Charges for use by Board of transmission lines and main transmission lines

-1 I. The following charges and allowances shall be made in respect of a year of account for the use by the Board of main transmission lines or transmission lines (hereafter in this Schedule referred to as lines), namely :- (a) the actual cost of maintenance of the lines, including renewals thereof not chargeable to capital account ; (b) sums paid in respect of the lines for insurance and as rents, rates and taxes including all taxes payable on income and profits ; (c) the proportion of management and general establishment charges properly attributable to the lines ; (d) any other expenses on revenue account properly attributable to the lines ; (e) interest on the depreciated cost of the lines shown in the books of the undertaking and properly attributable to the lines (whether defrayed out of capital or revenue) and interest on such working capital as is properly attributable to the lines : Provided that for the purpose of ascertaining the principal on which interest is payable within the meaning of this clause, there shall be left out of account any part of principal, interest on which is charged to capital ; (f) an allowance for depreciation of an amount determined in respect of the lines in accordance with the provisions of paragraph VI of the Sixth Schedule. II. If the lines are used partly by the Board and partly by the licensee owning them, or if the arrangement for their use comes into force or determines otherwise than at the beginning or end of a year of account, the charges and allowances referred to in paragraph I shall be the proportion thereof having regard to the use made of the lines by the Board and the period of such use during the year and with the addition of the cost of such additional transmission losses as may have been incurred by the licensee as a result of the Board's user of the lines. III. For the purposes of clause (e) of paragraph I the rate of interest shall be- (a) where the licensee owning the lines is a local authority, the average rate payable on the money raised by that authority for the purpose of constructing the lines ; (b) in any other case, the Reserve Bank rate ruling at the beginning of the year referred to in paragraph I plus two per centum.