The high cost and complexity of modern ships may point to an alternative to the sale or scrapping a vessel as it ceases to fulfill all the requirements of its original task.
In some cases new or upgrading older engines, in other cases the propulsion configuration is changed, rewarding the operator with lower fuel costs and emissions.
“Nothing lasts forever” applies equally well for ships as for the rest of life!
Even in the relatively short life of a ship its role and therefore usage profile changes through the years. Work patterns environmental issues, fuel costs are all changing during the ship’s life and the specification of equipment, particularly propulsion while optimum at the initial design stage may rapidly become uneconomic or even socially unacceptable as the ship goes through life. The high cost and complexity of modern ships may point to an alternative to the sale or scrapping a vessel as it ceases to fulfill all the requirements of its original task.
An alternative is a major refit, such as is commonplace in naval warships, but less common in commercial ships with the possible exception of the cruise ship industry where longer ship ages are more common.
Replacing propulsion machinery is a costly item however the benefits are many. In some cases just fitting more efficient new or upgrading older engines will reward the owner with lower fuel costs and emissions.
In other cases the refit is more rigorous with the propulsion configuration being changed. For example the gas turbo electric
Radiance Class cruise ships fitting an additional diesel gen set to give a combined turbo electric or diesel electric propulsion configuration. In other cases such as the Norwegian Coastguard vessel
KV Harstad the diesel mechanical propulsion system has been converted to diesel electric claiming a reduction in fuel consumption and emissions of 50 per cent.