 Construction of the northern wing followed, and by the start of 1857 the foundations were laid, and 40 % of the masonry works were done. However, the Crimean War saw the Royal Engineers recalled, leaving only Wray – as Acting Comptroller General, while Henderson was on leave in England – to oversee the prisoners'construction of the building. Much of the work was completed that year, including the remaining masonry, basement, slating the roof, and paving the corridor. While Henderson had wanted single cells, Wray conceded to the Governor's lobbying for additional capacity. He adjusted the design to include some double-width cells housing three prisoners, and triple-width cells holding five prisoners, allowing an additional 40 prisoners to be accommodated. Another measure that increased capacity was the lengthening of the northern wing by six feet (1.8 m). The justification was to mirror the southern wing, which had also been constructed six feet (1.8 m) longer than planned, due to inaccurate surveying. However, this also caused the project to run over budget. Stairs, guard railings, and doors were installed in 1858, and the prison was completed by the end of 1859, with Henderson back from leave and back in charge.
