The second-in-command of Hong Kong's prisons will be promoted to head of the Correctional Services Department next month when his boss retires. The appointment of Sin Yat-kin, a deputy commissioner of correctional services, was one of several announced yesterday. Sin, 52, will assume the rank of commissioner on September 20. He will take over from Kwok Leung-ming, 57, who retires after 37 years of service. Both have been career prison officers, working up through the ranks in the 1970s. Assistant Commissioner Yau Chi-chiu will succeed Sin. The department also said Au Lok-wah, a senior superintendent of the Hei Ling Chau Correctional Institution, was promoted to senior superintendent of the department. In other appointments, Lau Ka-keung, the director of drainage services, will become the director of highways on September 3. He will succeed Wai Chi-sing, who was named permanent secretary for development in June. Chan Chi-chiu, a project manager of the Civil Engineering and Development Department, will replace Lau. Secretary for the Civil Service Denise Yue Chung-yee said she was confident the new appointees will be able to lead their various departments. 'The appointees have proven leadership and administrative skills, as well as profound professional experiences and broad operation experience,' she said. On the retirement of Kwok, Yue praised him for his 'sustained efforts' in leading the department to provide a secure, safe, humane, decent and healthy environment for people in custody. 'Mr Kwok has served with zeal and commitment in the civil service throughout the years ... We sincerely wish him a happy retirement.'