This article deals with the unique solutions developed for the Hammerfest liquified natural gas project. A liquefied natural gas (LNG) production unit has been equipped with all-electric, variable-speed refrigeration compressor drivers with the ratings of 32 and 65 mW. These compressor strings have been successfully tested by load performance, and their actual service was commenced in autumn 2007. This article focuses on the rotordynamic aspects of the high speed brushless synchronous motors. LNG production involves gaseous methane liquefaction in an extensive refrigeration process. FE calculations of the system is performed to avoid vibration problem at site.