L-1011 Engine: Rotating Assemblies

The RB.211 engines used on the Lockheed L-1011 have three rotating assemblies rather than two. Many more stages would be necessary to get the same compressions ratio which would create a very long engine. The 3 spooled design results in a short rigid engine which has less parts.

Compressors are referenced as a Low Pressure (LP), Intermediate  Pressure (IP) and High Pressure (HP).

The HP compressor drives accessories through a step aside gear box. Accessories are mounted on the LH and LP compressor case.