Azipod is the ABB Group's registered brand name for their azimuth thruster. Originally developed in Finland jointly by Kvaerner Masa-Yards dockyards and ABB, these are marine propulsion units consisting of diesel-electric-driven propellers mounted on a steerable pod.
The distinguishing feature between the Azipod class of propulsion and other azimuthing propulsion devices is that in the Azipod all propulsion power is delivered by an integrated electric motor instead of a mechanical shaft to the vessel and a gearbox. The mechanical system has a long tradition throughout the 1900s, and applications based on it are widely produced today. Also see the articles Z-drive and L-drive.
As of April 2012, 230 Azipod units had been installed on over 100 vessels in both single and multiple unit installations, with over 7 million hours of overall service. 
One of the competing products of similar type is the Rolls-Royce Mermaid azimuth thruster,  which can be found on some passenger ships such as the Queen Mary 2. Most of the world's production of azimuthing propulsion systems is currently located in Finland, with Rolls-Royce's factories being located in Rauma and ABB's in Helsinki.
The pod's propeller usually faces forward because in this puller (or tractor) configuration the propeller is more efficient due to operation in undisturbed flow. Because it can rotate around its mount axis, the pod can apply its thrust in any direction. Azimuth thrusters allow ships to be more maneuverable and enable them to travel backward nearly as efficiently as they can travel forward.
The podded design typically achieved a 9% better fuel efficiency than the conventional propulsion system when it was first installed in the 1990s. Improvements to the conventional design have shrunk the gap to 6%-8%, but on the other hand the hydrodynamic flow around the Azipod has been improved by fin retrofits and a dynamic computer optimization of the respective operating angles of the pods in multipod installations, yielding overall efficiency improvements now in the range of 18%.
In the traditional azimuth propulsion system, the motor is inside the ship's hull and the propeller is driven through shafts and gearboxes. In the Azipod system, the electric motor is inside the pod, and the propeller is connected directly to the motor shaft. The AC motor of the pod is driven by electricity from the ship's generator by a cycloconverter. By avoiding the use of a traditional propeller shaft, the propeller can be further below the stern of the ship in a clear flow of water, thereby providing greater hydrodynamic and mechanical efficiency.
Electric power for the Azipod motor is conducted through slip rings that let the Azipod rotate through 360 degrees. Because fixed pitch propellers are used in Azipod units, power for an Azipod system is always fed through a variable-frequency drive or cycloconverter that allows speed and direction control of the propulsion motors.
|This section requires expansion. (October 2013)|
In 1987, the Finnish National Board of Navigation made a co-operation proposal to the multinational electrical equipment corporation ABB Group and the Finnish shipbuilder Masa-Yards for the development of a new type of electric propulsion unit. Prior to this, the companies had been working together for decades in the field of diesel-electric propulsion systems and in the 1980s produced the first icebreakers with alternating current propulsion motors and cycloconverters.
The development of the prototype started in 1989 and the first unit was ready for installation in the following year. The 1.5 MW unit, dubbed "Azipod" (a portmanteau of "azimuth thruster" and "podded propulsion unit") was installed on the 1979-built Finnish fairway support vessel Seili. After the refit, the vessel's icebreaking performance was considerably increased and she was found out to be capable of breaking ice also in the astern direction. This eventually led to the development of the double acting ship concept in the early 1990s. When Seili was refitted with new propulsion system in the 2000s, the prototype unit was donated to Forum Marinum and put on display in Turku, Finland.
Following the encouraging experiences from the prototype installation, the development of the Azipod concept continued and the next units were retrofitted on two Finnish oil tankers, Uikku and Lunni, in 1993 and 1994, respectively. The result was again a considerable increase in the icegoing ability of the vessels that were already built with independent icebreaking capability in mind.
While the smaller Azipod C design (up to 4.5MW power) seems to have been a largely trouble-free design, during the initial years in service some widely publicised cruise ship service disruptions with the bigger Azipod V design have occurred, see e.g. After the 2000 incident with the Carnival Paradise, the root cause of the problems with the propeller shaft bearing was found and a modification programme was initiated for the fleet of Azipod Vs to take place during their scheduled drydocking, with very favourable results.
The latest design, the Azipod X, incorporates these improvements, with a view to a service interval of five years, and features bearings that can be taken apart and repaired from the inside of the pod while the ship is harboured normally. The latest major newbuilds featuring the Azipod XO are the two as yet unnamed 3,250 passenger vessels for the AIDA Cruises, the Celebrity Reflection (2012), the Norwegian Breakaway and the Norwegian Getaway.
- Tammiaho, Erkki. "Ruoripotkurilaitteiden liiketoiminta Suomessa (Propulsion units operations in Finland), TEKES, 258/2009" (PDF) (in Finnish, illustrated). Retrieved 2013-12-05.
- "ABB Oy, Marine & Cranes". ABB. 2013-05-22. Retrieved 2013-09-24.
- "Podded Propulsors". Rolls-royce.com. 2013-05-23. Retrieved 2013-09-24.
- "Azipod propulsion drives take the next step". Skipsrevyen. March 2011. Retrieved 2013-09-24.
- http://www.maritime-suppliers.com/imidocs/90580P007%20CRP%20Azipod.pdf[dead link]
- Pakaste, Risto et al. (February 1999). "Experience with Azipod propulsion systems on board marine vessels" (PDF). Retrieved 2012-12-25.
- Hepo-oja, Anssi; Mäki-Kuutti, Viktor (2012). Mekaanisen ja sähköisen propulsiojärjestelmän esittely. Satakunta University of Applied Sciences.
- Cycloconverters for the new icebreaker from Kymmene-Strömberg. Navigator 1985.
- 1. Dynamosta Azipodiin - vuosikymmenien kokemukset jäänmurtajista. ABB Group. Retrieved on 2013-10-05.
- Juurmaa, K et al.: The development of the new double acting ships for ice operation. Kvaerner Masa-Yards Arctic Technology, 2001 and 2002.
- Juurmaa, K et al.: New ice breaking tanker concept for the arctic (DAT). Kvaerner Masa-Yards Arctic Technology, 1995.
- Fredrickson, Tom (2000-07-22). "Carnival's Paradise Coming To Yard For Repairs". Newport News, Virginia: Daily Press. Retrieved 2013-09-24.
- "Carnival Corporation And Abb Reach Settlement On Azipod® Propulsion System". Carnival Corporation. Retrieved 2013-09-24.
- "Propulsion Systems by ABB Marine". Wplgroup.com. 2012-02-13. Retrieved 2013-09-24.
- "AIDA newbuilds will use air bubbles and Azipods to cut fuel consumption". MarineLog. 2012-03-12. Retrieved 2013-09-24.
- "Bearing Failure Sidelines Cruise Ship Again". The eBearing News. 2005-03-28. Retrieved 2013-09-24.
- "Rolls-Royce Crystal Settle Mermaid Propulsion System Row". Law360.com. Retrieved 2013-09-24.