Tony Polson wrote:
"Recliner" wrote:
I agree that cars do have a much shorter design life, but it's certainly
more than five years and 60k miles.


It might be longer now, but it certainly wasn't in the 1960s. Ford used
5 years and 60,000 miles as their yardstick; the Austin/Morris Mini was
designed for 5 years but only 45,000 miles. I got that information from
a lifelong friend who worked for British Leyland/Austin Rover and is
currently at Ford, and whose father worked at Ford in the 1950s and 60s
and helped design the Cortina Mk1 and Mk2.

Mercedes Benz and Volvo have always had longer design lives, though.


Airliners have a longer design life,
but still not as long as trains (typically, 20-30 years).


True; fatigue plays an enormous role in aircraft life, and with fuselage
skin thickness measured in fractions of a millimetre, there is a lot of
scope for terminal corrosion.

Fatigue is critical for aluminium alloy structures such as aircraft,
because aluminium has no fatigue limit, meaning that airframes have a
service life limited by fatigue (with a suitable safety margin).
--
Jeremy Double {real address, include nospam}
Rail and transport photos at
http://www.flickr.com/photos/jmdoubl...7603834894248/