The Zink Tronk, built during the 1960s from corrugated iron, was a large rectangular building with guard posts at each corner and a large courtyard in the middle. It was specifically built to house large numbers of prisoners and had general cells, a library, ablution facilities and a clinic.
The Zink Tronk was barricaded by a high fence, built on the north side of the current MSP, next to its F and G sections. After the MSP was built, the area of the Zink Tronk was used as a sports field and tennis court by the general section prison population. The Zink Tronk was demolished in the mid-1970s.