Product

THE ECO FLETTNER Rotor WITH TWO END DISKS REPRESENTS THE LATEST GENERATION OF A WIND ASSISTED PROPULSION SYSTEM (WAPS)

It’s a redesign of the Flettner concept which takes advantage of the so-called Magnus effect in the presence of side wind to produce additional thrust forward. The EF rotor in different sizes rotates around a pivot with upper and lower bearings. It has many innovative design features, such as lightweight materials and the ability to rotate at high speeds. The use of two end disks ensures very favourable flow conditions around the rotor.

The rotors acts additively to the propeller and with increasing sailing performance the main engine power is to be reduced efficiently. It is full functional and independent propulsion system. The crew can choose to utilize the extra thrust generated by the rotor to reduce engine power and fuel consumption, or to increase the ship’s speed.

annika braren ship with rotor at harbour

ECO FLETTNER ROTOR
18 M HEIGHT & 3 M DIAMETER

Technical Specifications

Sail surface (m²)	54
Diameter of upper and lower end disks [m]	6
Material	Rotor: GFP Mast: Steel
Rotor Speed (rpm)	Max. 280
Lightning conductor / Ice prevention	yes / yes
Support structure
Tower	Steel
Foundation height (typical) [m]	Hight between main deck and forecastle deck + 2300 mm over forecastle deck = approx. 5000 mm ⌀= approx. 2300 mm
Weight incl. typical foundation [tons]	Approx. 34 t / ship specific
Drive	Electric geared motor
Electric power (kW)	75
Variable speed drive	yes
Brake resistor / Mechanical lock	Electric Brake / yes
Control system software	yes
Hardware	yes
Condition Monitoring System	yes
Thrust Measurement System	yes
ATEX compliant design	on demand
Ambient conditions
ATEX compliant design	on demand
Operational temperature	40° C ambient temperature in the tower
Operational wind speed range	TADC (DNV GL) 30 m/s
Survival wind speed	TADC (DNV GL) 50 m/s
Thrust	Approx. 78 kN / BN9 (22,5 m/s)
Lead time (month)	12
Life Time (h)	Approx. 50.000 h in full load condition

ECO FLETTNER ROTOR
24 m height & 4 m diameter

Technical Specifications

Sail surface (m²)	96
Diameter of upper and lower end disks [m]	8
Material	Rotor: GFP Mast: Steel
Rotor Speed (rpm)	Max. 210
Lightning conductor / Ice prevention	yes / yes
Support structure
Tower	Steel
Foundation height (typical) [m]	Hight between main deck and forecastle deck + 2300 mm over forecastle deck = approx. 5000 mm ⌀= approx. 3300 mm
Weight incl. typical foundation [tons]	Approx. 43 t / ship specific
Drive	Electric geared motor
Electric power (kW)	135
Variable speed drive	yes
Brake resistor / Mechanical lock	Electric Brake / yes
Control system software	yes
Hardware	yes
Condition Monitoring System	yes
Thrust Measurement System	yes
ATEX compliant design	on demand
Ambient conditions
ATEX compliant design	on demand
Operational temperature	40° C ambient temperature in the tower
Operational wind speed range	TADC (DNV GL) 30 m/s
Survival wind speed	TADC (DNV GL) 50 m/s
Thrust	Approx. 139 kN / BN9 (22,5 m/s)
Lead time (month)	12
Life Time (h)	Approx. 50.000 h in full load condition
AT THE PLANNING STAGE

ECO FLETTNER ROTOR
31 m height & 5 m diameter

Technical Specifications

Sail surface (m²)	155
Diameter of upper and lower end disks [m]	10
Material	Rotor: GFP Mast: Steel
Rotor Speed (rpm)	Max. 165
Lightning conductor / Ice prevention	yes / yes
Support structure
Tower	Steel
Foundation height (typical) [m]	Hight between main deck and forecastle deck + 2300 mm over forecastle deck = approx. 5000 mm ⌀= approx. 4300 mm
Weight incl. typical foundation [tons]	Approx. 53 t / ship specific
Drive	Electric geared motor
Electric power (kW)	230
Variable speed drive	yes
Brake resistor / Mechanical lock	Electric Brake / yes
Control system software	yes
Hardware	yes
Condition Monitoring System	yes
Thrust Measurement System	yes
ATEX compliant design	on demand
Ambient conditions
ATEX compliant design	on demand
Operational temperature	40° C ambient temperature in the tower
Operational wind speed range	TADC (DNV GL) 30 m/s
Survival wind speed	TADC (DNV GL) 50 m/s
Thrust	Approx. 247 kN / BN9 (22,5 m/s)
Lead time (month)	12
Life Time (h)	Approx. 50.000 h in full load condition
AT THE PLANNING STAGE

Since 01/01/2021 NaMKü-

This German funding is appropriate for installation of wind assisted ship propulsion systems (WASP) for retrofits and new buildings:

Förderrichtlinie „Nachhaltige Modernisierung von Küstenschiffen“

Funding guideline "Sustainable modernization of coastal ships"

Download:
For more information please click here: NaMKü

Advantages
OF THE ECO FLETTNER rotor SAILING SYSTEM:

NO ADDITIONAL CREW REQUIRED ON BOARD

No set, trim or reef of sails

NO SAFETY RISKS IN SEVERE WEATHER

heavy weather sailing system

NO IMPACT IN THE CARGO OPERATIONS

An easy-to-use operating system is combined with intelligent voyage optimization programs

Fully automated and intelligent sailing system

Less CO₂, SO_x, NO_x and other emissions

IMO – Improved energy Efficiency of ships (EEDI+EEXI)

Charterer/Shipper benefit from improved carbon footprint on supply chain

Higher charter rate achievable due to fuel savings

Efficiency

The ECO FLETTNER technology achieves with a new generation of rotor sailing systems for the break-through as a building block for low-emission shipping

The main question about modern rotor sailing systems is about the performance potential and fuel savings. For the prediction of the rotor’s propulsion power and associated fuel savings, numerous model tests and simulations were performed using the wind tunnel of TU Hamburg-Harburg and numerical CFD methods at the Center for Modelling and Simulation at the Emden/Leer University of Applied Sciences. Transparent performance data is required to enable an economic prognosis for the use of Flettner rotors on ships.

The expected performance figures are based on the test trails on MV Fehn Pollux (2018).

In medium wind areas

(e.g. Mediterranean Sea)
2 kW main engine equivalent power per 1 qm of rotor surface
e.g. MV Fehn Pollux 108 kW
about 16.6 % at 650 kW (MCR) Maximum Continuous Rating

In good wind areas

(e.g. North Sea and Baltic Sea)
performance expectations
2,5 kW main engine equivalent power per 1 qm of rotor surface
e.g. MV Fehn Pollux 135 kW
about 20.8 % at 650 kW (MCR)

In very good wind areas

(e.g. Atlantic Ocean)
performance expectations
> 3 kW main engine equivalent power per 1 qm of rotor surface
e.g. MV Fehn Pollux > 162 kW
about > 24.9 % at 650 kW MCR

The savings potential depends on the wind conditions along the route and other factors. Precise predictions are made by route simulations for a specific ship.

THE ECO FLETTNER ROTOR

In medium wind conditions the rotor sailing system produces 2 kW propulsion power per square meter. The amount of achievable savings depends on where the ship is in operation and the projected area.

For example: The EF18 rotor has a sail area (H × D) of 54 m². Multiplied with 2 kW per square meter the EF18 produces 108 kW main engine equivalent power in annual average in a medium wind area and 162 kW (>3 kW) in very good wind areas. With this formula ship owners can calculate size and quantity of rotor sails, which are necessary to get a specific amount of fuel and emission savings.

POWER OF ROTOR AND MAIN ENGINE IN RELATION TO SHIPS SPEED
(MV FEHN POLLUX)

Data collection and data evaluation by the University of Applied Sciences Emden/Leer, Germany, Prof. Capt. Michael Vahs, published in Schiff & Hafen Heft 2/2019, Germany

The rotor was used to increase the ship’s speed and compared with the equivalent power required for the main engine to achieve the same speed increase.

In normal charter service of MV Fehn Pollux, the main engine power is limited to about 650 kW (Eco-Speed). On MV Fehn Pollux average fuel savings in the range of 15–20% can be expected depending on the required ship speed and the sailing area.

Performance figures for the EF18 rotor under optimal wind conditions:

Rotor thrust approximately 80 kN
Rotor propulsion power about 700 kW equivalent to the main engine
A temporary 100% sailing mode

Yearly fuel and emission savings in automatic modus:

More than 130 t of Marine Gas Oil, this means a reduction of about 400 t of CO₂, 3.3 t less SOX, 4.6 t less NOX and 0.4 t less particle emissions
ECO FLETTNER rotor sailing systems will get contribution to the energy efficiency requirements (EEDI + EEXI) for new buildings and existing ships.

Integration

For flexible implementation
in the hull
4,500 tdw MPC (Mini Bulker)
with 18 m Rotor
11,000 tdw MPC with 24 m Rotor

training

A thrust measuring system, a rotor control system and a crew training system are genuine innovations, which have been designed and developed by partners of the ECO FLETTNER project. A three-days crew training with the main focus on manoeuvring a rotor vessel has been implemented at the ship handling simulator of the company Nautitec in Leer. On request we offer a three-days training course.