Exciting New EPS Thruster (& Propulsion)

[brian eiland]

The results of the Design at METS awards, announced at this morning's
Breakfast Briefing, appear to prove that the wheel can be reinvented
according to the Jury, who named the EPS Silent Thruster from Van der
Velden Marine Systems (http://www.vdveldengroup.nl/) of the Netherlands as the overall winner.

This product redefines the bow thruster, eliminating the usual arrangement
of a central hub and gearbox. It instead uses exchangeable blades that are
connected to an outer ring; this floats on ceramic bearings and is powered
by an integral motor in the casing. The solution is elegant, well designed,
and promises a number of advantages over conventional concepts
_________________________
....from their website...

In addition to fixed thrusters they are now working on retractable systems as well as
utilizing the concept of the EPS as a means of propulsion !!

[brian eiland]

When I saw this new technology this morning my thought drifted back to some patents I had collected a number of years ago when I was researching some alternative marine propulsion drive systems prior to my command of a computer....just good old looking thru the stacks of patents down at the patent office.

I'll post a couple of these, and maybe someone will update this subject thread with more examples obtained by computer wizardry.

I imagine that one of the primary technologies that allow this new 'peripheral
drive' to come into being is the fantastic new ceramic bearing technologies.

Examples:
1) Patent #3,487,805 Jan 6,1970
PERIPHERAL JOURNAL PROPELLER DRIVE

2) Patent #5,181,868 Jan 26,1993
JET PROPULSION DEVICE FOR WATERCRAFT.....AND CIRCULATING PUMPS

[brian eiland]

....I imagine that one of the primary technologies that allow this new 'peripheral drive' to come into being is the fantastic new ceramic bearing technologies.
As I look a little closer I still do not see what "EPS" stands for??....maybe 'electronic pulsed system'

Maybe the bearings aren't all of the technology that has allowed the emergence of this new propulser. It appears as though the preipheral drive power is an electric motor of some sort integrated into the outer ring. This would make sense with all of the new talk of diesel/electric systems.

[brian eiland]

Over on another forum there appeared this notice of some other work on "Rim-Driven Propeller" units (http://www.yachtforums.com/forums/news-products-and-launches/3823-rim-driven-prop.html)

[brian eiland]

I originally posted a notice of this 'exciting new EPS Thruster' award under the Diesel Electric Propulsion subject thread, but I thought it might do to cross-link the subject threads as this thruster (bow) technology might well lead to propulsion technology. I noticed also that the EPS subject was rather more difficult to find on their website so I've attached their PDF file. (opps, had trouble uploading file....you need to go to their site and go to "news", and click on "EPS Silent Thruster")

From the latest issue of The Yacht Report there is a new product news release. "Voith told Project 2004 delegates last year of an impending sea trial experiment using VSPs (Voith Schneider Propellers) for roll stabilisation; the "VSR" concept. Although not currently available, the results must have been satisfactory as they will supply their first Platform Supply Vessel (PSV) with VS units to both propel and stabilise the 85m vessel. The stabilisation works under way and at anchor or rest. Ever technically innovative, Voith is also entering into a commercial cooperation with another innovator, AIR Fertigung-Technologie GmbH. AIR have sold composite automatically adaptive pitch Carbon Fibre propellers to the superyacht market, but will now offer electrically rim driven propulsors from 0.2 to 200 kW. These can be transverse or azimuthing thrusters, or main drive pods azimuthing or fixed. Their transverse thruster strongly resembles the Van der Velden EPS rim driven thruster. This is apparently not coincidence as Dirk Bucher of AIR told me that the two companies were until recently working together on that project."
http://www.voithturbo.de
http://www.air-composite.com

I underlined that one phrase as it caught my attention that this technology might well morph into propulsion units after thrusters.

[Guillermo]

Brian,
I find this EPS thing as main propulsion very interesting for a variety of boats and ships. Here a more direct link to the Rim Driven Thrusters you mention:
http://www.brunvoll.no/Web/resources.nsf/0/0F5A219AA75C9EC4C1257083002E22F7/$FILE/Brunvoll_developes_RDT.pdf

I find the RDT specially interesting for big stern trawlers like the Danish one attached. Main Engine power for this ship is 4860 kW and total electric power staggers to a huge 4996 kW! Of these, 3060 are driven by the main engine.
I believe the use of diesel electric in conjunction with one big RDT may bring great advantages for this kind of ships.

[brian eiland]

That's a very interesting document (http://www.brunvoll.no/Web/resources.nsf/0/0F5A219AA75C9EC4C1257083002E22F7/$FILE/Brunvoll_developes_RDT.pdf). I suspect that the one area that is going to be most demanding in the development will be the bearings. They quote;

"The bearings of the RDT are designed to eliminate the need for lubrication oil and there are no dynamic seals. Hence, the bearings, which are both magnetic and hydrodynamic bearings (with patents pending), are designed to minimise maintenance costs and eliminate any oil pollution."

I suspect, but don't know, that these might be some sort of ceramic bearings. Just think of the thrust loads imposed on the 'ring' supporting the blades that must also maintain electro/magnetic tolerances, and often in 'dirty water'!

[Guillermo]

Yes,
The question is what's the upper power limit with this technology. They have tried 100 kW, but when we are talking about 5000....(?). Very interesting matter, deserving a close follow up for next improvements and bigger models developing.

[brian eiland]

Looks as though there are a few players in this technology, and Brunvoll appears as a front runner having done some considerable big scale prototyping and testing.

Interestingly it appears as though the relatively new permanent magnet electric motor technology has driven this new interest in rim-drive propulsion. From Brunvoll," the development of RDT has been triggered by market demand for an increased number of ships where both the main propulsion units and the manouevering thrusters have electric motors with variable speed drives. In this context the RDT offers a number of advantages."

So rim drive propulsion is advancing right along with the thruster development. Brunvoll has worked together with the company Norpropeller to test a novel drive system for variable speed electrically driven propellers. This system involves the use of variable speed permanent magnet generators and PM motors. The design implies that the prime mover, the diesel engine, can be run as in a traditional system, as if the engine was direct mechanically coupled to the propeller, but not requiring a reduction gear, nor a battery storage source.

Brunvoll is planning to market the RDT for ships and larger craft, while Norpropeller will focus on the market for smaller craft

Another player, AIR Fertigung-Technologie GmbH, that have sold composite automatically adaptive-pitch Carbon Fiber propellers to the superyacht market will now work to provide electrically rim driven propulsors from 0.2 to 200 kW.

Lets add some pictures of the Brunvoll test unit.

[nero]

kinda thought the advantage of having a battery bank meant that the diesel engine could be small in size.

In 4 years they should have it all worked out for my catamaran. fingers crossed.

[brian eiland]

....Another player, AIR Fertigung-Technologie GmbH, that have sold composite automatically adaptive-pitch Carbon Fiber propellers to the superyacht market will now work to provide electrically rim driven propulsors from 0.2 to 200 kW.
I received a PDF document from this company just the other day, and it certainly looks as though they are persuing the smaller unit sizes we might utilize in yachting vessels verses commerical boats, 4-100kW.

From the PDF, "The Inline Thruster, as a compact unit, can be installed subsequently at any time as a bow or stern thruster, or soon as main or auxilary drive"

I noted from the PDF document you sent me previously, "the mounting of the rotor is realized by proven water lubricated floating bearings...".

I did not detect any substantial indication on the drawings of proper thrust-load bearings?? These bearings are going to see much higher loads than the peripheral bearings.

And in the case of a main or aux drive unit, as opposed to the thruster units, both of these bearings are going to experience more 'heated operation' as a result of the continuous rather than intermittent loading. Can you comment on these questions and/or offer any discussion of these bearing problems/details.

Your 'floated box' solution to the servicing accessability looks very nice.

[brian eiland]

I noted from the PDF document you sent me previously, "the mounting of the rotor is realized by proven water lubricated floating bearings...".

I did not detect any substantial indication on the drawings of proper thrust-load bearings?? These bearings are going to see much higher loads than the peripheral bearings.

And in the case of a main or aux drive unit, as opposed to the thruster units, both of these bearings are going to experience more 'heated operation' as a result of the continuous rather than intermittent loading. Can you comment on these questions and/or offer any discussion of these bearing problems/details.

An email response from the manufacturer brought this;
"Concerning the bearings we had developed a special bearing with different functions. It is mainly designed for the continous loading of the thrust. It has no problems with the continous loading typical for propulsion units. The intermitted loading is covered by another bearing and optimised for this. At the drawings you can not see the details."

and, "The inline jet is an electrical rim driven propulsor. At the moment we offer this system in two sizes. The third size will start in this year. It can used for thruster applications and propulsor applications as well as retractable installations."

[Guillermo]

Maybe the thrust bearings issue is why they are limiting power for the time being. I'll try to get more info from them to know their plans to develope higher powers, as it would be a nice propulsion system for modern stern trawlers and other fishing and work vessels.

[Deering]

What happens with this unit when a log or other debris goes through it? What's the failure mode?

Seems to me that if an object gets sucked in, all of the carbon fiber blades get wiped out and you're dead in the water, vs a prop that might get dinged up but still provides limp-home capability.

[Guillermo]

Just to inform that on March the 18th I wrote to Brunvoll the following message:

"....I've known about your Rim Driven Thruster trough Boatdesign Forums and I'm very interested in knowing more about the system, as I find it may be applicable to stern trawlers and other fishing boats, as well as tugs, work boats, etc.
I see the power goes up only to 100 kW and I would like to know if you have plans to go up in the range. Is your thrust bearing system able to cope with higher loads?
I would appreciate very much your kind answer. Thanks in advance."


No answer till now. :confused:

[camglasgow]

Looks like RR are developing high-power units > 800kW.

See: http://www.rolls-royce.com/marine/overview/news/2005/newsitem12.htm

Are these 3-phase AC machines?

[brian eiland]

Looks like RR are developing high-power units > 800kW.

See: http://www.rolls-royce.com/marine/overview/news/2005/newsitem12.htm

Are these 3-phase AC machines?
Dear Camglasgow,
I'm going to suggest that you copy the text here rather than just a web reference. Too often in the past I have seen such 'momentary' press releases disappear from the web and leave a connecting web-link unsatisfied.

And no 3 phase AC I suspect, as these are 'permanent magnet' units
__________________________________________

Rolls-Royce introduces Rim Drive thruster technology

15 November 2005


Rim Drive thruster


The first commercial application of a new type of Rolls-Royce tunnel thruster launches a technology which will have a major impact on marine propulsion in the future.

Rim Drive is a tightly integrated system combining electrical, mechanical and hydrodynamic elements. The electrical motor takes the form of a thin ring. Its stator is incorporated in the tunnel and its rotor carries propeller blades that point inwards.

The first application is on an offshore support vessel, in the form of a tunnel thruster type RT1600 rated at 800kW. In due course the power range of rim tunnel thrusters will be broadened, and the technology will be used in other types of propulsor. The electro-mechanical part of the technology will also be applicable to winches, steering systems and other Rolls-Royce products.

This technology has been developed in Norway over a period of several years by Rolls-Royce in Ulsteinvik and Smartmotor in Trondheim working in close collaboration. A prototype unit has been subjected to function trials and long periods of endurance testing in Norway, and to detailed hydrodynamic evaluation in the cavitation tank at the Rolls-Royce hydrodynamic research centre in Sweden.

Several features combine to provide advantages for the owner, as R&T Project Manager Gunnar Johnsen explains.

"Water flow through the unit is unobstructed since there is no gearbox in the tunnel, nor are struts needed to support a hub. Propeller blades are attached to the rim, eliminating uncontrolled flow between blades and tunnel. The permanent magnet motor design is very efficient. Together these factors give a high total efficiency and reduced noise and vibration. Because more thrust is produced for a given power input, fuel consumption is reduced, and this saving can be substantial in applications such as offshore support vessels operating in dynamic positioning (DP) mode where thrusters may run for hundreds or thousands of hours a year. Fuel saving is not only a matter of money; the impact of the vessel on the environment is also reduced.

"The Rim Thruster is designed to be mountable and dismountable under water, so that it can be removed for servicing if required without drydocking the vessel. We use water-lubricated bearings, eliminating propeller shaft seals and oil-filled gear housings.

"The motor is an integral part of the unit in the tunnel, so the ship designer no longer has to find space for a bulky electric motor in a thruster room. The only parts of the thruster inside the hull are the cables connecting it to the frequency control supply cabinet. The cabinet is similar to that used with any frequency controlled electrically driven thruster, and its location is flexible."

Olympic Shipping, based in Fosnavåg in Norway, has ordered the first RT1600 for their UT 712 CD anchor handler now under construction at Aker Yards Søviknes. This vessel will have twin CP propellers for main propulsion, and other thrusters to give the station keeping power needed to meet IMO DP2 dynamic positioning standard. The rim drive unit will be installed in the aft skeg acting as a stern side thruster.

Helge Gjerde, President-Offshore Propulsion in Rolls-Royce said, "We are delighted that Olympic Shipping is fitting the new thruster type to their latest vessel. As equipment manufacturers we are dependent on forward thinking shipowners to bring new products and systems to market. Olympic's UT 712L is also the first to fit the newly developed Rolls-Royce DP2 dynamic positioning system, and also the equipment for making work on deck safer."

Bjørn Kvalsund, operations director of Olympic Shipping, makes the point that, "Our background in fishing and offshore has shown us that good equipment is the key to success, and that investment in technology that increases efficiency pays off in the long term. We aim to provide our oil company customers with vessels suited to their present and future needs, not their past ones, and to offer fuel efficient vessels with low environmental impact. The safety and well-being of our crews is just as important, and equipment that produces less noise and vibration is a valuable contribution to this."

[jedclampit]

My only thoughts are the weight of these units (RIM's)...they have to be heavy mothers...but that's just my guess. A typical thruster config would weight less than 1/2 of these units...(thinking of small pleasure craft).

Jed

[Guillermo]

I've received an answer from Brunvoll:

"Reference is made to your e-mail dated 18.04.2006....

As you know we have built and tested a RDT with a power of 100 kW. As far as we know this is the largest RDT ever bulit in the world so far.

For your information we have now a contract to deliver a RDT with a motor power 810 kW. The unit is configured as a bow tunnel thruster and will be installed on board an OSV with DP Class Notation currently under construction for a Norwegian owner. This unit will be tested beginning of 2007.
As we are sure you understand this is still a "pilot installation". Successful application on board this ship will however be a large step in further proving the concept and the design features of the Brunvoll RDT...."

Knut Andresen
Technical Director
Deputy Managing Director
Brunvoll A.S

Phone : +47 71 21 96 00
Fax : +47 71 21 96 90
e-mail : knut.andresen@brunvoll.no
web site: www.brunvoll.no

[kach22i]

Over on another forum there appeared this notice of some other work on "Rim-Driven Propeller" units (http://www.yachtforums.com/forums/news-products-and-launches/3823-rim-driven-prop.html)
Awesome, I can see this making it's way onto larger hovercraft in an air screw version.

Like this:

The NASA version.

http://www.grc.nasa.gov/WWW/RT/2003/images/7720emerson-f1.jpg
http://www.grc.nasa.gov/WWW/RT/2003/7000/7720emerson.html

[brian eiland]

...just saw this in a press release...
"In addition to serving as an auxiliary bow and stern thruster, the wide range of benefits offered by the EPS opens up many other future applications," comments Van der Velden technical director Edwin van Buren. "With this in mind, our design and development activities will continue apace. We are currently looking at a fully retractable propulsion system for use onboard larger sailing yachts (leaving the hull undisturbed when sailing)."

(16 November 2006)

[Guillermo]

At the EPS presentation by Brunwoll and Norpropeller they proposed also an interesting combination of tunnel and azimut thruster. Revisit page two at:
http://www.brunvoll.no/Web/...... (http://www.brunvoll.no/Web/resources.nsf/0/0F5A219AA75C9EC4C1257083002E22F7/$FILE/Brunvoll_developes_RDT.pdf)

[brian eiland]

..As you know we have built and tested a RDT with a power of 100 kW. As far as we know this is the largest RDT ever bulit in the world so far.
Just found this PDF, Design of an Integrated 100kW Permanent Magnet Synchronous Machine in a Prototype Thruster for Ship
"An alternative solution is a rim driven thruster where the shaft and gear has been removed. There are only propeller blades in the water path and only electric cables go through the hull. This improves the efficiency of the propeller, removes the gear and reduces vibration. In this paper the design of an integrated electric machine is presented together with results from the testing of the electric machine. Bearings, hydrodynamics and noise are not discussed"

Can anyone add anything new?

Obviously I really interested in the full development of these propulsers as I want to put a couple of them on my gamefishing catamaran
Offshore Sportfishing Motorsailer, innovations & alternatives
http://boatdesign.net/forums/showpost.php?p=116104&postcount=2

[Pericles]

Brian, Have you seen this from the JetPac distributer in the UK?

http://www.fleetwatermarine.com/carbon_fibre_thrusters.htm

Carbon fibre 'Ring' Thrusterscarbon_fibre_ring_thruster

As with our carbon fibre propellers, conventional marine thruster units have changed little over the years. Most are essentially small shaft mounted propellers, but now we have designed a unique lightweight, low noise Ring thruster unit with individually replaceable carbon fibre blades.

Carbon fibre Ring thruster - Design

The Ring thruster comprises a circular housing containing an electric motor with carbon fibre propellers mounted on the interior of the ring. The design has many advantages over conventional propulsion units.

* The ring thruster in compact - saving space
* No additional gear box required - saving cost and weight
* No cavitation - reducing noise and improving efficiency
* No propeller fouling - Ropes and obstruction pass straight through the middle of the thruster
* Improved acceleration - particularly under high load
* Blades are mounted in a water cooled, ceramic seal - Avoiding blade degradation.
* No overheating - Entire housing and engine cooled by surrounding water

Thruster Propellers - the thruster with exchangeable blades

Each thruster unit is fitted with separate exchangeable blades, constructed of advanced high strength carbon fibre materials. In the event a blade is damaged it can easily be removed and replaced without the expense of replacing the entire propeller.

Pericles

[brian eiland]

Brian, Have you seen this from the JetPac distributer in the UK?
I had seen that, and I made an inquiry to them in the UK and their USA representative...so far no response. I suspect they are planning to market another's technology for the electrical motor portion of the unit while they supply the carbon blades they specialize in....just my hunch.

[Pericles]

The Steam Engineers amongst you all, will be familiar with steam injectors.
http://en.wikipedia.org/wiki/Steam_injector

"The principle of the device is that steam is passed through a series of cones which reduce its velocity and temperature while increasing its pressure. Fresh water from the tender or tank is entrained in the fast-moving initial steam jet by Bernoulli's principle, and the mixture passes into a convergent "combining cone" which mixes them thoroughly. The steam and water mixture then enters a divergent "delivery cone" which slows down the jet, condenses most of the steam and builds up the pressure of the mixture to above that of the boiler. There is a one-way ball valve at the exit of the injector which only allows the water to enter the boiler when its pressure is high enough."

Rather than using the high pressure water (250 lbs per sq inch) to feed the boiler, why not jet it out at the stern to drive a boat?

Ignoring the jokers who are even now visualising how to shoehorn a UP Challenger into a Tolman skiff, :D :D I am I nterested to know whether the sums could add up, by entraining cold sea or river water to create the thrust. I think the water jet temperature will be only luke warm and make a great swim platform shower.

Gentlemen, start your calculators!:P

[marshmat]

Re: Kach22's post in #20
Interesting to see magnetic bearings show up there. Such a fan would not be subject to the wear and balance issues that crop up with high-precision mechanical bearings; provided the rotor itself is well balanced the only real limit to rotation speed would be the need to keep the blade tips subsonic. Probably a lot cheaper than the bearings used in jet turbines to reach this kind of speed....
Re: Pericles in #26
Something like Pursuit Dynamics' drive http://www.pursuitdynamics.com/marine.php ? Seems to be a similar concept but nobody outside the company seems to know just what the thing looks like inside, so I can't say exactly what goes on inside it other than it's based on a supersonic shock wave created by the suddenly condensing steam.

[kach22i]

I remember the water jet being posted before, nice to see that it's still progressing.

[brian eiland]

...just saw this in a press release...
"In addition to serving as an auxiliary bow and stern thruster, the wide range of benefits offered by the EPS opens up many other future applications," comments Van der Velden technical director Edwin van Buren. "With this in mind, our design and development activities will continue apace. We are currently looking at a fully retractable propulsion system for use onboard larger sailing yachts (leaving the hull undisturbed when sailing)."

(16 November 2006)
Recently received these new images on retraction. Personally I don't care for the volumn of water carried along in this 'waterbox'.

[brian eiland]

Awesome, I can see this making it's way onto larger hovercraft in an air screw version.
Like this:

The NASA version.
http://www.grc.nasa.gov/WWW/RT/2003/...20emerson.html

Your magnetic turbine posting came to mine when I was looking for rim-drive propulsion concepts operated in reverse....as generators of electrical power in high tidal/current zones.

I ran across this interesting site:
http://www.openhydro.com/home.html

[marshmat]

Personally I don't care for the volumn of water carried along in this 'waterbox'.
Agreed... any production model would have to have a retraction housing that is a fairly tight fit around the retracted drive. As drawn there, the housing holds about three tonnes of water when the drive is extended, a pretty significant load. The main reason is that the housing drawn is rectangular; by fitting the housing as tightly as possible around the retracted drive (circular where the prop comes up, and no excess water space around the strut) they could probably bring the entrapped water volume down by half.

[brian eiland]

I noted the use of 'magnetic levitation bearings' in the NASA air turbine unit.

In many cases magnetic levitation has often appeared as an unecessary complication to new products. Imagine the loads that the 'magnetic' thrust bearings would have to resist with the air-turbine.

So far I believe at least one of the rim-driven propulsers are utilizing ceramic bearings. Something I have yet to see in a actual use is the 'Near-Frictionless Carbon" bearing material developed in our national labs
http://www.anl.gov/Media_Center/News/2005/news050610.html
http://www.spacedaily.com/news/materials-02ze.html
http://www1.eere.energy.gov/vehiclesandfuels/pdfs/success/near-frictionless_carbon.pdf

[kach22i]

Your magnetic turbine posting came to mine when I was looking for rim-drive propulsion concepts operated in reverse....as generators of electrical power in high tidal/current zones.

I ran across this interesting site:
http://www.openhydro.com/home.html

Cool, so that's what the future looks like.:)

[brian eiland]

I extracted this new view of a rim drive unit from a document recently sent to me

[brian eiland]

...introduction to the paper

Structurally Integrated Slotless PM Brushless Motor with Spiral Wound Laminations for Marine Trusters

Abstract:

Rim driven thrusters with structurally integrated brushless PM motors are now an established technology with an increasing range of applications. In these thrusters, the stator of the motor is housed within the thruster duct, and the rotor forms a ring around the tips of the propeller. Such high pole number motors tend to be very thin radialy, have very small length to diameter ratios, and have relatively large airgaps to accommodate corrosion protection layers on the surfaces of the rotor and stator. The relatively large diameter stator laminations of such machines tend therefore to have very thin back of core and narrow teeth, which make them expensive and difficult to manufacture.

This paper proposes an alternative potentially lower cost motor topology featuring a slotless stator whose laminations are manufactured from a single strip of steel that is edge wound into a spiral (like a “slinky” and then fitted over the windings that are preformed on the outside surface of a non-conducting former. The former is also part of the sealed housing that protects the stator from corrosion in seawater.

The paper discusses the design optimisation of such a motor using analytical and finite element analysis (FEA), describes a demonstrator motor and reports experimental and FEA results.

[kach22i]

What's the best way to get juice to something like that?

[Guillermo]

I think there is an ample array of applications for rim thrusters, ranging from main propulsion to auxiliary thrusters, in all kind of vessels.
I'm interested in high powered ones for ships propulsion, specially for big trawling FV and tugs.
Cheers

[marshmat]

What's the best way to get juice to something like that?
Dilithium-crystal warp core, of course.
Actually I was thinking more along the lines of a solid-oxide fuel cell stack, would be a good match for a ship- they take a couple hours to get up to peak efficiency, but that peak efficiency is more than double that of a good diesel (60% versus 30 or so). SOFCs love a steady, constant load- like that of a ship's drivetrain- and the extra bulk compared to the PEMFC type used in fuel cell cars isn't an issue in a ship's engine room.

[kach22i]

Actually I was thinking more along the lines of a solid-oxide fuel cell stack
That just requires hydrogen and oxygen, right?

Are there any Fuel Cells which use Diesel fuel or E85?

I found this earlier today, cool.:cool:
http://history.nasa.gov/SP-4002/p1b.htm
http://history.nasa.gov/SP-4002/images/fig12.jpg
Figure 12. The operating principle of the fuel cell designed by General Electric, adopted for use in the Gemini spacecraft. (McDonnell, "Project Gemini Familiarization Charts," June 5, 1962, unpaged.)

[marshmat]

Hydrogen and oxygen, yep. The latter's easy to get, the former's a royal pain in the butt to store though.
There are "direct-methanol" fuel cells, currently being developed for laptops and cellphones, which work directly off the simpler methanol (methyl alcohol). No larger versions that I know of can do so.
Heavier fuels such as diesel oil, at present, must first be converted into hydrogen and carbon dioxide, often by high-temperature steam. Although this defeats the zero-emissions advantage of the fuel cell, the CO2 released is reported to be somewhat less than produced by a combustion engine of comparable power, due to the fuel cell's substantially better overall efficiency and thus its lower fuel consumption. (The waste steam from the cracking process and the steam that is the exhaust of the fuel cell can be used to spin turbines, improving the overall system efficiency.)
I have heard of research into SOFCs that might be able to catalyze a liquid fuel into hydrogen internally, but I haven't seen a working model yet.

[kach22i]

There are "direct-methanol" fuel cells, currently being developed for laptops and cellphones, which work directly off the simpler methanol (methyl alcohol).

The "E" in E-85" is ethanol which is a type of alcohol, right?

http://en.wikipedia.org/wiki/E85
E85 is an alcohol fuel mixture that typically contains a mixture of up to 85% denatured fuel ethanol and gasoline or other hydrocarbon by volume.


Are there any Fuel Cells which use ethanol?

FYI: I started a simlar topic in a Physics Forum;
http://www.physicsforums.com/showthread.php?t=182242

[marshmat]

E-85 is 85% ethanol (ethyl alcohol, CH3CH2OH), and 15% gasoline. Ethanol is also, coincidentally, the intoxicating agent in beer and liquor, although the gasoline blend will not make you drunk- just really, really sick.
Methanol (methyl alcohol, CH3OH) is used as a fuel in race engines and, now, in small fuel cells. It is not drinkable (causes blindness).

[brian eiland]

Might I make a suggestion that the subject of alternative fuels be carried on at other 'fuel threads', or even on its own individual subject thread.

It is a BIG subject in its own right.

And there are lots of controverses about the subject of E85 that would drown out the subject at hand, 'rim drive propulsers'.

Thanks for your considerations, Brian

[brian eiland]

Rolls Royce has posted a few new PDF documents

http://www.rolls-royce.com/marine/downloads/article/id9_rimdriven.pdf
http://www.rolls-royce.com/marine/downloads/propulsion/prop_broc.pdf

[brian eiland]

Curtiss-Wright Electro-Mechanical Corporation
CW-EMD's unique motor technology has led to other product innovations. Our Integrated Motor Propulsor System integrates a number of advanced technologies, a unique canned induction motor, material selection and deployment flexibility. The development and qualification program for this rim driven propulsor was so successful that the prototype unit was used without any post-testing modification or refurbishment.

A similar product innovation utilizing our canned motor technology is the hazardous waste pump. This integral submerged canned motor/pump eliminated the need for externally supplied cooling and lubricating systems. The long-life, highly reliable design has dramatically contributed to life cycle cost savings in the transfer of hazardous wastes.
http://wxemd.com/about.shtml

[brian eiland]

To be installed on the new Panamax (http://www.superyachttimes.com/editorial/8/article/id/516Panamax) 'super-ketch'

"It’s not the only movable appendage below the waterline. Like an increasing number of new yachts, the Panamax ketch will take advantage of the advances in diesel electric power generation , in this case designed by MR Fertigung-Technologie GmbH, a German company based in Rostock. This allows the use of two retractable, electrically driven propellers developed by the award-winning Dutch company Van der Velden. By swinging or retracting the props into the hull the yacht's underbody will become perfectly flush when sailing, further enhancing -performance

Instead of using a conventional engine for propulsion, the Panamax will befitted with a number of generating sets (the likelihood is four) which, as Erik Wassen put it: “Will provide a power sharing opportunity with a priority system.”

In other words the generating sets will automatically deliver power to the numerous systems precisely when they want it and at sufficient levels, whether it be the hydraulic pumps for the big winch packages, domestic power to run the hotel systems or power for propulsion. Heavy battery banks are limited to emergency sets.

The generating system can devote all its energy to the retractable hubless props—the blades of the propellers are set on the inner surface of the circular units, which house the electric motors themselves instead of on a central hub."

...more
http://www.ybw.com/yw/blog/20070028174123blog_david_glenn.html

http://www.balticyachts.fi/documents/Pressrelease.pdf

[masalai]

When will a 10kw size be available for yachts, An electrically powered pair would be neat mounted on a swing up arm for my cat... particularly if capable of 'regen' use too - needs to be at a reasonable/competitive price - to 'partially' compete with the standard diesel drive systems.

I do not think I will be holding my breath waiting in anticipation...

[Guillermo]

Ron Holland designed Royal Huisman's "Ethereal", scheduled for delivery this year, has been equipped with two Van der Velden's 132 kW EPS 800. It is the first installation of its kind.

http://www.vdvelden.nl/rudders.cfm?pk=520&lang=en

Cheers.

[brian eiland]

RIM DRIVEN THRUSTERS
The development project of Rim Driven Thrusters continues. Design, production and testing of our prototype of 100 kW since 2003, has brought us
invaluable experience to use as we go further with our development. We also completed additional tests on this prototype in 2006.

The first of our larger units is scheduled to be delivered in 2007 for an offshore support vessel. This is an 810 kW tunnel thruster and is quite a departure from the first prototype.

To supplement experimental data for this type of design, adcanced design tools are applied. One of these is Computational Fluid Dynamics (CFD). This is a tool with direct integration with our 3D CAD/CAE tools and the flow calculations can include viscosity effects, turbulent flow and cavitation.

[brian eiland]

The Sea Jet Advanced Electric Ship Demonstrator (AESD), funded by the Office of Naval Research (ONR), is a 133-foot vessel located at the Naval Surface Warfare Center Carderock Division, Acoustic Research Detachment in Bayview, Idaho. Sea Jet - built by Dakota Creek Industries in Anacortes, Wash. - operates on Lake Pend Oreille, where it is used for test and demonstration of various technologies. Among the first technologies tested was an underwater discharge waterjet from Rolls-Royce Naval Marine, Inc., called AWJ-21, a propulsion concept with the goals of providing increased propulsive effiency, reduced acoustic signature, and improved maneuverability over previous Destroyer Class combatants.

In a program of research and development which was years in the making, Office of Naval Research (ONR), Rolls Royce Naval Marine Inc. (RRNMI), and the Signatures Department (Code 70) prepared the demonstration of an advanced waterjet-based propulsion concept, named AWJ-21. RRNMI, Walpole, MA, has developed the AWJ-21 propulsor concept with the goals of providing increased propulsive efficiency, reduced acoustic signature, and improved maneuverability over DDG 51 Class combatants. For this demonstration, a 130-foot-long craft designated the Advanced Electric Ship Demonstrator (AESD) was built. The AESD is being funded by ONR to demonstrate advanced electric ship and propulsor technologies. The ground-breaking demonstration is sponsored by the Office of Naval Research. Additional benefits from the AWJ-21 technology are expected to provide more compact propulsion systems with reduced weight and volume.

The AESD is an approximate quarter-scale destroyer class combatant with a length of more than 133 feet and a full load displacement of 120 tons [239,000 pounds]. The AESD hull form is based on the 5565 tumble-home hull tested early in the DD(X) program. As a result of availability of the AESD demonstrator craft, planning is underway to conduct other technology demonstrations. One such effort is the design of a low signature deckhouse for the model.


On 30 November 2005 the Advanced Electric Ship Demonstrator (AESD), Sea Jet, tied-up to the pier after completing its first day of sea trials on Lake Pend Oreille at the Naval Surface Warfare Center Carderock Division, Acoustic Research Detachment in Bayview, Idaho. The ship would test Rolls-Royce patented AWJ-21™ waterjet technology over the following six months on Lake Pend Oreille at the Navy’s Acoustic Research Department in Bayview, Idaho. The AWJ-21 is designed to increase ship speed, making hulls sleeker by working without rudders, shafts and propeller struts. Unlike conventional waterjets, the system works completely underwater, reducing noise and surface wake and improving stealth. The lightweight and compact AWJ-21 allows ships to operate in shallow waters. Its integrated steering and reversing system improves maneuvrability at low speeds.

Carderock Division’s Acoustic Research Detachment in Bayview, ID, is where most of the testing commenced in FY 05. Members of Philadelphia’s Code 90 supported machinery and electric drive quieting for the AESD. General Dynamics Electric Boat division similarly applied its expertise to the electric drive propulsion system. ARL at Penn State provided test support for the early waterjet development, and MIT assisted with the waterjet pump design. Computer Sciences Corporation (CSC) is responsible for the overall AESD boat design.

The RIMJET is a novel type of podded propulsion system that relies on a permanent magnet motor to drive the propeller, making it similar to the systems featured in this issue of Solutions (p32). In the RIMJET propulsor the motor is mounted not in the hub but in the rim, which GD Electric Boat believes provides a number of advantages. One of these is that because the RIMJET makes use of the same hydrodynamic principles as a waterjet, its applicability to high-speed vessels is much greater than conventional propulsors. Advantages over waterjets include high rotor torque capacity, rim attachment of rotor blades, minimal hull contour impact and azimuthing capability. The RIMJET’s high efficiency derives from its use of a phenomenon known as swirl recovery. Moreover, because it operates at a relatively low rpm, blade area is reduced, there is minimal duct and strut surface area, and the propulsor has low duct and strut velocities compared to hub-driven propulsors. The RIMJET has excellent cavitation performance because it operates at low rpm, it has very uniform inflow to the rotor, and the rim prevents the formation of tip vortexes. General Dynamics believes the RIMJET will also have better ‘off-design’ performance characteristics because the duct provides uniform mass-flow at off-design conditions.

It also promises to be much more reliable and maintainable than hub-driven pods. GD Electric Boat says the ‘canned’ permanent magnet motor at the heart of the RDP and stator are both sea-water cooled, eliminating the need for a cooling system and anti-condensation heating system. Having a seawater-lubricated journal and thrust bearings removes the need for a bearing lubrication system and seals, and having the strut outside the propeller wake reduces cavitation erosion. The duct also shrouds the ship’s hull from blade-induced pressure fluctuations.

[brian eiland]

This is Ethereal, a Ron Holland-designed 190ft ketch just launched from Royal Huisman in The Netherlands for Americans Bill and Shannon Joy. Just another superyacht, you may say, but this yacht's hybrid power system represents something very different and this unusual picture of her seemingly gliding across a 'sea' of green is significant.

She is seen here manoeuvring along the Dutch canal system en route to the open sea for trials where her she was put through her paces at 10 knots under power with no internal combustion engine in use. Instead she was using her lithium battery bank of 400kWh, designed to keep her running for a day with most of her onboard systems in use too. These batteries drive a Combimac electric motor/generator which rotates the shafts and then charges the battery bank when the yacht's more conventional twin Caterpillar 533kW diesels are brought into play.

She also has two 177hp electric Van der Velden hubless thrusters which can turn the yacht through 360 degrees in just 1min 40sec, not bad for a yacht weighing almost 500 tons!

According to Mike Koppstein of Huisman, who we talked to at the Fort Lauderdale Boat Show yesterday, the silent running mode is quite unnerving with no engine noise or vibration while 'motoring' with electric power. The same goes for the hubless electric thrusters.

Ethereal is currently undergoing sea trials in the North Sea and we hope to bring you a more detailed report in the pages of Yachting World in an upcoming issue.

[kistinie]

About small sized thrusters, for small boats, this below seems to belong to the same family ?
IntegratedThruster is a trademark of the University of Southampton. Products developed under licence by TLS.

http://www.tsltechnology.com/marine/thrusters.htm

[brian eiland]

It appears as though some of this development work on both the trusters and the propulsion units has stalled out along with the world's current economy.

I went looking today for some updates, and here are a few items I found along the way:
http://www.eee.manchester.ac.uk/pdf/research/pgr_conference/PTuohy.pdf

http://www.ship-technology.com/projects/olympic-octopus/

http://publishing.yudu.com/Ab9xx/WTMay08/resources/5.htm


http://www.riam.kyushu-u.ac.jp/ship/ittc/presentation/PPT-Propulsion.pdf (http://www.riam.kyushu-u.ac.jp/ship/ittc/presentation/PPT-Propulsion.pdf)

http://ammtiac.alionscience.com/pdf/WQV9N1_ART04.pdf

http://www.globalsecurity.org/military/systems/ship/dd-x-sea-jet.htm

[Tackwise]

As I am interested in the development of this new technology, I also try to follow any news on the subject. As far as I have gathered the following companies are busy with it:

Brunvoll: Rim Driven Thruster (RDT)
Power range & diameter: 200-900 kW & 800-1750 mm
Bowthruster: Allready installed some on one or more supplier ships
Main propulsion unit: They were going to install their first RDT as main propulsion unit on a Norwegian ferry. This ferry was scheduled to be delivered this month (august 2010).
The bow thruster version has been put on the market, however they are reluctant with their propulsion unit (no drive time experience) Hopefully this will change with the ferry!

van der Velden: EPS thruster
Power range & diameter: 90-295 kW & 650-1050 mm
Bowthruster: Installed on several yachts
Main propulsion unit: Under development
Rumour has it they have run into some problems with their unit.

Voith: Inline thruster/propulsion (VIT/VIP)
Power range & diameter: 5.5-300 kW & 240 -850 mm
Seems that they are in the progress of upgrading their range to include higher power and diameters!
Bowthruster (VIT): Several tugs
Main propulsion unit (VIP): Amsterdam canal boat (with fuel Cell technology)

Rolls Royce:
Power range & diameter: ~850 kW & ???
Bowthruster: Installed on one or more Supplier ships
Main propulsion unit: unknown
Still in development stages therefore not fit for marketing (in otherwords their sales department do not get informed on the possibilities)

TSL technology
Power range & diameter: ??? & 50-300mm
Bowthruster:
Main propulsion unit: application on ROV's

Klingenburg: Prop-eye
Fleetwater marine: Ring driven thruster
G-tec: ring prop
Schilling: (ring thruster) (ROV)

[brian eiland]

Thank you Tackwise for that summary/update.
Brian

[M. Himes]

Has Rolls-Royce computed the advantages of coaxial high by pass (Coanda Effect) flows? A magnetohydrodynamic axial vortex flow aguments the central rim thruster flow to both increase volume and flow rate of the thruster. Given this combined flow electric thruster for submarine propulsion seems to provide low acoustic signature and very low power consumption.

[brian eiland]

The M/F Eiksund, a RoRo car and passenger ferry of LOA 160 ft (49 m), beam 34.7 ft (10.6 m) and draft 10.2 ft (3.1 m) was built in 1970 and originally powered by a single Wichman 552 kW (750 hp) diesel engine with mechanical drive to two propellers.

She has been repowered with a new propulsion system consisting of two new diesel engines driving Permanent Magnet (PM) generators and two Brunvoll RDT1500 azimuth RDT which is the world’s first commercial application of this type of drive. Control and management of the generators and propulsion system is provided by Inpower, Norway.

http://articles.maritimepropulsion.com/article/First-ship-with-Azimuth-Rim-Driven-Thrusters-enters-commercial-service-5669.aspx (http://articles.maritimepropulsion.com/article/First-ship-with-Azimuth-Rim-Driven-Thrusters-enters-commercial-service-5669.aspx)

[brian eiland]

Passenger Vessels and Yachts to Use Voith Thrusters (http://www.offshorewind.biz/2011/11/17/passenger-vessels-and-yachts-to-use-voith-thrusters-germany/)

Voith currently is the only manufacturer world-wide to produce thrusters with a power of 1 500 kW based on permanent magnet synchronous machine technology (RIM drives). Recent orders for offshore applications, passenger vessels and yachts underline Voith’s position as global market leader for these systems.