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Since many years the advantages of pods are mainly used by bigger vessels
In a pod drive, the drive is covered with a gondola and is rotatably mounted to ensure a vertical rotation[ds_preview] of 360°. The propeller is attached as a drag-propeller at the front of the gondola, as thrust propeller at the rear of the gondola or in combinations of one or more free-range drag and thrust propellers. The gondola also holds the drive which is an electric motor.

This is the main contrast to thruster propellers where the drive is located in the hull and is connected with the propeller by mechanical drive shafts.

Pod drives are used primarily to larger units, for example on cruise ships. Good maneuverability is an advantage of this technique. Also, the option to rapidly reduce speed is among the positive features of these devices. Due to a relatively small diameter propeller pods can also be mounted at a relative distance from the outer shell of a ship’s hull. This causes less noise and vibration, an advantage which is especially appreciated aboard cruise ships.

According to Friedrich Wirz from the Technical University of Hamburg-Harburg (TUHH), however, difficulties of the past related to the bearing and sealing gasket of pods. For the future, Wirz estimates pod development will be especially in the field of mechanical engineering. Currently, there are considerations to change the bearings of the pod. Right now anti-friction bearings are used, says Wirz. However, there are expert considerations for change towards hydrodynamically lubricated plain bearings. One goal defined for the future is thus to reduce the housing size. Another challenge relates to the cooling of the gondola, the expert says. Wirz also envisages further potential in terms of electric engines. Efficiency improvements are on the recent agenda. Regarding the performance of the pod drives Wirz assumes this »will continue to be closely linked to ship size development.«

ABB has launched a new Azipod development on the market. The so-called »Azipod D« complements the Azipod product family already operational aboard cruise ships, icebreakers, ice-going cargo ships and offshore units.

The innovation is now also intended for offshore oil rigs, construction vessels, support vessels and ferries, ABB announced. According to the manufacturer the Azipod-D model increases flexibility, reliability and energy efficiency. The electric drive enables shipowners and operators to increase the profitability of their ships through low maintenance costs and reduced fuel consumption. Further advantages are defined by improved maneuverability and in maintenance and serviceability as well as improved power efficiency compared to mechanical drives, says the manufacturer. Thus the »Azipod D« needs up to 25% less installed power, because the power of the electric engine can be increased by up to 45% just by the new hybrid cooling system. The driving performance of the new pod covers a range of 1.6 to 7 MW per unit.

The following market overview presents products from different suppliers.


TWG