Design of Mainline Bearing Systems for Conway Turbofan Engines: A Description of the Hoffmann Roller Bearings Used to Support Low Pressure and High Pressure Turbine‐Compressor Assemblies on the Rolls‐Royce Conway R.Co.12 and R.Co.42

THE Rolls‐Royce Conway 12 and Conway 42 are equipped with similar mainline bearing systems. The Conway 12 has a thrust rating of 17,500 lb. and is fitted in the Boeing 707 and Douglas DC‐8 airliners. A total of over three million operational hours has been accumulated by engines of this type, and individual bearings fitted to individual engines have been in service for more than 9,000 hours.