Hi everyone,
I have what I think is an old Morrison road bike from the 80's (I'm not completely sure as I bought the bike already painted) and I have stripped the tread in the crank, rendering it useless. After a lot of searching, I finally found some second hand cranks in good condition that fitted, only to have them break again after 6 months.
I am fairly hard on my bike, but I would expect cranks to last a little longer than that, thats why I am looking to replace the bottom bracket. but its an unusual system and it doesn't appear to simply screw out.

Can anyone tell me a little more about this bottom bracket and how to replace it?

Thanks.

(I will try to attach some pictures later)