connection because I had just been reading about the warship when that photo pops up, although just to clarify AFAIK the hull design for the warship is more about anti-radar than any performance benefit - it does show the unusual bow design tho

I had a chat with Mr Fraga when I was in Turin, the impression I got is they only have the lightweight man hull size at the moment and he's basically helping them as a "test pilot" testing and tweaking the design from outings to see what works best, so I think they may not have finished the design/gone into production yet - He mentioned an approximate price of 7000 Euro's for when they are up for sale

[Kit Davies]

Is the innovation a wave-piercing bow? I believe there are a few coastal
designs that use these, eg
http://www.sea-sabre.com/the_seasabre_range/coastal/c1-single/

Looks a nice boat though. The fin shape is interesting. Based on a kayak?

Kit

[Brian Chapman]

They have a rowing boat web site go to www.nelorowing.com I have the flyer from Copenhagen, says available after 1 Oct.

[madmar...@gmail.com]

The tumblehome bow shouldn't make a difference on flat water where the waterline is nice and level and in the same spot.

The design might have advantages in heavier waters as it will both pierce a wave differently and shed the water more quickly than a boat with a larger flat deck area. You might equally argue that piercing waves that deeply isn't a good idea (see fuller bow above waterline on a Carl Douglas).

Not sure if there is any particular aerodynamic benefit since it is only for such a short length of the boat.

[gsl...@gmail.com]

No bow ball shown on neither the Sea Saber nor the Nelo 1x.

There is a local rower who has a custom open water boat with a similar bow. It also doesn't have a bow ball. It is a Doug Kidder design and I think was made in the Maas shop. Doug used to own Maas. Very nice looking boat with an empacher bow mounted rigger. Can't race it on flat water because of the lack of the bow ball.

[gsl...@gmail.com]

On Wednesday, November 30, 2016 at 9:54:27 AM UTC-8, gsl...@gmail.com wrote:
> No bow ball shown on neither the Sea Saber nor the Nelo 1x.
>
> There is a local rower who has a custom open water boat with a similar bow. It also doesn't have a bow ball. It is a Doug Kidder design and I think was made in the Maas shop. Doug used to own Maas. Very nice looking boat with an empacher bow mounted rigger. Can't race it on flat water because of the lack of the bow ball.

In all fairness, the picture of the Nelo 1x doesn't show a seat, foot stretcher, nor oarlocks, so the lack of bow ball is to be expected.

[Henry Law]

On 30/11/16 15:44, Brian Chapman wrote:
> They have a rowing boat web site go to www.nelorowing.com

It's very, er, green ...

[thomas....@googlemail.com]

Check the photos of the boat racing, it has a bow ball....

[Valgozi]

It seems the cad design team at Nelo had the same colour pallet as the ErgStick ;-)

[rolyb...@googlemail.com]

>
> They have a rowing boat web site go to www.nelorowing.com I have the flyer from Copenhagen, says available after 1 Oct.

There is rather more on the website than when I last looked. The boat seems to make a very narrow bow wave. Is that my ignorance, a marketing trick or a clever design?
Roly

[Steve S]

I could be mistaken, but I suspect this discussion has missed the point of the new Nelo design.

The discussion tends to the conclusion that the innovation in the Nelo design is a reverse bow: reverse in the sense that from its lowest point the stem is inclined towards the stern. This is the sort of reverse bow seen in some high-performance catamarans, some high-speed naval vessels, and a couple of the open-water racing boats.

However, this sort of a reverse bow is not in the photos of racers or the boat or in drawings on the website or in the Nelo patent application.

In the drawings, the bow profile shows a bit of a rocker, then a short vertical section, then _above the waterline_ , where the vertical bit ends, a slope back towards the stern. It would be fair to describe the stem as vertical, but not reverse.

The photos of the prototypes on the website and as rowed by Fraga at the Silver Skiff and by Fraga and Mendes at the Scullers Head seem to have even more of a vertical than the drawings in the patent application. This photo on the website is the most instructive
http://www.nelorowing.com/tech
This photo is consistent with the photos of Fraga at the Silver Skiff, here
http://www.fotoline.org/2016-Pagina%20Canottaggio/868-Torino-Silver%20Skiff-Regate/index2.html

While a reverse bow seems not to be the case, I suspect that the prototypes implement the feature that is described in some detail in the patent application. The art it teaches has to do with the shape of the transverse sections of the hull in the bow area. In a conventional design these sections have their widest point at the deck edge. In the Nelo patent, and probably in the prototype, these sections have their widest point very near the keel and then the width decreases continuously up to the deck. The section just aft of the bow is the most extreme; it looks like an elongated water droplet. And that extremely narrow bit is evident in the photos of Fraga. This tumblehome feature that Nelo calls "an inverted bow" extends about 1/4 of the length back from the bow, aft of which the section shapes are more or less conventional.

The patent claims four advantages of this design detail. (1) It asserts that the hull shape has greater directional stability. That is, this design would veer less to port or starboard in response to an unequal thrust from one side, or, perhaps, to a slight roll to one side. (2) It asserts that in the presence of alterations in trim or dynamic variations in buoyancy, the variation in waterline length is less than would be the case with conventional designs. (3) It asserts that the reduction in volume above the waterline is reflected in a reduction of air resistance, and (4) It asserts that in response to waves (implicitly, the waves that are encountered in flat-water racing), the boat pitches less.

Interesting.

[thomas....@googlemail.com]

"I could be mistaken, but I suspect this discussion has missed the point of the new Nelo design."

No your description matches what I see and what I tried to describe in my second post above, despite the narrowing of the bow above the waterline, below the waterline it looked relatively similar to any other boat - as you say the main difference is that above the waterline the hull narrows as it goes up to the deck, where as most boat widens to the deck being the wisest point

The distinction is important I feel as one comment I heard a couple say even there was the lack of bouyancy in the bow would cause a lot of bounce, but i think as below the waterline it's more conventional then that wouldn't be the case (and doesn't seem to be the case seeing it racing)

[jd2...@gmail.com]

The design appears similar to the Hudson " Super Predator" design, if not more pronounced in the shape and length of it's bow.  

Our club owns a Hudson S2.11, a 115-145 lb double which is extremely narrow and long in the bows. It looks like a 260 lb single made into a 2x. Very popular boat for the light women.

John Davis

[johntru...@gmail.com]

On Tuesday, 29 November 2016 16:53:14 UTC, thomas....@googlemail.com wrote:

Hi Everyone, we now have a demonstrator Nelo 75 kg crew weight single scull available to try at Maidenhead rowing club. We showed it at National Schools regatta last weekend and received lots of positive comments. The hull has an innovative design taken from knowledge and R&D from kayaks which as I counted ot won 27 of the 36 available kayak medals at Rio so they know something about hull design and making quality carbon fibre based boats. Please e mail me if you would like more information or have any questions Thanks John truswell

[Henry Law]

On 30/11/16 10:48, thomas....@googlemail.com wrote:
> Yup that was me, I had made the connection because I had just been reading about the warship when that photo pops up, although just to clarify AFAIK the hull design for the warship is more about anti-radar than any performance benefit - it does show the unusual bow design tho

Latest from the there's-nothing-new-under-the-sun department:

http://www.lawshouse.org/rowing/images/PNW-0158A.JPG

This is an exhibit in the Vancouver Museum of Anthropology. The
associated blurb calls this a "Sturgeon-nosed canoe" and goes on to say:

"Ktunaxa people have inhabited the Kootenay and Columbia rivers and the
Arrow Lakes region of British Columbia for more than ten thousand years.

"They are renowned for their distinctive 'sturgeon-nosed canoes'. The
boats unique flat-bottom design tapers at both ends, creating a
streamlined shape that cuts easily through the water. Sturgeon-nosed
canoes were traditionally made from birch bark, western white pine bark,
cedar wood, cedar roots, maple sap and pitch. Their light construction
made for easy transport on lakes and marshy wetlands. Today
sturgeon-nosed canoes are made primarily by the Yakan Nukiy people, also
known as the Lower Kootenay Indian Band." (sic: I understood that native
American peoples don't like to be called "Indians").

Does this count as prior art in respect of the patent application from
Nelo, I wonder.

--
Henry Law n e w s @ l a w s h o u s e . o r g
Manchester, England

[carl]

There is a patent application?? That really would be pushing their luck.

So-called wave-piercing bows go back for centuries and in all variants.

But I had not seen that Sturgeon bow canoe before, so many thanks for that.

Cheers -
Carl

--
Carl Douglas Racing Shells -
Fine Small-Boats/AeRoWing Low-drag Riggers/Advanced Accessories
Write: Harris Boatyard, Laleham Reach, Chertsey KT16 8RP, UK
Find: tinyurl.com/2tqujf
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[Steve S]

> There is a patent application?? That really would be pushing their luck.

Yes, there is a patent application. It in Portuguese, and here is the URL for the full application
http://www.nelo.pt/images/uploads/15-0385PT.pdf

A page of the Nelo website is headed "Nelo patents revolutionary design", that may be a translation error or a bit of marketing. Though the application is dated February 27, 2015, it seems to be still in the application stage ("Estudo suspenso").

Now...

>
> So-called wave-piercing bows go back for centuries and in all variants.

There seems to be a misconception of Nelo's ideas. The bow profile is vertical. It is not the "reverse" profile one sees in the beautiful Ktunaxa canoe (thanks Henry!), and also in some of the costal rowing boats one sees in Fisa events. A good image of the Nelo bow profile is here http://www.nelorowing.com/tech.

What is special about the Nelo design is the distribution of area in the bow: there is more low and less high. The sections just aft of the bow have a quite tear glass shape (c.f. patent application, figure 6, sections A and B). Here is my translation of the top claim: "A racing boat with the characteristic that in the bow region, the beam width corresponding to any water line of a vertical section has its maximum value substantially close to the keel and is continuously reduced to the deck."

These bow area section shapes are a complete contrast to the standard ones. In most boats the bow sections are widest at the deck and narrowest at the keel. Someone at Nelo chose to use the word "reverse" to characterize this contrast, and that is how the misconception arose. Repeating, then, it is the section shape that is reverse of the standard, not the bow profile.

The Nelo designers have convinced themselves that this bow configuration has several advantages. Among them:
- More volume in the bow area means less pitch at the front end and that makes it easier to optimize the catch
- The boat has less rocker, and so a better run and better directional stability
- More immersed volume forward contributes more stability in roll, allowing a designer to reduce stability aft of the bow area, with a consequent reduction in wetted surface and so friction resistance
- The prismatic coefficient is greater, and so less wave resistance

My guess is the reduction in resistance is minimal, but the other features are intriguing.

Fraga and Mendes have had success with the new boats in long races last fall. It would be nice to see one lining up at a World Cup.

Should anyone bring a boat to the San Francisco area, I would love to try it out.

[sander]

Better directional stability and less roll would be very interesting. I think anything that improves the boat stability and makes it easier to Row in chop without impacting resistance would lead to faster boats, potentially different single scullers winning races

[carl]

> ---
> This email has been checked for viruses by AVG.
> http://www.avg.com
>

What determines pitch stability is the rate of change, with angle of
pitch, of the integral of immersed cross-sectional area x distance from
centre of buoyancy, to bow & to stern. Clumsily put, in haste, but I
trust it's clear enough?

If the waterline beam far from the centre of buoyancy is already small,
& may even be tapering inwards as waterline rises, that reduces, not
increases, the hull's pitch resistance. The volume which is already
underwater provides only a fixed amount of uplift regardless of how
deeply it is immersed.

[Steve S]

Regarding the pitch implications, here is an explanation from the patent application ( with my apologies in advance for any translation errors)

"The present invention enables, due to the shape of the bow, an increase in the length of the water line. As previously mentioned, the length of the water line always remains at maximum, even when there is variation of the trim.
Considering that in this form of hull there is a greater volume submerged in the bow - when compared with so-called conventional models -, as soon as there is a tendency for the prow to leave the water the variation of immersed volume is bigger, provoking a negative moment that forces it to return to the ideal position, maintaining the shape of the water line."

[thomas....@googlemail.com]

Well it looks like the first one at a World Cup will be racing this weekend in lucerne, pictures have gone up of Milos Stanojevic from Serbia racing in the men's lightweight single. Previously Bronze medalist at the worlds in 2015, 6th in the B final at the last World Cup, will be interesting to see how he gets on and will make different viewing from the usual yellow/white flotilla if he makes the A final and the race is filmed

[carl]

In a way, Stephen, that's the same argument that I rather clumsily
presented & it doesn't lead in the direction claimed. The inverse taper
of the upper part of the immersed cross-section means that a relatively
large change in pitch will generate only a rather small correcting moment.

You see this at work with any catamaran with wave-piercing-style bows,
even when stationary. Thus I'm aware of more than one incident in which
a coaching catamaran launch was rescuing the crew of a capsized W4x (how
you capsize a 4x is a question for another day).

The cat was a tad over-loaded with crew at the time. One bow was
accessible to a swimmer who tried to climb onto it, which markedly
reduced that bow's freeboard. A supernumerary member of the cat's crew
started to move forward to help to extract the swimmer, whereupon the
bow dipped under.

Had the swimmer not slipped off at that moment, & had the cat crewman
not promptly retreated (a movement that, if too sudden, would also have
tended to dangerously depress the bow), the total loss of righting
moment consequent on the full immersion of that bow (so that any
increase in pitch would generate no additional uplift) would have caused
the cat to further bury that bow and roll right over.

Similarly, a fully-submerged submarine has rather little pitch stability
unless moving - in which case the hydrodynamic forces on its control
planes can fully stabilise it. A fair explanation of submarine-hull
stability factors is given here:

www.marineinsight.com/naval-architecture/understanding-stability-submarine/

So it's sad that, as so often in this hydro-dynamically (&
hydro-statically) rather naïve sport, irrational arguments are used to
justify design changes which may, or may not, provide advantages but, if
they do, do so for totally different & more complex reasons.

Cheers -
Carl
--
Carl Douglas Racing Shells -
Fine Small-Boats/AeRoWing Low-drag Riggers/Advanced Accessories
Write: Harris Boatyard, Laleham Reach, Chertsey KT16 8RP, UK
Find: tinyurl.com/2tqujf
Email: ca...@carldouglasrowing.com Tel: +44(0)1932-570946 Fax: -563682
URLs: carldouglasrowing.com & now on Facebook @ CarlDouglasRacingShells

[madmar...@gmail.com]

On Saturday, 8 July 2017 17:45:43 UTC+1, carl wrote:

> > Considering that in this form of hull there is a greater volume submerged in the bow - when compared with so-called conventional models -, as soon as there is a tendency for the prow to leave the water the variation of immersed volume is bigger, provoking a negative moment that forces it to return to the ideal position, maintaining the shape of the water line."
> >
> In a way, Stephen, that's the same argument that I rather clumsily
> presented & it doesn't lead in the direction claimed. The inverse taper
> of the upper part of the immersed cross-section means that a relatively
> large change in pitch will generate only a rather small correcting moment.
>
> You see this at work with any catamaran with wave-piercing-style bows,
> even when stationary. Thus I'm aware of more than one incident in which
> a coaching catamaran launch was rescuing the crew of a capsized W4x (how
> you capsize a 4x is a question for another day).

There are a great many videos of the modern America's Cup catamarans doing exactly what Carl is talking about in both racing and training.

Once that bow digs in to a wave or some wash (one of the training examples was an 'own goal' caused by the team high speed RHIB) it has no way of holding itself up and it just keeps on digging, with a nosedive followed by a capsize the usual outcome.

[gsl...@gmail.com]

Carl,
Everything you said is true but irrelevant to the quoted claim. If you read the quote again more carefully, there is nothing wrong with it as written. It says there is more submerged volume in the bow when compared to other boats. It does not say anything about what is above the water line. It also is referring to what happens when the bow raises not lowers.
It is perfectly true that if you move submerged volume from mid hull to the bow, then when you move to the catch, and the bow will lift less than in a conventional boat.
One could achieve the same effect by having a hull whose width at water line was constant over the whole length. It would be a terrible design but it would pitch less. So the claim may be true, but that does not necessarily make the boat faster or better. And as others have noted the photos of the single don't look like they have a wave piercing bow.

Additionally any boat that is FISA compliant cannot have a proprietary hull design. I would agree with Carl to beware of hype.

[carl]

On 10/07/2017 01:35, gsl...@gmail.com wrote:
> Carl,
> Everything you said is true but irrelevant to the quoted claim. If you read the quote again more carefully, there is nothing wrong with it as written. It says there is more submerged volume in the bow when compared to other boats. It does not say anything about what is above the water line. It also is referring to what happens when the bow raises not lowers.
> It is perfectly true that if you move submerged volume from mid hull to the bow, then when you move to the catch, and the bow will lift less than in a conventional boat.
> One could achieve the same effect by having a hull whose width at water line was constant over the whole length. It would be a terrible design but it would pitch less. So the claim may be true, but that does not necessarily make the boat faster or better. And as others have noted the photos of the single don't look like they have a wave piercing bow.
>
> Additionally any boat that is FISA compliant cannot have a proprietary hull design. I would agree with Carl to beware of hype.

Actually, I must politely disagree.

What determines the tendency of any hull to pitch, or not, is the rate
of change of righting moment (in the pitching direction) with angle of
pitch, & that is proportional to its rate of increase or reduction in
displacement (remote from the centre of buoyancy) with pitch angle.

In slightly more detail:
It is the rate of change, with angle of pitch, of the integral of
waterplane beam x distance from the hull's centre of buoyancy that is
the absolute determinant of pitch stability/stiffness. Pitch stability
is completely unaffected by the distribution of submerged volume along
the boat. So the narrower the waterplane beam at a distance from the
centre of the boat, the more prone that boat will be to pitching.

Thus a boat with a tear-drop cross-section immersed to below the widest
part of that teardrop (exaggerating to make the point!), undergoes
smaller changes in local displacement & hence in overall righting moment
with change in pitch than one with vertical sides, & smaller still than
one with a Vee-shaped above-water cross-section. And when promotional
literature claims the exact opposite one has to question the overall
design logic.

As I'd said before, the extreme case is the submerged submarine, where a
change in pitch causes no change in distribution of local displacement &
hence no pitch-correcting moment.

Cheers -
Carl
--
Carl Douglas Racing Shells -
Fine Small-Boats/AeRoWing Low-drag Riggers/Advanced Accessories
Write: Harris Boatyard, Laleham Reach, Chertsey KT16 8RP, UK
Find: tinyurl.com/2tqujf
Email: ca...@carldouglasrowing.com Tel: +44(0)1932-570946 Fax: -563682
URLs: carldouglasrowing.com & now on Facebook @ CarlDouglasRacingShells

---

[gsl...@gmail.com]

On Tuesday, July 11, 2017 at 9:06:34 AM UTC-7, carl wrote:

> In slightly more detail:
> It is the rate of change, with angle of pitch, of the integral of
> waterplane beam x distance from the hull's centre of buoyancy that is
> the absolute determinant of pitch stability/stiffness. Pitch stability
> is completely unaffected by the distribution of submerged volume along
> the boat. So the narrower the waterplane beam at a distance from the
> centre of the boat, the more prone that boat will be to pitching.

Yes, and if move the volume from the center to the bow by making the waterplane beam wider, you increase the stability, and that is how I interpreted it. But you are correct, it at the very least unclear and perhaps completely wrong--I only glanced at the drawings.

[carl]

I went only on the text, which certainly seemed wrong.

Sometimes people write nonsense - 'cos and they just have to over-egg
the promotional pudding.

[Steve S]

Got to hand it to Google, from time to time.

Here is the English version of the Nelo patent application

https://google.com/patents/EP3067268A2?cl=en

The drawings won't show up on my browser, but they are in full in the Portuguese version of the patent application, which is here

http://www.nelo.pt/images/uploads/15-0385PT.pdf

[magg...@gmail.com]

Hi Steve,

Just as an informational point of interest; Nelo has a reseller in California that has just brought over 2 singles and a double. The boats are in the San Fran area.

Www.nelous.com

[gsl...@gmail.com]

link not working

[Steve S]

Worse than not working, it links to something that has nothing to do with Nelo. The referenced boats came in to the Nelo Kayak/Canoe rep in San Diego, California, and then as far as I can figure out to the Stanford U boathouse for tryout. For pictures go to Jan 30, 2019 on the facebook link https://www.facebook.com/nelousa/

[eray...@gmail.com]

Hi, the link is working, as well as the FB page. The demo boats are in Newport Beach area at the moment.