11. Appointment of consulting engineer.- For the purpose of assisting the Central Board in the performance of its functions, the Board may appoint a consulting engineer to the Board for a specified period not exceeding four months: PROVIDED that the Board may, with the prior approval of the Central Government extend the period of the appointment from time to time; PROVIDED FURTHER that if at the time of the initial appointment the Central Board had reason to believe that the services of the consulting engineer would be required for a period of more than four months, the Central Board shall not make the appointment without the prior approval of the Central Government. | 