Complex sentence: The Trent name had been used for two previous Rolls-Royce engines, The first Trent was the world's first turboprop engine and the name was reused in the 1960s for the RB203 bypass turbofan, designed to replace the Spey.
Split into simpler sentences: The Trent name had been used for two previous Rolls-Royce engines. The name was reused again in the 1960s for the RB203 bypass turbofan designed to replace the Spey.