The first physical watchhouse for Tasmania occurred when a dedicated building was erected to add to the military guardhouse. In the ‘new’ building offenders of both genders who had been arrested by the watchmen were locked up until they went before the magistrate. After which they could remain in the watchhouse if they were ordered by the Magistrate to serve short periods of punishment in the cell, or cells depending on the scale of the watchhouse.
On the occasion of His Royal Highness the PRINCE REGENT'S Birth Day, His Honor the Lieutenant GOVERNOR was humanely pleased to liberate seven Prisoners under sentence in the Gaol Gang for various periods; and one female prisoner (wearing an iron-collar) confined in the Watch House. The Hobart Town Gazette and Southern Reporter, Saturday 17 August 1816 - Page 1
As the population of Van Diemen's Land grew and needs arose, watchhouses were built around the expanding colony. There were various uses for the Watchhouses as Guardhouses and Gatehouses, and within government institutions: Female Factories, gaols, prisoner barracks and other government premises including the New Town Farm, Brickfields, Queen’s Orphan School. South Hobart’s first police station was a watch house erected next to what is now Wheatsheaf Lane in Macquarie Street, in 1832.[*] The same year tenders were released for watch houses to be built on the New Town Road (see image below).
The Cascades Female Factory’s watchhouse was a place which offered female convicts employment, but only to the best behaved women. The ‘barracks duty’ task could earn the convicts credit by being employed to patrol the compound at night under the supervision of the Night Officer. However, if the watchwomen misbehaved or neglected their duty while on watch, including falling asleep on the job, their credit was removed and they would be sent to the wash tub or undergo some other appropriate punishment for several days. In 1852, Mary Ryan was given three days solitary confinement and dismissed from the watch for neglect of duty as watchwoman (lying down on a rug).
Watchhouse or Nightwatch duty within the convict institutions was also used as a punishment for convicts misbehaving. Several days of extra duty on ‘First Watch’ as a watchwoman, resulted in a late night after completing a long day working on otheir usual assigned tasks.
One of James Blackburn’s two ‘Watchhouses’, New Town
Tasmania Archives, AB 713-1-6077
Nightwatch and Watchhouses, contributed by T. Newman provides an insight into the nightwatch and watchhouses in Van Diemen's Land in the early 19th century.
George Town Watch House (including model and plans (TA PWD 2661285) for the 'Guard House': https://bassandflindersmuseum.com.au/the-watch-house
Plans for Watch House – Tasmanian Archives, Huon: PWD 266-1-1321 and Antill Ponds, PWD 266-1-1124
 T. Newman, Nightwatch and Watchhouses, Janurary 2022.
 'Convicts employed on Barrack Duties are to be allowed the average credit earned by the best behaved and most industrious women of the Establishment'. ML Tas Papers 187 CY 1927 Work of Female Convicts.