I'm trying to identify this symbol coming from a 1985 electrical single line diagram (from a marine engineering project).
It looks like a closed disconnector switch or a styled fuse maybe?
Here is some context around the symbol:
It's a cartridge circuit breaker as per this website entitled Electrical and Electronic symbols: -
The bigger question will inevitably be - did the person making the diagram back in 1985 adhere to the standards or, were the standards of today the same as they were in 1985.