Section 12(1) in The Assam Engineering (Irrigation Department) Service Rules, 1978
(1)All vacancies in Class I cadres shall be filled by promotion :Provided that the Governor may, for good and sufficient reasons, fill up any of the vacancies in Class I (Senior Grade) for specialised investigation, design and research work on a purely temporary basis either on tenure or by transfer on deputation of officers from outside the service or in any other cadre for any specialised work, by inter-departmental lateral transfer on a purely temporary, basis, of officers among Public Work, Irrigation and Flood Control Departments, subject to the following conditions :(i)The Governor is satisfied that there is no suitable officer available in the service for filling the vacancy ;(ii)The specialisation needs of the department are adequately ensured by the arrangement;(iii)The officer so taken to a department shall not have any claim for any promotion in that department; and(iv)In case the Governor is satisfied that the Officer so taken to a department for a specialized work cannot be withdrawn from the work due to non-availability of any other officer of an equivalent status in the department for that work. The officer so taken to a department shall be granted all promotions proforma, whatsoever may be due to him in respect of his original service.
