Rusty foundation grillage

[oakcroft13]

Reading David's note about Oldham reminded me that I was at Merthyr 
Tydfil a week ago recording and inspecting (results to be written up 
ASAP, v. interesting). The foundation beams there are fabricated: 
rivetted up from plate and angle. Some of the plates had started to 
laminate through rust. To my uncritical eye there was nothing the 
threaten the stability of the installation, but I had not thought of 
the rust cracking the castings. Is this a common occurrence?

Bill H