Exciting New EPS Thruster (& Propulsion) - Boat Design Net

Jun. 09, 2025

Exciting New EPS Thruster (& Propulsion) - Boat Design Net

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 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 !!

Peripheral Journal Propeller Drive

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,
PERIPHERAL JOURNAL PROPELLER DRIVE

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

Attached Files:

EPS (what does it stand for?)

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.

Rim Driven Propulsers

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 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.

Attached Files:

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/0/0F5A219AA75C9EC4CE22F7/$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 kW and total electric power staggers to a huge kW! Of these, 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.

Attached Files:

That's a very interesting document. 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'!

Rim Driven Thruster & Propulsor

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.

Attached Files:

AIR Fertigung unit

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.

Attached Files:

bearings

An 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."

Considering a bow thruster; best choices? - Trawler Forum

Somebody in our family recently suggested a bow thruster might make that somebody's job slightly easier while docking... so just in case a bow thruster project bubbles up to the top of my wallet anytime soon...

So without debating whether they're useful or not... without considering hydraulic thrusters or genset PTO options... and without considering external thrusters...

And assuming I'd probably prefer a 24V tunnel system with dedicated AGM batteries located very near the bow thruster, probably with a dedicated 24V own charger... in our 42' 28K-lbs boat...

I thought it might be useful to start with a "market survey" of sorts.

I've only superficially looked at options like the Imtra/Side-Power SE80 and the Vetus/Maxwell BOWD, without lots of time comparing thrusters to boat sizes/weights yet. I assume there might be decent options from Lewmar, Max Power, maybe others...

Who's got a thruster? Which one (brand/model)? In what boat?

Comments about horsepower vs. boat size? About single prop vs. dual prop? Good or bad about various brands or designs?

-Chris

Ok, I was looking at Imtra's site and saw a $1,300 difference on a $5,200 thruster. Figuring you would be looking at 5 figures all in, $1,300 wasn't significant.

Did you get an estimate on installing the tunnel?

In the grand scheme of things... you might well be right about what's significant.

Today is the first I've really thought of pursuing the whole idea... since it was just last evening I was informed it might be a good idea... so, no, haven't yet got anything more than hearsay about installation costs.

I'm guessing all in, thruster, assuming two Odyssey PC-s in series to 24V, a 24V charger, and some whiz-bang nifty controls, plus installation (including the tunnel)... maybe 2.5-3x the cost of just the thruster.

??

-Chris

In the grand scheme of things... you might well be right about what's significant.

Today is the first I've really thought of pursuing the whole idea... since it was just last evening I was informed it might be a good idea... so, no, haven't yet got anything more than hearsay about installation costs.

I'm guessing all in, thruster, assuming two Odyssey PC-s in series to 24V, a 24V charger, and some whiz-bang nifty controls, plus installation (including the tunnel)... maybe 2.5-3x the cost of just the thruster.

??

-Chris

Chris, I'm not an expert on bow thruster installations, nor have I ever played an installer on TV, however, this is what I know:

Installing the tube is not rocket science for a good fiberglass man. On a displacement hull boat, it's not that bad a job. Sean the guy who did the fiberglass and paint work on my refit has done one or two. I watched him do one and if you can figure out where the hole goes, the rest is fiberglass work.

With a planing hull there's more to putting the tube in. The placement is more critical and the eyebrow effect around the hole is important for hull performance when on plane. Simply, you want to make darn sure the installer has done a number of planing hulls including ones in your size.

While I'm just guessing from my armchair, a complete install from a bow thruster installer, soup to nuts, $15K. Hope it's less.

Ted

My take on thrusters is plan to dock like you don't have them and use them sparingly. This way you minimize battery capacity problems. Especially if you have twin engines. Use those engines and save the thruster until you really need the added sideways bump.

With a single engine or in more challenging docking conditions it'd be different. If you'd be fighting against a lot of tide, current or winds on a regular basis then larger battery capacity, 24v or going hydraulic, is definitely worth considering. But for around here on the Chesapeake conditions are usually mild enough to not have to get into extremes.

Yeah... but I'm not really debating whether I need a thruster or whether they're useful... or in what conditions. I've got enough experience with twins and a single to not really be bothered about all that...

At this point, it's just a question of "If I want a thruster, which do I get?" I've eliminated AC- or hydraulic-powered units as probably being more complex than I would want to fool with. Likely more expensive, too, but that's just a guess.

Then it also comes close to a question of a "Is 12V sufficient or is 24V (in a 12V boat) enough better to warrant the extra cost?"

Either way, I think I'll maybe need (or want) a new charger, maybe dedicated only to the thruster bank, and in that scenario... especially if a new charger could likely be co-located with the thruster bank and the thruster bank is colocated with the thruster... the difference between 12V and 24V may be a wash, cost-wise. I'm kind of debating this part with myself, as we speak.

We currently have an older 40-amp 12V charger dedicated to our port dual-purpose bank, and a 70-amp 12V inverter/charger dedicated to our starboard dual purpose bank.

Neither of those chargers is large enough to meet the two battery makers' recommendations for ideal minimum charging current... although they're "OK enough" at least for now. If the older 40-amp charger goes south, I'd likely replace it with a 60-amp unit, which may mean new wiring and still wouldn't meet recommendations for ideal minimum charging level for that bank.

Anyway, that kind of stuff is what's going through my mind just now...

High Wire makes an excellent point about being able to get service, in various places.

Which makes me ask if service possibilities on Side-Power, Vetus, or Max-Power units is roughly equal, or if one/some are much better than another?

-Chris

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Exciting New EPS Thruster (& Propulsion) - Boat Design Net