Workers in this unit group perform technical tasks, normally under the direction and supervision of mechanical engineers, contributory to the design, development, manufacture, construction, installation, maintenance and repair of mechanically functioning plant and equipment. Their functions include: assisting in research and development work concerning machine tools, engines, vehicles, aeroplanes, heating, ventilating and refrigerating installations and other mechanically functioning plant and equipment; preparing detailed estimates of quantities and costs of materials and labour required for manufacture and installation; assisting with technical supervision of manufacture, installation, maintenance and repair of mechanical plant and equipment; applying knowledge of mechanical engineering theory and practices to recognise and solve problems arising in the course of their work.