Metal crosses on old buildings

[Richie616]

What are those metal "X" crosses on the external walls of old buildings called and what is their purpose? They are particularly popular on old barns.

[gen2]

They are the ends of ties that hold the walls together. A long rod goes right through the building, the ends are threaded and a large nut is screwed on each end. The rod may be heated when installed so that when it contracts, it pulls the walls together. The large cross is to spread the load (force) across the wall. Sometimes , instead of a cross, you see large S shapes. Smaller, or less visual buildings may simply have a large rectangular plate instead.

[Richie616]

Thanks for quick reply. I now feel enlightened, thanks. I'll impress the wife now next time we drive pass them!