Distortion and visible structural patterning show why hull life involves more than cosmetic corrosion. The Type 23 was conceived as a relatively light frigate rather than the longer-service role intended for the Type 22, so its original structure matters when service is extended beyond the initial plan. Repeated work in the North Sea and North Atlantic accumulated stresses that help decide which ships can accept thicker plating and a rebuild. A ship may have been reliable precisely because it spent more time at sea, yet that successful service can make a major refit less viable. The useful measure is the remaining value of the structural platform, not its reputation alone. Hull and engines are deep, heavy core systems, whereas lighter equipment higher in the ship is usually easier to replace.
Notable Point · 21:12-24:18
A reliable Type 23 may still be uneconomic to refit
Use the Type 23 frigate example to see why visible rust is less revealing than structural fatigue, operating history, and the ability to accept a repair.