Mainshafts for the Trent

Reports on the development of the Super CMV mainshaft for the Trent class jet engine from Rolls‐Royce. Describes in depth how the new mainshaft was designed to outperform the earlier generations. In comparison with the previous generation, the new mainshaft, through the use of improved materials, is able to cope with approximately twice the amount of torque transmitted to the fan, has a shaft weight per unit of transmitted torque ratio of 25 per cent less, a diameter that is similar in size, and yet was still able to be manufactured at a similar cost. Also reports on the increase in fatigue lives for the shaft oil holes and splines that was achieved through design improvements.