Update on solution to RN gas turbine sea water lubricating oil cooler failures when caused by Sulphate Reducing Bacteria ('SRB')

摘要

A managed programme to review engine failures and take necessary preventative measures has been in place successfully in the Royal Navy since the introduction of gas turbines into service in the 1970's. One of the more prominent failure mechanisms with the Tyne RM1C and Spey SM1A engines has been the degradation of main line bearings accounting for 25 percent of all engines rejected. Historically, since the first recorded incident in March 1987, the failures pointed to poor performance of the bearings themselves. However, maintenance studies and recent analysis indicates that a vast proportion have occurred through previously unidentified chloride corrosion as a result of contamination of the lubricating oil system with salt water from the seawater lubricating oil cooler (SWLO cooler). Despite joint ownership of both engine variants with the Royal Netherlands Navy, there was no clear evidence until about six years ago to suggest why tube perforation was occurring. Indeed, the fact that failures have only occurred in Royal Navy service is an interesting twist to the problem.