Dennis S. wrote:

A related question, that perhaps Tony can answer off the top of his head, is when was wrought iron no longer used in freightcar construction? Did it last to the end of wood construction, or was it totally replaced by steel at some point either before or after the general change away from wood framing?

Wrought iron did continue to be used as small parts in car bodies, and in truss rods, for some time after steel replaced iron in virtually all large-scale applications. When steel suddenly became much cheaper than wrought iron in big sizes (once the Bessemer process reduced production costs to a fraction of previous costs), wrought iron continued to be well liked for its easy workability. So new bridge construction went quite rapidly went from iron to steel in just a few years in the 1880s. But car body construction may have continued to use some wrought iron later. I think wrought iron bar stock was readily available and in use as late as WW I.

A number of years ago, I was involved in scrapping some wooden Chicago elevated cars for parts . . . I've always wondered how long wrought iron plate and bar were produced after steel structural sections were introduced.

After about 1890, very little if any plate or large-section wrought iron would have been available. But small parts and tension rods may have been used in significant amounts for another decade or two.

Tony Thompson Editor, Signature Press, Berkeley, CA
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