"Made in Van Diemen’s Land (Tasmania) between 1830 and 1849, the fabric was probably woven and then made into uniforms in the Female Factory in Hobart. Natural dyes were used to colour the cloth. The woollen fabric is heavy and rough, and there are buttons down the side of each leg, allowing a prisoner to remove his trousers while wearing leg-irons. The ‘broad arrow’ indicates that the wearer was government property." From: https://www.nla.gov.au/digital-classroom/year-5/convicts-conflict-and-confrontation/themes/convict-experiences
It looks like the "belt" held the pants up.
A better look at the "belt". Notice the buttons down the right leg so the pants could be removed with leg iron on the ankles.
A picture of the shoulder and collar. (Yes, it is REALLY old.)
From Wilipedia https://en.wikipedia.org/wiki/Prison_uniform:
"... dangerous criminals, usually those held in Category A maximum security prisons, who are assessed as having a high escape attempt risk; they are required to wear yellow and green boiler suits with the words 'HM PRISON' ('HM' standing for His/Her Majesty) printed on the back in black capital lettering on a permanent basis whilst in custody. This uniform is known as an "Escape risk suit". Such prisoners are also handcuffed and sometimes fitted with a leather belly chain when moved outside of prison to places such as court buildings.
Blue & yellow. This appears to be a shirt & pants, not a boiler suit.
Google Translate: HOW TO GET OUT OF A STRAITJACKET?
A Russian escape from a straitjacket & strait-coveralls.
youtube
Googles closed caption translated to English worked for me.
Zipper back closure. Many repairs. 15 minutes and 21 seconds long.
Google Translate: Finally, the long-awaited straitjacket has arrived. Today we’ll check whether it’s possible to get out of it without outside help, and if so, we’ll show you how to do it
The steel arm is placed flat against the wall with the section with the hole in it goes into the slot. When the solid outer door is shut, the steel arm is locked in place.
Available on Google Streets: https://maps.app.goo.gl/tT4KQPafwHKeWQwz5