C4iSR: Maritime

Siemens unveils new FLEX PM modular submarine propulsion motors

20 May 2019

Siemens premiered its new generation of modular scalable permanent magnet submarine propulsion motors at the Underwater Defence Technology (UDT) 2019 exhibition in Stockholm.

To provide solutions across a wider range of applications, Siemens is evolving its Permasyn permanent magnet compact submarine propulsion motor.Cut-away model of Siemens' current Permasyn permanent magnet motor for submarine applications. (IHS Markit/Alex Pape)Cut-away model of Siemens' current Permasyn permanent magnet motor for submarine applications. (IHS Markit/Alex Pape)

The current Permasyn offering is available with ratings of approximately 2 MW and 4 MW, and has to date been used on Thyssenkrupp Marine Systems’ Type 212A and Type 214 submarine designs, with the first motor delivered for installation in 2000.

Several years ago, the company sought to develop a new, larger motor in the 6 MW class. The new flexible Permasyn (FLEX PM) modular solution, however, aims to cover a range from 1.5 MW to 8 MW.

The new motors are planned in three baseline frame sizes, with the diameter determining three power ranges. The specific power rating within one range is then fine-tuned with the length of the stator and rotor. The ultimate size and weight are also driven by the associated inverters, which are integrated in the motor itself.

According to Siemens, the specifications for this drive concept have been completed and initial development work has commenced.

With the new FLEX PM development, Siemens is also expecting improvements in reducing acoustic and magnetic signatures.

Want to read more? For analysis on this article and access to all our insight content, please enquire about our subscription options at

(234 of 325 words)


  • Mk 20 Electro-Optical Sensor System (EOSS)

    Type Naval Fire-Control System (FCS). Development In 2005, following a competitive procurement process, Kollmorgen Electro-Optical (acquired by L-3 Communications in February 2012 and now operating as L-3 KEO) was chosen to provide the US Navy (USN) with an EOSS as part of the CG-47