Charges and allowances for use of lines

The following charges and allowances shall be made in respect of a year of account for the use by the Board or the Generating Company 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