What a lot of folks don't know is that not EVERYONE who was banged-up in there were sex-offenders. In it's final 2 or 3 years of operating, prisoners, who had a year or less to serve of their sentence were moved from Craiginches Prison in Aberdeen because of the chronic over-crowding there to Peterhead. I know because I was one of them, and I wasn't sent to Craiginches for any sexual offences at all. I got handed a 2-year sentence for firearms offences (an illegal air-rifle!) and done 6 months in Craiginches, and the final 6 months in Peterhead (out after serving half your sentence if the initial sentence was 4 years and below).
It wasnt exactly a big jail. I always thought peterhead wasnt a big jail. Every time it was on the news and you saw a clip of it you just saw 1 big hall.
There were around 16 sex offenders in Peterhead who were totally segregated from the main prison population. I was there for 5 years , and during the riot.