37 Construction repair and installation services, namely, building construction and repair, construction of airports and harbours, construction and repair of roads, bridges, tunnels, underground facilities and dams, construction of solid waste treatment plants, construction of water treatment and purification plants, construction of hydro-electric factories, construction of electricity and telecommunication towers, pipeline construction, maintenance and repair, construction planning, management and consultancy, consultation services in the field of vehicle, aircraft and boat building, conversion, renovation and repair, installation, repair and maintenance of heating equipment, gas turbine engines and nuclear power plants, repair and maintenance of medical machines and apparatus, maintenance and repair services for electric generators and wind turbines, installation and maintenance of photovoltaic installations, installation and maintenance of geothermal and solar energy based power plants, installation and maintenance of telephone lines, installation, machinery installation, maintenance and repair of computer hardware