It might not sound very spectacular, but the advantages can be significant.  In large cruise liners, electric motors drive propellers directly for smother running.  There is no direct mechanical connection.  Tugs and research ships have been using drives without mechanical switching units for some time, on account of their manoeuvrability, and high efficiency, in partial load range. Many naval boots have electrical cruising motors, which must run extremely quietly.



Article in "Yacht" on 21.04.04 - Innovation: The perfect alternative to a ship diesel


PANDA diesel-electric boat


Test Boat


The Icemaster test yacht, 35 foot Motor sail boat, carries the E-Motor in a type of pod under the hull. It can rotate 180 degrees. The Permanent Magnet Machine is a brushless DC motor. An Electronic Control produces the otherwise normal pole winding. It not only runs without wear, but is, above all more effective.

In order to achieve a drive performance of 12 Kilowatt with low current, the motor is driven by up to 480 Volts, generated by a 14-Kilowatt- Fischer Panda generator. It has little to do with generation of power, apart from the principle, how they can be made available for 230-Volt-devices. These would simply be too inflexible for ship propulsion. True, the Fischer-Panda-Generator also internally generates AC, but optimized for powering DC circuits. The speed of the diesel motor is infinitely adjusted to match the required drive performance.
AC Generators, on the other hand, run at constant speed, in order to generate a frequency of 50HZ. This means, they run at 3000 rpm without load. Conventional ship diesels are similarly inefficient. They are so designed that at full speed, the nominal speed and also the highest performance is achieved. More torque is available in the partial load range, than can be produced by the screw in the water.

This is exactly where the great energy saving potential of the Fischer Panda concept can be found: In the case of electrical power transmission, the speed of the propeller and ship diesel are extensively disconnected. The Generator can always run economically in this range.

The „Aziprop". This is the name of the test yacht, consumes less than half the fuel during cruising, since modification has been carried out, in comparison to the previously installed 38PS diesel. And: There is indeed more power available during manoeuvring, because of the torque characteristic, which is more suitable for ship propulsion.

In addition, highly powerful AC power supply. On board, 230 volt devices can easily be run by the DC system via an inverter. Smaller consumers, such as hair dryers or laptops are powered by the batteries. The diesel generator automatically starts, as soon as the rechargeable batteries lose power. Up to 4 Kilowatt is then available – more than enough, even for an air conditioning unit.



Generator diesel-electric installation




Only in the case of sailing yachts was this comfortable and economical technology not used as being too heavy and too expensive.  The generator manufacturer, „Icemaster“, better known as „Fischer Panda“ have been working for five years to find a suitable solution for small boats.  The „YACHT“magazine have, for the first time, published the results of a boat with a fully tested diesel electric drive.

The Principle is simple: A normal diesel motor is driven by a large generator. This unit, known in expert circles, as genset is fully contained in a capsule and supplies power to the electrical cruise motor. The reverse gear functions and gear reduction are electronically controlled.

Until a few years ago, the price and effort required for the necessary components bore no relation to the achieve-able advantages, at least, for the normal drive performance of yachts. The use of the most modern technology means the concept is now ripe for this system to be also installed into sport boats. Icemaster use brushless DC motors and an innovative electronic control. This improves the system enormously. The cruising motor and generator, for example, are almost identical, which reduces the development and manufacturing costs. This should not be mistaken for purely electrical driven boat drives, which are nowadays, in general use. The battery bank is used as a buffer. The range, using batteries, for long sailing trips along the coast or at sea, is, however, to small; that is why this concept is suitable, fore-mostly for inland waters. The diesel electric drive, on the other hand, generates the cruising current, whenever it is required, and the range is superior to conventional ships.


Azimuting podded propulsion systems have already been approved in the big ship building industry for several years.Shortly after its introduction, the system became the standard solution. Many newly designed oceangoing passanger cruising vessels built later after 1999 have this outstanding new propusion system fitted. The motors are avalable up to 20.000 kW performance per unit with up to 3 units mounted underneath the hull.



Cruise ship installation



The lack of noise is impressive whilst cruising at 6 Knots: gulls crying, the bow wave splashes quietly and somewhere in the fjord, a freight ship can be heard chugging along. The motor and generator run in sound insulated capsules below deck. Practically only the cooling water discharge can be heard. This is no comparison to the racket made by some ships` diesels.

There are two reasons for the unusual peace; firstly there are no sound or vibration jumpers at the hull. All mountings are cushioned – there is no mechanical connection between motor and prop, such as shaft or sail drive. Secondly, the diesel electric drive is doubly insulated, because the installed diesel and generator unit, located in the engine room, are additionally in a capsule.

Disconnection of the motor and propeller has further advantages. The generator can be placed where it will not take up too much space. In addition, it is easy top lay the cables to the E-Motor. On catamarans, a central “power plant” suffices for both drives.

The costs for a diesel electric drive are, true, somewhat greater than the classic diesel. The generator is supplied as well. Reason enough to consider this convincing concept.  Icemaster are already working on the next project. A series Volvo Penta Diesel Bavaria 49 is being converted to electrical power transmission.

180 degree turning - no need for bow thruster

Aziprop is the registered trade mark of Fischer Panda. Fischer Panda has developed the System based on the AGT Permanent Magnet Motor Technology.  These electric motors are based on the latest technology.  Fischer Panda has been involved with this technology for more than 10 years.  The Panda DE Aziprop system combines both electric motor and propeller into one unit. The motor is located underneath the hull, in a rotatable gondel (a fully sealed stainless steel housing.)



Further Information regarding Bavaria 49DE and Whisper prop can be found on the following Links: 

Fischer Panda Generatoren ICEMASTER GmbH   -    Otto-Hahn-Str. 40 D-33104 Paderborn - Germany
Tel.+49 (0)5254 - 92020    Fax.+49 (0)5254 - 85724



This website is Copyright © 1999 & 2005  NJK.   The bird logo and name Solar Navigator are trademarks. All rights reserved.  All other trademarks are hereby acknowledged.       Max Energy Limited is an environmental educational charity.