The Transportation Board or selectboard shall ascertain, as near as may be, the original cost of erecting such line of poles, and shall direct such person or corporation as they may require to use such poles, to pay the owners of the line already erected a fair proportion of such expense, not to exceed one-half the estimated original cost of construction. In no case shall the poles be used until the owners of the new line tender to the original owners of such line of poles the amount so directed. When it is necessary to repair or renew the poles used by two or more persons or corporations, the expense thereof shall be borne equally by the parties using the same. (Amended 1989, No. 246 (Adj. Sess.), § 32.)