No railroad shall be constructed to cross another railroad at the same level therewith or across navigable or tidewaters without the consent, in writing, of the Public Service Commission, nor except in such manner as it shall prescribe. It shall be unlawful for any corporation proceeding to construct a branch or extension or otherwise to take any proceedings contemplating a new crossing of one railroad with another, at the same level therewith, unless such crossing shall first have been approved, in writing, by the Commission and the preliminary approval of any plan for such crossing shall always be made subject to revision by the Commission. The court of common pleas shall have full equity jurisdiction of the provisions of this section.