My mother in law's parents were sent to prison for 1 months hard labour each in 1920.
Would the 3 jail's mentioned had the facilities for hard labour?
I think "hard labour" or labour of some sort would have been done at all major prisons.
Prison Act 1877 centralised the running of British prisons.
Prison Act 1898 made changes to prison labour. It was supposed to be productive and communal where possible instead of non-productive (e.g. treadmill) & solitary. There were 3 classifications of prison sentence, the most severe with hard labour. In practice courts were likely to hand down the most severe sentence.
"Looking at History - Prison regime 1880-1914"
https://richardjohnbr.blogspot.com/2011/04/prison-reform-1880-1914.htmlRegime in prisons became significantly less harsh after 1922.
Sentences with hard labour were abolished in 1948.
https://www.nationalarchives.gov.uk/help-with-your-research/research-guides/prisoners-or-prison-staff/"Crime and Punishment in England 1850-1922" by Martin J. Weiner
"The State of the Prisons in Britain 1775-1905" W.J. Forsyth
"English Local Prisons 1860-1900" S. McConville
"English Society and the Prison: Time, Culture and Politics in the Development of the Modern Prison, 1850-1920" by Alyson Brown