Alvin and the service life of deep-diving pressure hulls

What is the assessment of the Alvin deep-submergence vehicle?

Alvin receives strong praise; the wider safety argument concerns pressure-hull service limits and responding to structural warning signs.

Alvin is praised as an impressive piece of equipment. The wider criticism concerns a venture that dismissed safety requirements and continued using a pressure hull despite its limitations. A qualified counterargument allows that such a hull could survive a very limited number of deep dives and might be usable as a disposable component if its cost were low enough. That possibility depends on replacing it when necessary and responding to strain gauges or other instrumentation showing that the structure has changed.