§ 22. Detailed plans; sub-surface structures. a. When the consents of the board of estimate, the mayor and the property owners, or, in lieu thereof, the authorization of such appellate division of the supreme court upon the report of commissioners, shall have been obtained, the board of transportation shall at once proceed to prepare detailed plans and specifications for the construction of such railroad in accordance with the general plan of construction, including all devices and appurtenances. Such board, in its discretion, may include in such plans provisions for sub-surface structures, whenever necessary so to do, in order to permit the proper construction of any railroad herein provided for in accordance with the plans and specifications of the board of transportation or for any other purpose in furtherance of the public interest or convenience.

b. The board of transportation, from time to time, may alter such detailed plans and specifications, but always so that the same shall accord with the general plan of construction; but whenever a contract shall have been made for the construction of any railroad herein provided for, no such alteration shall be made by such board without the consent of the contractor and his sureties, except as liberty shall have been reserved in such contract by such board for such alteration.

c. Whenever the construction of any railroad, depressed way, subway or tunnel under the provisions of this chapter shall interfere with, disturb or endanger any duly authorized sub-surface structures, the work of construction at such points shall be conducted in accordance with the reasonable requirements of the agency of the city having the care of and the jurisdiction or control over such sub-surface structures so interfered with, disturbed or endangered.

d. Where, under the direction of the board of transportation or in pursuance of any general plan adopted or of any contract made by such board, galleries, ways, subways or tunnels shall be constructed to contain sub-surface structures, such galleries, ways, subways or tunnels shall be maintained by such city and shall be in the care and charge of the board of transportation and subject to such regulations as it shall prescribe not inconsistent with the provisions of this chapter. Any revenue derived therefrom shall be paid into the treasury of such city, except that where bonds shall have been issued to provide for the cost of construction or equipment of such railroads, such amounts shall be paid into the sinking fund of the city, if there be one, or if not then into the sinking fund to be established and created out of the annual rentals of such road, as provided in section thirty-four of this chapter. Provided, however, that any person who or which at the time of the construction of such galleries, ways, subways, or tunnels shall own sub-surface structures in a street in which such galleries, ways, subways or tunnels shall be constructed pursuant to this chapter, shall be entitled to the use of such galleries, ways, subways or tunnels for such sub-surface structures in the same manner as such person shall be entitled by law to the use of such street, and that no rent shall be charged for such use, except a reasonable charge to defray the actual cost of maintenance, unless such sub-surface structures shall be of greater capacity than those theretofore owned by such person in such street.

e. If the capacity of any such sub-surface structure, so placed in such gallery, way, subway or tunnel shall be increased, the rent shall be charged only for such increased capacity. The placing in any such galleries, ways, subways or tunnels of the sub-surface structures of any person owning such structures for electrical conductors, shall not in any wise affect the right of such person to charge and demand such compensation or rent for the use of such structures by other persons as is, or may be, permitted by law.

f. Nothing in this chapter shall be construed as granting, enlarging, changing, or in any manner validating any right, privilege or franchise, or any claimed or alleged right, privilege or franchise, to maintain, operate, or possess any sub-surface structures in any street.