Exciting New EPS Thruster (& Propulsion)

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?

 

Rolls-Royce unit

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."

 

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

 

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

 

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/2003/7000/7720emerson.html

 

EPS Thruster & Propulser

...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)

 

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/......

 

Design of a 100kW Permanent Magnet Thruster

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

 

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

 

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.

 

Thrust

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, 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!

 

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.

 

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

 

A Retraction Scheme

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

 

Tidal Flow Rim Drive Generator

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