So, you want to break out of your cell? Unless you're Hercules, Superman or have a bag of explosives, you'll have a not very fun time trying to get through this several inch thick solid wood door lock and that heavy iron lock.

Some people did escape from the Gaol, but not many, and not by forcing or picking their way through locks like these. Two (named Smith and Staunton) crawled out through a sewer pipe which led to the cess pits outside the building in "Shawshank Redemption" style. People were a lot smaller then and they were able to get through a 13" (33cm) diameter pipe. Smith was recaptured within hours (all the warders had to do was follow their noses, I suppose), but Staunton got away to Sydney, where he was recaptured several months later... but then as he was being transported to Melbourne he escaped again and was never seen again.

In 1880 (yes, the time of the Kelly trial) a female prisoner named Ann Davis used the commotion of the Kelly circus to appropriate the clothes of the prison governor's wife and walk out of the prison. She remained on the loose for 3 years.