Townsend Redoubt,part of the original lines was made obselete when the Lines were extended to St Marys Creek.
By 1819 although still listed as a defensive work it was now being used as a dwelling House.
St Marys Barracks were built between 1807-1812.They were a large red brick casemated blockhouse behind the Demi-Bastions and Curtain Wall opposite the Lower Lines.
They were built to house Troops and contained artillary to arm this section of the lines.
A smaller Blockhouse was built in the Redan next to it.
In the 3rd quarter of the 19th century the barracks became a Factory producing the Brennan Torpedo - Invented in 1873 by Louis Brennan, and a forerunner of all wire-guided weapons.
Unfortunatly the Barracks were demolished in the 60's.