Steam can be both lethal to an engine-room crew and intensely destructive to machinery, while some fuels are also hard on joints and materials. That makes metallurgy and the precise location of wear central to any life-extension decision. The key question is whether the machinery has simply reached old age or whether the installation contains a continuing cause of failure. A new engine is poor value if the ship was never arranged to receive it or if the same corrosive and structural conditions remain. The engineering diagnosis has to precede the procurement decision.
Chapter · 15:27-16:31
Machinery wear reflects how a ship is operated
Begin the machinery test with failure causes: corrosive steam and fuel, metallurgy, joints, and replacement access all matter before a navy orders a new engine.