Complex sentence: The design of the Class 156 was more conservative than Metro Cammell's earlier Class 151 design, the bodyshell was made of steel instead of Aluminium, and the cab design was deliberately similar to the BREL Class 150 to ease union acceptance.
Split into simpler sentences: The design of the Class 156 was more conservative than Metro Cammell's earlier Class 151 design. The bodyshell was made of steel instead of aluminium, and the cab design was deliberately similar to the BREL Class 150 to ease union acceptance.