I tried posting from my mobile. Big failure. I'm sure it is my fault so back to using my laptop.
A note for those who might correct me. I have never been inside Port Phillip Prison, nor do I wish to spend time there. Unsurprisingly the company that runs the prison does not publish much detail of its layout. Therefore, the internal layout is entirely my own invention, based on what I could find out about modern prisons I think it should be mostly OK.
The production of fletchettes, compound sling shots and spear type weapons is something that is well documented on youtube. It is fascinating to see how easy it is to make a weapon as powerful as a .45 handgun.
Custom made melee weapon (like a Lucerne hammer)
Slingshot versus handgun