Propellers and Shafting for Sustainable Shipping
The importance of the line shafting, tailshaft, propeller, and thrust shaft cannot be over-emphasised. Failure of any one of them will rend the ship inoperable with possible disastrous consequences. Single line shafting is used on the majority of ships, but not in passenger ships and on short voyage ro-ro services where twin screws are employed. Propellers, because they are outside the ship, are often neglected and are usually only inspected when the ship is in drydock. More frequent examination can be undertaken when a ship is alongside and the shafting is being rotated with the turning gear. Damage to the propeller blade can lead to vibrations being set up in the line shafting causing overheating of the shafting bearings, main thrust, etc. The selection of shafting and propeller materials is usually within manufacturers’ specifications and complies with the various classification society requirements as well as the statutory requirements of governments.